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XD11
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Minolta XD-11 Service Manual

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Minolta XD-11 Repair Gui de
Figure IB
OVERRANGE LED
SHUTTER-SPEED SCALE
UNDERRANGE LED
DIAPHRAGM WINDOW
Figure 3 Figure 4
ring then c omes against the minimum- aperture lever, Fig. 1. As t he tab pushes the minim um-aper ture lever from lef t to rig ht, it programs the meter ing sys tem for the smallest f/stop of the particular lens.
Only the MD series of lenses has the mi nimum-aperture tab on the diaphragm- settin g ring. Although t he earlier MC lenses will couple to the diaphragm- metering ring, they don' t have the tab whi ch position s t he minimum-aperture lever. So, if you install an MC lens on the XD-11, th e LED display won't indicate an automatically programmed f/stop. You'll only be able to turn on one LED — t he
over range LED.
You'll also get n o diaphragm readout if you fo rget to set the smallest f/stop on the MD lens. The c alib ration for the smallest f/stop has a green color code.
Since an optical sy stem reflects th e select ed calibration in to the finder, you can quickly set the d iaphragm for the "S "
mode. Simply rotat e the diaphragm- se tting ring until t he green number ap
pears in the finder, Fig. 4.
Now turn the speed knob to select the shutter speed you want. As lo ng as t he LED display indicates an f/stop in the usable diaphragm range, the camera delivers the shutter speed you've selected. It then limits how far the dia phragm can close according to your select ed s hu tte r speed and to t he light conditions.
Since the XD-11 alr eady has shutter- speed control circuitry, it can go an e xtra step to make su re you don't get an inco r
rect exposure. Perhaps the camera can't progr am the r ight f/stop for the partic ular combi natio n of light level and shutter speed. A glanc e at the LED readout tells you to s elect a different shutter speed. But, if you fail to make the necessary cor rection, the camera's "comput er" takes over — it automati cally changes the shut ter speed for you.
The camera lets you know when you're going to get a shutter speed that' s dif feren t from the one you've selected — it turns on one of the range-limits LEDS as you star t depressing the release button. If the overrange LED turns on, you’ll get an exposure tim e that's faster than the speed- kno b se tting. If the underrange LED turns on, you'll get an exposure time that's slower than the s peed-knob setting.
To program the diaphragm open ing, the XD-11 contr ols the movement of the diaphragm-closing lever, Fig. 5. The
diaphrag m-closing lever moves from ri ght to left before the mirror swings to the tak ing position. If the diaphragm-closin g lever moves its ful l d istance, it all ows the dia phragm to stop down to the smallest
f/stop. However, by l imi ting t he move
ment of the diaphragm-closing lever, the XD-11 selects other aperture sizes.
A comb ination magnet (permanent
magnet plus electromag net) limits the m ovement of the diaphragm-closing lever. As the diaphragm-closing lever sta rts to move, the permanent mag net
holds its armature. Then, when the dia phragm reaches the proper o pen ing size, the ci rcuit discharges a capacitor th rough the coil that's wound around the
pe rmanent- ma gnet c ore. The s purt of
current momentarily disables the perma
nent magnet.
Now the armature of the combina tion
magnet jumps away from the core. And the pawl-shaped end of the armature
engages the ratchet teeth of a gear whi ch
rotates as the dia phragm-c losing lever
moves. Stopping the r otation of the gear
also stops the movement of the
diaphrag m-closing lever.
In tu rn, the dia phr agm-closing lever
sto ps the spring-loa ded diaphragm from
closing any f urther. At t he other settings
of the mode selector, the capacitor nev er
disc harg es through the coil of th e com
bination magnet. As a result, the
diaphrag m-closing lever always moves its full distance. And the diaphragm stops down to the f/stop you 've selected on the diaphragm-setting ring.
The third setting o f the mode selector
— the "M " sett ing, Fig. 2 — provides ma nually calibrated shutter speeds. Wi th the m ode selector at "M ," the shutter alw ays deliv ers the selected shutt er speed. The LED display now serves as a
cross-c oupl ed mete r; it tells you w hat shut ter speed wil l provide proper ex
posure according to the light conditions
and to the diaphr agm setting . A lso, as
you turn the mode sele ctor from the "A "
position to the "M " po sitio n, the
viewfinder mask uncovers t he shutter-
speed calib ration in the finder, Fig. 4.
Although the speeds are manually select ed at the "M " mode, t hey're still ele ctronically controlle d. Co nseq uently, all th ree functions dep end on battery
power . In fact, even the s hu tte r release requires battery power. A second com bination magnet in the XD-11 releases the mirror when you push t he release button far enough to close the release switc h.
The XD-11 uses two S-76 silver-ox ide batteries housed at the bott om of the camera. What if the batte ries die? Yo u'll then find that the shutter won't release.
But t he XD-11 does pr ovide two
mechanical settings — "B " and " 0 ," Fig.
2. At the "B " sett ing, the shutter delivers
a mechanically contro lled bulb action. A mechanica l system then releases the mir ror. At the " 0 " setting, the shutter mechanica lly delivers the f astest full- aperture shutter speed — 1/10 0 second. So, if the batteries die, you can turn the speed knob to "0" and contin ue using the camera with electronic flash.
The electron ically con trol led "X" set
ting also provides the fla sh speed of
1/100 second. However, the " X " sett ing does depend on battery power — both for the electromagnetic release and fo r
Figure 5
Figure 6 Front-plate/mirror-cage/shutter assembly
the electronically timed exposure. You
can't use t he " X " sett ing, the "B " set
ting, or the " 0 " setting for au tomatic e x posure control. To help p revent a possible operator error, the LED display refuses to indicate a shutter-speed or diaphragm calibration at the "X ," "B ," or " 0 ” set tings, Rather, the overrange LED always turns on.
OTHER FEATURES OF THE XD-11
The XD-11 and its spinoff, the XD-5, both use the Seiko MFC modular focal- plane shu tter. With a modular focal-plane shutter, you might expect the XD-11 to have a mo dular design. It does. But the XD-11 is even more modular than most cameras using similar sh utters. You can remove the front plate, mirror cage, shutter, and flex circuit as one unit. Reaching the shutter takes a minimum amoun t of time.
Practica lly all of the electroni c com ponents mount to the flex circu it. In many cameras, the flex cir cuit causes repair problems; y ou must delicately li ft aside portion s of the flex circuit to disassemble the camera. Howeve r, the XD-11 elimi nates such problem s. Since the flex cir cuit c ome s off with the front assem bly, Fig. 6, there's little c hance of da mage.
As is typical, the flex circuit covers the penta prism. Fortunately, you don't have to lift aside the flex circuit to clean the f ocus ing screen. For that ma tter, you don't even
have t o remove the top cover. To remove the f ocusin g screen, take out the two screws that hold th e plate at the top o f the
mirror cage, Fig. 5. Lift out the cover plate and th e focusi ng-sc reen retainer. You can
now drop out the focusing screen from in side the mirror cage, Fig. 7.
Most of the remaining featu res are pretty typical of modern SLRs. Notice that the fil m-speed dial allows you to set
intent ional o verexposures or underex posures, Fig. 2. When you select the fi lm speed, the film-speed dial rotate s a brush
along the fil m-speed re sistor. Movin g the compensation lever fo r intentio nal over- exposures or underexposures rotates the enti re fil m-speed resistor with out moving the brush.
The XD-11 also accepts a p owe r winde r, the Aut o Wi nder A, and th e Minolta series of dedicate d flash unit s. The 132X, 200X, and 320X dedicated flash units automa tic ally progra m the camera for the flash speed of 1/100 second. When the flash unit charges, the ov errange LED flashes on and off in t he fin der.
CIRCUIT A T THE BOTTO M OF TH E XD-11
The batt ery-compartment cover screws into the bottom plate. So, once you remove the bottom plate, you can't power the camera with its own batteries. However, you can con nect a 3V DC power supply to the batt ery com partment, Fig. 8. Conn ect the positiv e pow er-supply lead to the batt ery- compar tme nt termina l and connect the negative power- supply lead to ground (any metal part on the camera). All the test v oltages we'll be giving are positiv e wit h respect to ground.
As you cock and release the shutte r, no tice the ac tions of the two levers at tached t o the t ransport cam — the mirror- cocking lever and the shutter-cocking lever, Fig. 9. T he clockwise rotation of the t ransport cam drives t he mirror-
cocking lever left to right in Fig. 9. T he end of the mi rro r-cocking lever then comes against the roller on the mirror- tensioning lever to charge the mirror. At the same time , the tran sport cam draws the shutter- cocking lever from left to right to charge the Seiko shutt er.
The transport l atch , Fig. 9, now drops into engagement with a notch in th e transport cam. Consequently, you can't advance the wind lever a se cond time. A fter the exposure , the mirror-ten sioning
lever swings f rom right to left, Fig. 9, and strikes the transport-releas e lever. As the transport-release lever rotates in a clock wise directio n, it dis engages the
transport latch fro m the tra nspo rt cam.
A spring attached t o the transpo rt latch and the transport-release lever provides the swi tching contact for the power
winder. With the shutte r released, the
power-winder switching contact moves into the power -winder locating bushing. Fig. 9. The locating bushing receives a pin on the power wind er. So, with the power winder attache d to the camera, the power-winder switchi ng contact touches the pin.
The po wer-winder switching co ntact now connec ts the p ower -winder pin to ground. As a result, the powe r winder goes into action; it advances the film and coc ks the shutter by rotating the pow er- wind er coupler, Fig. 9. When the shutter reaches the cocked position , the trans port latch drop s into the notch in the transp ort cam. The transport latch no w drives the power-winde r switching con ta ct away from the power-winder pin. Since t he power- winder pin no longer connects to g round, the power winder
sto ps runn ing.
At the other en d of the camera, you can see th e circuit board which contains
the mirror-re lease and diaphragm -co ntrol
component s. Fig. 8. Locate the two cap a citors — C5 and C6. These are the capa-
Figure 8
POS IT IV E BATTERY
LOC AT IN G BUS H IN G
POW E R -W IN D E R SW IT C H IN G CON T A CT
POW E R -W IN D E R COU P L ER
TR A N S P O R T CA M
Figure 9 Shutter Cocked
MIR R O R -C O C K IN G LEVER
LOOS E DU ST SEAL
IR A N S P O R T - RELEA SE LEVER
SHU TT E R C O C KI N G LEVER
citors that discharge through the coils of the comb ination magnets. C6 discharges through the coil of the mirror-release co mbin ation mag net M1; C5 discharges th ro ugh t he coil of the diaphragm-control co mbin ation magnet M2.
As yet, you can't reach th e combina tion magnets. So , if there's a prob lem in either the mirror-release circu it or in the diaphragm-con trol circuit, you m ay have to remove the front-plate as sembly. However, you can troubleshoot both cir cuits and pinpoin t the malfunction with
out further disassembly. And, if you find
th at the problem is on the circuit board,
Fig. 8, you can ma ke the repa ir without
disassembling the camera any further.
The two combina tion magnets have very similar circu its. Fig. 10 shows the cir cuit for th e mirror-release magnet M1. Transistor T6 serves as a swit ch between
the mirror-release ca pacitor C6 and the coil of the mirror-release magn et M1 . Turning on T6 a llows the capacitor to discharge through the coil. The spu rt of current
causes the armature of M1 to jump a way
from the c ore and release th e mir ror.
You can see the M1 armature in Fig. 11. Also locate the mirror-release lever in the same ill ustration. When you push the release button, you should see the end of the M1 a rmature move toward the front of the camera and strik e the mirror-release
lever.
Transistor T6 gets the release signal from the compara tor, Fig. 10. When the release switch closes, the contro l circuit sends a signal to the compar ator. T he compar ator then sw itches from a h igh state to a low state. The low volta ge ap
plied to the base of T6 turns on the tran sistor. T6 now allows the capacitor to
discharge through the coil of M1.
But notice in Fig. 10 tha t switch S1 must be closed before the compar ato r output connec ts t o the base of T6. S1 sits at the bottom of the camera, Fig. 11. When you cock the shu tter, S1 closes to connect the comparator to T6. S1 opens after th e exposure.
You can also see the part that a ctuates S1 in Fig. 11 — the nylon lug on the transport-releas e lever. As the transport- release lever swings in a clockwise direc tion, it allows S1 to close. Then, when the mirror-tensioning lever drives the transport-r elease lever in a counter clockwise d irection, the nylon lug pushes the long blade of S1 away from the short
blade.
S1 serves as a reset swit ch for th e cir cu it. But, if S1 fails t o close or makes poor electrical con tact, you'll only note
Figure 10
Figure 11
one malfunction in the camera — the shutter won' t release. With S1 open, transist or T6 ne ver gets the lo w-voltage signal from the com parator.
You can check S1 with a voltmeter. At the long blade of S1, Fig. 12, you should measure 0V with the shutter in the released position. You should measure around 2.5V at the short blade, regardless of wh ether the shutter is cocked or released. Since S1 should close when you cock the shutter, you should also measure around 2.5V at the long blade. What if you measure 0V at the long blade wit h the shutter cocked? Ap parently, S1 isn't closing.
If you have to reform the blades of SI, check the timing. Cock the shut ter and hold the win d lever fully advanced. Then,
while measuring the voltage at the long
blade of S1, allow the wind lever to return slowly to its rest position. S1 should re main op en as the transport latch drops into the first step in the tr ansport cam, Fig. 9. But S1 should close w hen the tra nsp ort latch drops into the seco nd tran sport -cam notch. So, as soon as the transpo rt latch
drop s into engagement with the second
notch, you should measure a round 2.5V at
the long blade of S1. If the timing isn't cor rect, reform the S1 blades.
TROUBLESHOOTING THE
ELECTROMAGNETIC RELEASE
SYSTEM
If the shutter fa ils to release elec- tromagnetically, you might first suspect swit ch S1 . B ut you can also check the other possibilities after remov ing the bot tom plate. The mirror-release magn et M1 may have an open coil, the mirror-relea se capacitor C6 may be op en or short ed, tra nsi stor T 6 may be open, or T6 may n ot be gettin g the release signal from the comparator .
It's also possible that the problem is mechanical rather t han electronic. To check the mechanic al release acti on, cock the shutter and push the M1 armature.
Fig. 11, toward the front of the camera. The mi rror should release. If it does, you know t he mecha nical release is working
properly. And the problem must be with
Figure 13
the circuit.
Fig. 13 shows the appr oximate voltages you should measure acro ss th e M1 com ponents. Notic e that the mirror-release capacitor C6 charges t o the full battery volt age. You should measure the +3V at the pos itive terminal of C6 regardless of whether the shutter is cocked or released.
However, before measuring voltages, you might try a quick shortin g te st to simultan eously check both capaci tor C6 and the coil of magnet M1. Cock the shutter. T hen bypass transistor T6 by shorti ng betwe en its emitter and collec tor, Fig. 13. The mirror should release.
If your shorting test releases the mirror, you know that both th e c ombination ma gnet M1 and the m irror-rele ase capa citor C6 are good. You migh t nex t t ry checking for the release signal at the base of tr ansistor T6, Fig. 13. Without de
BLA CK (GROU ND)
RED TO
* BATTERY
pressing th e release button, you should measure around 2.5V — the output of the co mparator in the "high" state . I f you measure the full 3V sign al, T6 a pparently
has a b ase-to-emit ter short. Now depress the release button. T he signal should drop to around 1.3V.
If the circuit fails to supply the release signal to the base of T6, you'll have to go further in the d isassembly. There may be a problem with the release swit ch or with the release cir cuit. But if the t ransistor T6
is a t fa ult, you won't have to go an y fur the r. You can make a fin al check on T6 by shorting between the base and the collec tor, Fig. 13. Your short connects the base to ground through the coil of M1. If the tra nsistor is good, the mirror s hould
release.
Replacing the tr ansist or gives you a
choice in repair procedure. Minolt a does supply the individu al components. But you may prefer to replace the com plete circuit board (circuit base plate B).
Now let's say that the shutter doesn't release whe n you short betwe en the emit ter and collector of T6. Either the com binati on magnet M1 or capacitor C6 could be at fault. But you might first suspect the coil of M1. The red wire co nnected to the collector of T6 goes to one si de of the coil; the other side of the coil connects to ground through a black wire, Fig. 13. To check the coil, m easure the resis tance bet ween the red coil wi re and groun d. You should measure a very low resistanc e
— arou nd 15 oh ms. I f you measure no con tinuity, you know that the combina tion magnet M1 has an open coil. You'll then ha ve to rem ove the front -plat e asse mbly to replace the combination
magnet.
Figure 14
CHE CKING THE DIAPHRAGM- CONTROL CIRCUIT
You can fol low practically the same troubleshooting procedure to check the circuit f or th e sec ond combination magnet — the diaphragm-control magnet M2. Remember, the diaphrag m-control magnet arrests the diaphragm closure in the "S " mode. If the re's a problem in the M2 control circuit, the diaphragm always stops down its fu ll amount.
In Fig. 14, note the similarit y between the diaphra gm-control circuit and the mirror-release circuit. When th e dia phr agm reaches the proper f/stop, the aperture-control co mparator switches on transistor T13. T13 then supplies th e base current which turns on t ransistor T5. Turning on T5 allow s th e diaphragm- cont rol capacitor C5 to discharge through the coil of the diaphragm -co ntrol magnet M2. M2 now repels its armature to arrest the diaphragm-closing lever.
Figure 15
Figure 16
Figure 17
BL ACK PURPLE
WHITE TO S7
VIOL ET
BROWN TO M2
BLUE
The components for th e diaphragm-
control circuit also mount to the circuit
board a t the bottom of the camera, Fig. 15. But you can't as yet see switch S7. Switch S7 is part of the mirror-release-magnet assembly M1. As th e armature of M1 jumps away from the core to release the mirror, it opens S7. Not ice in Fig. 14 that S7 mu st be open in order for transistor T13 to conduct.
In effect, ope ning S7 turns on the diaphragm-con trol circuit. At the same time, S7 provides power for th e shutter elect romagnet (the electromagnet th at
holds open the closi ng blade for the length of th e exp osure). Opening S7 also switches off the LED display.
A problem with S7, then, could cause
quite a few problem s. Althou gh you can't as yet reach S7, you ca n check i ts opera tion. Lo cate t he white wire attached to the lower circuit board, Fig. 15. Measure the voltage bet ween th e white wire and ground; you should measure 0 volt, in dicating that S7 is closed.
With S7 o pen, you should measure
aro und 1.3V at the white wire. But how
can you op en S7 to measure the voltage? One way is to hold open t he s hutter at the bulb setting. Then push the M1 ar mature. Fig. 16, away from the M1 core (toward the front of the camera). The M1 ar ma ture now opens switch S7. Conse quen tly, you should measure around 1,3V at the white-wir e connec tion, Fig. 15.
Th e technique f or holding open switch S7 also allow s you to conv eniently che ck the c oil of M2 and ca pacitor C5, Fig. 14. Con side r that the diaphragm-control cir cuit fails t o latch the diaphragm-cl osing lever; the d iaphra gm-closing lever a lways moves its full distanc e in the "S " mode. You might first check for the charge across the diaphra gm-control capacitor C5. Me asure the volt age between gro und and the pos itive C5 lead. Fig. 15; you should mea sure -t-3V.
If you're gett ing the full battery voltage across C5; th e problem could be with T5, T13, or the coil of M2. Another possibilit y is that T13 is n't getting the turn-on signal from the aperture-cont rol comparator. But you can quickly check the trans istor s and the M2 coil with shorting tests.
There are a couple of ways you can check to see if M2 repels its arm ature when C5 discharges. Try setting the mode selector to the " S " position. Then watch the diaphragm-closing lever, Fig. 5, as you
release the shutter. If there's a problem in the diaphragm-cont rol circuit , the diaphragm-closing lever always travels its full str oke.
Now short betwee n the emitter and collect or of transistor T5, Fig. 15, as you release the shutter. The diaphragm- closing lever should stop after t ravelin g a
short distance. If it doe sn' t, you know that the diaphragm-control magnet M2 and the diaphr ag m- control capacitor C5 are both doin g their jo bs.
But you may fin d that it's easier to check the opera tion if you can actually see the ar mature of M2. Just pull aside the battery compartme nt by removing its two screws, Fig. 16. You can now see the M2 assembly through a clearance cu tout in the bottom of the body casting, Fig. 17.
To check M2, hold open t he shutter at the bulb setting and disengage the M1 ar mature as previously described. Re member, pu shing the M1 armature away
from its core opens sw itch S7. S7 must be
open in order for transistor T13, Fig. 14, to turn on.
Now sh ort between the collector and the emitter of T5, Fig. 15. Y ou sh ould see the armature j ump toward the f ront of the camera. If the armatur e jumps away fro m the co re, bo th M2 and C5 must be good.
You might then suspect transistors T5 and T13, Fig. 14. While still holdin g open the shutt er on bulb w ith S7 open, try shorting betw een ground and the collec tor of T13, Fig. 15. Once again you should see the M2 armature jum p away from its core. But, if the arma ture fails to move, trans istor T5 must be defective.
If the armature does move, the pro blem may be with T13 or with the signal from the apert ure-control comparator. You can make one more shor ting test to check T13. Again hold o pen the shutter on bulb and open S7. Then short between the base of T13 and gro und. If the armature jumps away from the core, th ere's no pro blem with T13. The problem must be in the aperture-control circuit. You'll have to remove the to p cover to reach the IC that provides the turn-on signal.
Let's now consid er the other p ossibility
— the M2 a rmature does not release
when you short across transistor T5. You
might first suspect an op en coil. T o check
the coil continuity, measure the resis
tance between th e brown wire, Fig. 15,
and ground. You should measure the
resistance of the coil — around 15 ohms.
Also suspect the diaphr agm-c ont rol
ma gnet M 2 i f the di aphragm fails to stop dow n. Such a malfu nction could indi cate
a problem eithe r with the diaphragm-
control magnet or with the circuit. B ut it's usually fairly easy to pinpoint the probl em area — just check th e operatio n at the d if ferent modes. If the diaphragm fails to stop down a t all three modes — A, M, and S — suspect the dia phragm- control magnet M2. Howe ver, if the p roblem only occurs at the S mode, suspect the c ircuit.
When the diaphragm fails to stop
down, the diaphragm-control magn et
isn’t holding its armature. The armatu re
then immediately arrests the the
dia phragm-c losing lever. If the problem occurs at all three modes, try cleani ng the contact surfaces o f the arm ature and of the permanent magne t, Fig. 17. Dirt can prevent t he core from magnet ically hold ing the armature.
If cleaning doesn't do the job, the pe r manent magnet may be defe ctive. Try pushin g the armat ure of M2 awa y from
the core. Fig. 17; you should be able to feel the magnetic attraction. A defe ctive
per manent magnet requ ires that you replace M2, a job which means pulling the
fron t-plate/mirror-cage a ssembly.
Now consider the othe r po ssibility — the problem only occurs at the S mode. The symptom indicates that the diaphragm- control circuit gets the release signal as
soon as switch S7 opens. You can spo t the
problem by using the technique we describ ed earlier at the bulb setting. Watch the ar mature of M2 as you push the M1 armature
toward the front of the camera, Fig. 16. If the M2 armature now jumps away from the core, the circu it is sending the release signal right away.
To verify the m alfun ction, you might try operating the camera at the S mode while you're shorting across the base and emit ter of transis tor T13 , Fig. 15. You r short should keep transistor T13 shut off. And, as a result, the armature of M 2 should remain against the core. If the ar mature still jumps away from its core, the problem is on the cir cuit board at the bot tom of t he camera — most likely, a shorted transistor. But if the armature re mains against the core, the p roblem is in the circuit that sends the signal to T13. You m ust then remov e the fr ont-plate/ mirror- cage assembly. The p roblem cou ld be as simple as t he violet wire's shorting to ground; or a switch or IC may be defectiv e.
SUMMARY OF TROUBLESHOOTING AT BOTT OM OF CAMERA
As you can see, it's possible t o check most of the electromagnetic diaphra gm- closing and release systems from the bottom of the ca mera. What if the possi bilities we've discus sed don't get you to the problem? You'll th en have to go fur ther. For example, if the mirror won't release electromagnetically, the problem could be in the release swi tch. Yo u can check the remaining switches just by removing the to p cove r. The followin g char t summarizes the troubleshooting cove red so far.
SYMPTOM
Shutter won' t release, LEDs do not operate
Shutter won't release, LEDs operate
Diaphragm fails t o stop down, LEDs operate
All modes
S mode only
Dia phragm always stops down fu lly, "over" LED remains on
POSSIBLE CAUSE
No battery power to lower circuit bo ard
— check for 3V at red wire, Fig. 13. No
voltage — check battery c ompart.
Release swit ch (remove top cover to check)
Coil M1 open Capaci tor C6
Transistor T6
Switch SI, p oor contact Solder connections to lower c ircuit
board (red, black, yellow) No release signal from comparator
Combination magnet M2, arm ature dirty or permanent magnet defe ctive
Vi olet wire shorted to ground Transistor T13
Compara tor always presents release
signal to T13
Solder connections to lower circuit board (purpl e, whit e brown, black)
Film-speed resis tor open (remove top
cov er to check)
IC1 - DIAPH RA GM
CONTROL
PHOTOCELL
AMPLIFIER
SPEED
CONTROL
DI A PH RAGM CONTR OL
IC2 - SHUTTER-
DRIVER
RE LEAS E LOCK
FOR LED s
OU TPUT
LIGHT LEVEL + FI LM SPEED
Figure 18 Actual schematic
Figure 19
ACTUAL CIRCUIT FOR THE COMBINATION MAGNETS
Fig. 18 shows th e actual circuit for the co mbin ation magnets M1 and M2. The two IC's which drive the swit ching tran sistors mount to the flex circuit ins ide the camera. No tice in Fig. 18 that a com parator output of IC1 controls the poten tial on the emitter of T13; sw itch S7 con nects to th e T13 base (in the partial
schem atic s used earlier for ex planatio n, we show ed the comp arator cont rollin g the base of T13).
With S7 closed, the base of T13 con nects to ground. Opening S7 th en con nects the base of T13 to a po sitiv e voltage
— around 1.3V, measured at the w hite wire, Fig. 18. T13 no w has the voltag e it needs at the base. However, the tran sistor can't turn on until the emitter voltage goes less pos itive than t he base volt age.
The c om par ato r inside IC1, Fig. 18,
decides when it's time to turn on T13. IC1
actually makes its ex posure calcula tion as
the diaphra gm sto ps down. At the "S "
mode, IC1 compares the selected shutter- speed set ting at one inpu t with the light level and the film-speed setting at the other input. To stop the diaphragm at the proper f/stop, the comparator inside IC1 switche s low. The emitter of T13 now goes less positive th an the base. As a resul t, T13 turns on and allows C5 to discharge through the coil of M2.
Yo u can see h ow the comparator
makes its f/st op calculatio n in Fig. 19.
The sh utter-speed setti ng provides the in
put voltag e to one input of the com parator; the combina tion of the film-
speed setting and the photocell out put provides the volt age at the ot her input. If in put #1 in Fig. 19 is less positive than in put #2, the c om parator output remain s high to keep T13 turned off.
However, as the diaphragm stops dow n, the output of the photocell decreases. The voltage at input #2 then goes less positive. When the two inpu ts see the same voltage, the comparator knows that the diaphragm has reached the proper f/stop. N ow the comparator switches states — its out put swit ches low
and turns on T13.
Earlier, we mentio ned that S7 must open before T13 can conduct. If S7 re main s closed, the base of T13 stays at
ground potential. Remember, S7 opens when th e mirror -release combinatio n
magnet M1 repels its arma ture. Opening
S7 both applies the base bias to T13 and
disconn ects IC2 from grou nd.
IC2 serves as the driver for the LEDs. So, when S7 breaks the IC2 g round con ne ction, th e viewfinder LEDs turn off . Also, IC2 p rovides the shutter-r elease loc k for the mirr or-release combination magnet M1, Fig. 18. If the batter y vo ltage drops too low, the compara tor inside IC2
won't swit ch on transistor T6. As a result,
the mirror-release combination magnet can't release the mirror.
VARIATIONS IN THE LOWER CIRCUIT BOARD
As mentio ned pre viously, the lower cir cuit board. Fig. 20, comes as a complete unit. Alt hough w e des cribe d techniques for checking the individual compon ent s, you ca n test the complete cir cuits with one shot — just sho rt th e bases of the control transistors to ground.
Check the diaphragm-co ntrol c ircuit by
holding open the shu tter on bulb. Then
push the armature away from the core of
M1, Fig. 20, to open S7 Now short the base
of T13 (the violet or purple wire, Fig. 201 to
the camera body. You should see the ar
mature of M2 jump away from the core.
If shorting th e violet wire to gr ound
causes M2 to repel its armature, all of the
diaph ragm-control circ uit on the bottom of the camera must be worki ng. What if M2 doe sn't repel its arma ture in n ormal operation? Apparently the comparator in side IC1 isn’t switching low to provid e the emitte r bias for T13.
Similarly, you should be able to make
the mirror-release magnet M 1 repel its ar mature by shorting the yellow wire to ground (the yellow wire that c onnects to
the base of T6, Fig. 20). Shorting the yellow wire to groun d should turn on T6. If M1 repels its armature and releases the
mirror, the mirror-r elease co mp onents must be good.
If you find that there's a problem on the lower circui t board, however, you may run into a parts snag — there are two dif
fere nt versions of the board, and th e two typ es won't alway s interchange. Fig. 21 shows the early version of th e board; Fig. 22 shows the modified version.
Whether or not you can install the later
version in an earlier camera depends on the flex circuit. You must then identify the flex circuit. Alte rnately, you may have to replace the compl ete flex circuit and the l ower cir cuit board as a unit. You'll be able to ident ify the flex circuit after you remove the top cover.
REMOV ING THE TOP COVER
Unscr ew the wind- lever retaining
screw. Then disconnect the end of the wind-lever return spring, Fig. 23, as you
lift off the wind lever. Also uns crew the top-cove r retaining ring around the wind shaft. Fig. 24.
Next unscr ew t he re taining ring that
holds the speed knob. Fig. 24. Although
we us ed the bulb setting as a reference in
Fig. 24, the actual shutt er-spee d and film- speed setting s aren't important for disassembly. Remove the speed knob and not e the loose release pin. The release pin closes the switches for the met ering and release functions.
You ca n completely remove the camera back by depressing the hing e pin. Then unscr ew the rewind knob. Remove the film-speed dial b y unscrewing its retaining ring and take out the parts indicate d in
Fig. 25 — the d etent plate, the black plastic decora tor ring, the brass bushing, and the expos ure-compensat ion lever.
Finally, remove the top-cover screws. Two of the top-cover screws also hold the diaph ragm -window plate, Fig. 26. If you wish, you can remove the front decorator
plate. Fig. 26, after you take off the diaphragm-w indow plate. However, unless you know you're going t o remove the fron t- plate /mirror-cage assembly, you can leave the front decorator plate installed.
Before lifting of f the t op cover, push down the eyepiece-blind lever, Fig. 27. The eyepiece bli nd then covers the eyelens. This precaution prevents the other end of the eyepiece-blind lever f rom catching the flex circuit as you lift off t he top cover.
Figure 21 Early style board
Figure 22 Modified board
B LACK PURPLE OR VIOLE T
REPLACING THE TOP COVER
When you replace the top cover, the mo de selec tor, Fig. 24, must key to the mo de switch, Fig. 28. Fig. 28 shows the mo de switch set for manual shutter
speeds — the "M " position. To set autom atic shutter spee ds, move the
mo de switch t o the center p osit ion; move the mod e switch all the way in a counterclockw ise direction to set automatic d iaphragm openings.
Normally, you'll fin d that the mode selecto r keys most easily at the "S" set tin g. Set the mode selector in the top cov er t o "S ." Then turn the mode switch. Fig. 28, all the way in a count erclockwise dir ection. After seating the to p cover, check t o see that the viewfinder scale switche s from the diaphragm calibrations to the shutter-speed calibrations when you m ove the mode selector to "A .”
Also, with the top cover remov ed, the film-a dvance indic ator, Fig. 28, ten ds to sneak under the counter dial. Tightening the retaining ring around the wind shaft.
Fig. 24, then binds both the counter dial
and the film-adva nce indicator.
The film-advance indicator only moves when there's film in the camera. As the
film winds onto the take-up spool, it pushes forward a lever inside the take-up cha mber. The lever then moves the fil m- advance in dicator from left to right in Fig.
28. You can see the film -advance in dicator throu gh the window at the back of the top cover.
Check the film-advance ind icat or after you replace the retaining ring around the wi nd shaft. Fig. 24. Reach t o the front of the take-up spool and push forward the lever that extends i nto the take-up chambe r; the film- ad vance indicator
should mo ve in to the window. If the film- advance indicato r doesn't move, loosen
the retain ing ring. Fig. 24. Then hold for ward th e lever inside the take-up chamber so that you can see th e film-ad vance in dicator within its w indow. Continue hol ding the lever as you tighten the re
taining ring.
To replace the wind lever, first hook its
hole to the end o f the wind- lever ret urn
spri ng. Then rotat e the wind lever in a
co unterclo ckwise direction as yo u seat it over the wind shaft. The upper coil of the
SP E E D K N O B RE T A IN I N G R I NG
wind lever re turn spring sometimes
sneaks under the wind lever. If tha t hap pens, the wind lever won't return freely
after you replace t he cover screw.
The film-speed dial can also be tric ky to install. Replace the exposure-co mpensation lever and the deten t rack as shown in Fig. 29; notice that the slot in the exposure- compen sation lever fits over the tab on the film-speed resistor ring. Then replace the black plastic d ecorator ring. Fig. 25. The notch in the decorator ring goes under the exposure-compensation lever.
TO P C O V E R RE T AI N IN G R IN G
EX P O S U R E C O M P E N S A T I O N LEVER /
DE C O R A T O R RIN G
EYE P IE C E- BL I ND L EVER
DET E NT PLATE
UP P E R BR A S S BU S H I N G
Figure 24
FRO NT - DE C O R A T O R PLA TE v
Figure 26
MO D E S E L EC T O R
LON G T O P - C O V E R SC R E W S I
mmo
Figure
TO P -C O V E R SC R E W
-----
MO D E S W I T C H IN M M O D E
A M O D E
Figure 29
TAB ON RESIS TOR RING
SPRING ON EXPOSUR E-CO MPENSATION LEVER
Ne xt seat th e upper brass bushing. Fig.
25. Two tabs on the underside of the up per bra ss bushin g fit into the two slots of the lower brass bushing. Fig. 29. Also,
the ends of the spring attached to the expos ure -comp ens ation lever, Fig. 29, must come against t he outer cir cum
ference of the upper brass bushing.
Finally, seat the film -speed dial wi th its
slot over the tab on the film-speed brush.
Fig. 30. Replace the b lack pla te (the plate with the compensation calibrations) so that the film-speed window is over the film-speed cali brat ions. Then rota te the
black pla te u nti l you feel its tab drop into
one of t he slot s in the upper brass
bushing .
CHECKING THE FILM-SPEED
RESISTOR
With the top cover removed, you can
see the parts of the film-speed resistor.
Fig. 31. If you know you're going to remove the front-plate/m irr o r-cage assembly, lift out the f ilm-speed lock, the lower brass bush ing, and the film-speed brush. How ever, if you're trouble shootin g or adjusting the camera, reassemble the film-speed dial.
Why? With the film-speed dial remov ed, the film-speed brush doesn' t make firm contact with the resistor rin g, Fig.
31. T he camera then exhibits the symp toms of an open film-speed resistor:
Figure 31
- only the overrange LED turns on
- the diaphragm always stop s down fully in the S mode
-th e shutter de livers only th e
mechanical speed ( 1/1000 second) in either automatic mode.
Even wit h the film -speed dial reas sembled, there's a trick to setting t he film speed. With the top cover removed,
neithe r t he film-speed lock no r the exposure-compensation lever keys t o anything. You must s et both part s in their
pro per positions before th e film-speed
setting is valid.
A detent spring on t he bottom of the resistor ri ng prov ides the click stops for the compensation settings. The detent spring catches one of five detent slots in the rewind-shaft suppor t plate. Fig. 31. First turn the exposure-compensa tion lever until the deten t spring seats in the center slot; that's the "no rmal" position. The two slots on each side of the "no rmal" position provide the intentional overexposure and undere xposure setting s.
Next rotate the film-sp eed lock to align the "0" com pensation calibra tion with the index on the compensa tion lever. As lon g as the "0 " calibration remains a lign-
ed, you can believe the film-speed set
ting. Naturally, Minolta has a spe cial top cover whic h holds the film-spe ed dial in position for test s and adju stmen ts (ASA
100, 0 co mpensation). But, without the special top cover, you'll have to make sure the parts don't shift out of position.
Fig. 32 illustrates the ope ration o f the film-spe ed resistor. Se tting the film speed moves t he film-speed brush along the resistance band; chan ging the com pensa tio n setting ro tates the resistor ring. In
either case, you're changing the resis
tance be tween th e blue wire and t he gray
wi re to program the operational amplifier
inside IC1.
If you measure the resistance between
the purpl e wire and th e gray wire, Fig. 32, you should read the value of the entire
resistance b and — arou nd 28K. Betwe en
the b lue wir e and the gray wire, you should see the resistance smoothly decrease as you set slower film speeds; the resistanc e sh ould g o from arou nd 28K to around 847 ohms . Here are the re sistance values measured from a repre sentat ive camera for differen t compe nsa tion settings at ASA 100:
tact at the left-hand side of the brush.
Fig. 33, causes the overrange LED to re main on. Also, the shutter delivers only its mech anical speed. Poor contact at the right-ha nd side causes the shutter to hang open at all modes.
Later models of the camera have a sup port arm above the mode switch; the sup port arm maintains firm brush contact .
FILM-SPEED BR USH
^V W V W W V A
Figure 32
But, in earlier models, the mode switch should be on e of your first suspects . You can pinpoin t a problem to the mode switch by using volt age tests . However, you m ight first repla ce the speed knob and the win d lever. You’ll the n be able to
troubleshoot most of the electronics in
the camera — even though you can't as yet reach all of the actua l components.
PURPLE
BLUE
GRAY
+ 1
0
-1
5.84K
9.06K
12.55K
CHE CKING THE MODE SWITCH
Bef ore replacing the speed knob, you
might take a look at th e speed selector and the mode switc h at the win d-lever end of the camera. Fig. 33. At the "A ” se tting, the nut on the mo de s witch
comes against the mask lever. The nut
then pushes the mask lever in a clockwise direc tion. In tu rn, the mask lever pulls the
mask over the windo w for the shutter- speed indication. Remember, the shutter- speed s etting has no meaning in the "A" mode.
The spring-lo aded scale to the front of the pentaprism provides the shutter- speed indic ation. Fig. 34. A tun gsten wire couples the shut ter-speed scale to the speed selector. T urnin g the speed selec tor in a counterclockwise direction draws the tungsten wire from l eft to right in Fig.
34. The tungsten wire then pulls the shutte r-sp eed scale to th e faster- speed cali brat ions. Not ice that you can rotate the wire-hooking nut. Fig. 33, to precisely ali gn the shutter-speed calibrations through the finder.
Certain malfunctions in the electro nic operation might lead you to suspect a
pro blem with the mode switch. For exam ple, suppose that there 's poor brush con
tact or dirty contact surfaces. Poor con
Figure 33
Figure 34
OPE RATION OF THE METERING SYSTEM
From the l op of the camera, Fig. 34, you can see only one of the three IC's — IC1. The other two IC's moun t to the flex circuit at the side of the mir ror cage. IC2, as mentioned earlier, controls the viewfinder LEDs. A hybrid IC — H-IC — contai ns the tran sistor swi tching system that links together the various camera funct ions.
But IC1 does just about eve ryth ing else in the camera. For one thing, it contains the o p amp for the single silicon photo diode (SPD) , Fig. 35. Pushing the release button part way c loses the metering switch to supply power to the circuit ; you
should then measure +3V at pin 1 of IC1,
Fig. 34. Also, the circuit forward biases the silicon photodiode.
Figure 35
SP EED
A AND S MODES
Figure 36
Curren t through the S PD determines the gate bias of an FET (field-effect tran sistor), Fig. 36. You can't as yet see the FET in the camera; i t mou nts t o the underside o f the flex circu it. The FET then changes the linear current changes through the SPD to li near voltage
changes at the amplifier input.
The voltage at the output of the op
amp . Fig. 36, now goes more positive as
the light intensity increases. This voltage
output feeds two circuits — th e memory system through IC1 and the LED display through IC2. Besides seeing the output of the op amp, IC2 receives an input from the diaphragm resistor, Fig. 36. Conse quentl y, all three exposure variables —
the light level, the fi lm speed, and the f/stop — contrib ute t o the LED readout. At the "S " mode, the m inimum-aperture
COMPARATORS FOR LEDS
DIA PH RAG M RESISTOR
— V ^ A A
(0
uj O t o »
ir uj
= UiW
z a uj
to tone
MEMORY SWITCH
MEMORY CAPA CITOR
information also goes to IC2.
IC1 uses the op amp output to charge the memory capacitor , Fig. 35. A s the output of the op amp g oes more pos itive, the voltage measured across the memory capacitor increases. So, if you connect a voltmeter across the memory capa citor, you shou ld get a higher reading as you in crease the light level or set a faster film speed. Ju st push the release button part
way to charge the memory capacitor.
The charge acro ss the memory ca pa ci tor can continu e changing as long as the memory switch. Fig. 36, rem ains clos ed. Fig. 33 points out the memory swit ch in the camera. Just before the mirror
starts to rise, the insulated lever shown in
Fig. 33 drives open the m emory swi tch. Opening the memory swit ch locks in the memory-capacitor charge .
However, you' ll notice in Fig. 36 that the memory-capacitor charge doesn't change with differ ent diaphragm open ings. The diaphragm resistor affects only the meter readout; it has nothing to say ab out the actu al expo sure time. Yet the expos ure -co ntrol circuit m ust k no w the diaphragm s etting in order to program th e proper shut ter speed.
Unl ike most systems, th e XD-11 selects the automatic shutter speed by reading the light through a stopped -dow n ap er ture. With the diaphragm fully open, the SPD sees the maximum amount of light. The indication c ircuit for the LED readout mu st know the selected diap hragm open ing in o rde r to display the p roper shut ter speed at the " A " mo de.
Then, when you push the release but ton the rest of the way, the di aphr agm sta rts closing. As a result, the SPD sees less and less light. Now the volt age out put of the op amp decreases (goes less positive) in proportion to the actua l dia phragm opening.
The vo ltage ac ross the memory capacitor also decreases as the d ia phragm s tops down. Once th e diaphragm reaches the prop er aperture size, the me mor y switch opens. Consequently, the charge remains locked in the memory capacito r. The mem ory-capa cito r voltage, modified by the decreasing ou t put of the op amp, re flects all of the ex posure variables — the light level, the film-speed se ttin g, and the diaphragm opening.
After the memo ry switch opens, the mi rror starts mo ving to the takin g posi tion. The output of the op amp then drops even more. Bu t the actual metering voltag e no longer matters — the m emory capacitor has already memoriz ed the
reference voltage.
The unique metering action can help in tro ubleshooting. Since the indication cir-
cuit takes its l ight reading thro ugh th e
largest ap erture — and the exposure-
control circuit takes its ligh t reading
through the stoppe d-d own aper ture — the two systems can disagree. For example,
suppose there’s a problem wit h the
diaphragm resistor. Al though the LED in dication would then be incorrect, the shut ter would still provid e the proper exposure.
You can get a better idea of the two
separate actions if you operate the
camera on "A " with the lens rem oved. Try rotat ing the diaph ragm-metering ring
un til the LED display indicates a slow
shutt er speed. Then release the shutter.
You'll find that th e shutter delivers an ex
posure time that's much faster than the
readout indicates. Why? You tricked the
readout int o thinking you'd set a small ape rture. But the exposure-control circ uit
knew better.
At the manually calibra ted settings, the meter readout still tells yo u the proper shutt er speed for the light conditio ns. However, the shutte r-speed setting — rather than the op amp — controls t he voltage across th e memory capacitor. As you set faster shutter speeds, the v oltage across the memory capacitor increases.
Earlier, we mentioned the symptom when there's poor contact at one side of
the m ode switch — the s hut ter hangs
open at all functions. You can see why in Fig. 36. If the mode switch fails to make good contact, the me mor y capacitor
ycan't charge. Then, since the shut ter
thinks you' re shooting in total darkn ess, it hangs open.
A d efective memory capacitor or poor cont ac t in the m em ory switch, Fig. 36, results in the same malfu nction. In fact,
any condition whi ch prevents a reference
volt age causes the shutter to hang open.
The block diagram of the shutter-speed
control circuit, Fig. 37, may make the reason appare nt.
The me morized voltage across the memory capacitor provi des the base bias for the current-control transis tor, Fig. 37.
Cur rent t hrough the t ransistor cha rges
the timing capacitor. With a larger (more
positive) base volt age, the transis tor con ducts harder; it then charges the timing capacito r more quickly.
Howev er, if there's no voltage ac ross the m emory c apacitor, th e transistor won't conduct at all. As a resu lt, t he tim ing cap aci tor never reaches the voltage which shuts off the electrom agnet cur rent. And the shutter stays ope n.
Fig. 37 also sh ows the elec tromagnet current path. Consider that you' ve just completed the release-button stroke to release the shutter. As you' ve seen, switch S7 remains closed until the mirror- release combination magnet M2 repels its
armature. Wi th S7 closed, the sw itching transisto r. Fig. 37, turns off; the base of the tr ansisto r connec ts to grou nd.
With the swit ching transisto r turned off, OV appears at each lead of the elec tromagnet. Then , when th e mir ror re leases, S7 opens and applies a positive voltage to the transistor base. The swit ch ing transis tor now turns on, connec tin g the red electromagnet lead to + 3V.
The holdi ng current flows from the electromag net current source, Fig. 37, through the coil, and through the tran
sistor to the positive side of the supply.
Now the energized electromagnet holds the closing blade to keep the shutter open. The current source continues
feeding cur rent to the electromagnet until the timing capacito r charges.
Figure 37
Figure 38
But the timing capacito r can t start charging until the trig ger swit ch (ti ming switch) open s. Fig. 37. As long as the trigge r switch r em ains closed, th e cu rrent-control transistor won't condu ct. The trigger switch c loses whe n you cock the shutter. Then, when the opening-
blade assembly st arts to move, it opens
the trigger switc h.
Now the expansion circuit feeds cu r
rent to the em itter of the current-control tra nsistor. Fig. 37. And the tr ansistor turns on, conducting t he current that charges the timing capacitor. The higher the memorized reference voltage, the mo re quickly the timing capacitor reaches the vo ltage which shuts off the elec
tromagnet current source.
Fig. 38 shows the voltage measured
3V
acros s the t iming ca pacitor. When you
push the release button far e nough to close the metering switch, a slight voltage appears across the timing capacitor. However, the timing capacitor can't charge any further until the trigger swit ch open s. Openi ng the trigger switc h then all ow s the timing capacitor to charge as shown in Fig. 38. When the timing capacitor reaches around 0.5V, it s huts off the current thr ough t he electromagnet to end the exposure.
You can 't as yet reach mo st of th e
components shown in Fig. 36 and Fig. 37.
But you can often pinpoin t the problem from t he top of the camera. So, before covering the complete electro nic opera tion, let's run through the techniques you
can use to check the switches and the elect romagnet without disassembly.
CHECKING THE ELEC TROMAGNET
An o pen electromagn et coil causes the shut ter to deliver only its m echanical speed (1/1000 second o r faster). Al though you'll have to re move the Seiko shutter to replace t he electromagnet, you can c heck the c oil without fu rther dis assembly. Remove the small section o f in sulating tape at the top of the f lex ci rcuit. You can now see the bro wn wire and the
red wire coming from th e electroma gnet.
Check the con tinu ity of the coil by
measuring the resistance between the red
wire and the bro wn wire. You should
measure aro und 300 ohms. Alternately,
you can perf orm a quick sh orting t est to
determine if the electromagnet is good. Try sh orting between the brown wire and ground as you release the shutter. If the
coil is good , the shutter wi ll hang ope n for as long as you maintain the short.
With most electronic shutters, you can check coil continu ity by measuring the voltage a t each electromagnet lead. If you
Figure 39
measu re a volta ge at one lead but not a t the other, the coil must be open. However, y ou've seen that the transistor in series with the XD-11 electromag net re mains off until you release the shutter. So, at the red electromag net lead, you'll measure 0V — not the full battery voltage as you would with most other circuits. You'll also measure 0V at the brown lead.
When you release the shutter, the tran sistor turns on and co nnects the red elec tromagnet lead to positive b attery, Fig.
38. So, with the sh utt er open, you should
measure 3V at the red wire, Fig. 39. But you sho uld still measure 0V at th e brown wi re. The brown wire now con nects to 0V, keeping a 3V pote ntial d ifferen ce
acros s the electroma gnet.
The volta ge at the brown wire s witches high to end the exp osure. If you leave the positiv e voltm eter lead on the brown wire, you can see the voltage switch high. You should see a voltage indication at the end of th e exposure. But the voltage only appears brie fly. When t he mirror returns, switch S7, Fig. 38, once again opens to sh ut off t he transistor. Both elec tromagnet leads then return to 0V.
A poor ground c onnection in t he circuit may also cause the shutter to deliver only its f astest speed. Suspect a poor ground connection if you measure a voltage at the red el ect romag net lead whe n you par tially depress the release button. If you
measure around 2.5V, try retouching the sold er connections to the black ground
wire, Fig . 39. How ever, you may have to
remove the f ront-plate/m irror-cage asse mbly to correct the ground contact. A scre w on the section of flex circuit that mounts to th e mir ror cage makes the ground connection through the camera body.
If you measure the full 3V to the red wire
and the brown wire, the switching tran
sistor may be shorted. Fig. 38. A 3V reading could also indic ate a problem with the elec trom agne t current source. Both components are inside H-IC, the hybri d IC on the side of the mirror cage. You'll have to remove the front-p late/mirror-cage
assembly to replace the IC.
CHE CKING THE METERING SWITC H AND THE RELEASE SWITCH
Both the metering switc h and the release switch are a t the back of the front- plate as sembly. A s yet, you can 't reach
the switches. But yo u can reach the switch connections for troubleshooting.
The mete ring switch c onnect s to the green wire, and the release switch con nects to the oran ge wire, Fig. 39.
Fig. 40 s hows the portion of the schematic t hat includ es th e two switches. As you st art pushin g the release button, the m eter ing swit ch S5 closes. The
metering swit ch t urns on transistor T1,
applying the positive battery volta ge to
pin 1 o f IC1 and to pin 2 of IC2.
Pushing the release button the rest o f
the way closes th e release switch S3. The release switch now tells the elect ro magnetic release circuit to release the mir ror. Also, the power-holding circuit —
trans istor T11 in Fig. 40 — turns on. T11
now keeps transistor T1 conducting. So, even if y ou allow the release button to return, the circu it con tinues to operate.
Tra nsistors T1 and T11 are both inside
H-IC on the side of the mirror cage. Diode D2, a transis tor conn ected as a d iode. Fig. 40, is also inside the hybrid IC. You might sus pect a prob lem in this por tion of the circu it if th e camera draws pow er constantly — even though you haven’t depressed the release button.
What if the metering switch S5 fails to
make contac t? Obviously, the LEDs will not turn on when you partia lly depress the release butto n. Yet, thanks to the power-
holding circuit, the LEDs will turn on when you fully depress the release button. With a defective release switch S3, the shutter won't release at the electronically co n trolled settings.
To check the metering switch , measure the vo ltage at the green wire, Fig. 39. You should measure around 2.5V. Wh en you depress the release b ut to n part way, you should measu re 0V at the green wir e. If the voltage doesn't drop to 0V (ground), the me tering sw itch isn't making good contact.
Alternately, you can check th e metering switc h by connecting an ohmmeter be tween the green wire and gr ound ; you should measure direc t conti nuity when you push the release button part way . Or you can simp ly sho rt the green wire to ground. C onnecting the green wire directly
to groun d s hould turn on the LEDs.
If the LEDs turn on during yo ur sho rt ing test, the problem must be in the metering swit ch . However, if the LEDs still won't turn on, the problem is in the cir cuit. Supp ose, for example, that you measure OV to pin 1 of IC1 while you're shorting th e green wire to grou nd. Suspect a problem with H-IC; transistor T1, apparently i sn't turni ng on.
Use similar techniq ues to check th e release sw itc h. But remember — the release switch only closes at the elec tronically control led speeds. Use any speed-knob setting except bulb or the mechanical 1/100 second. Then measure the voltage to th e orange-wire connec tion, Fig. 39. You should measure 2.5V un til y ou fully de press the release button; the voltage sh ould drop to 0V with the
release button depressed.
You can also use a shorting test to check the release switch. Shorting the orange wire
to ground should release the shutter. If your
shorting test doesn't release the shutter, IC2
may be the problem.
CHECKING THE TRIGGE R SWITCH
Like the electro magnet, the trig ger switch is a shut ter part. The trigge r switch should close when y ou cock the shutter. When the shu tte r releases, the trigger switch should open to initiate the exposure.
If the trigge r switch remain s closed, the shutter wi ll hang op en. If the trigger switch fails to close or makes poor con tact, you won't be able to bring in your
shutter-speed adjus tments — e specially the fast speeds. Erratic shutter speeds may also result from poor con tac t in the trigger switch.
The trigg er switc h connects between the black wire. Fig. 39, and ground. Check the c ontinuity b etween the black wire and ground with the shutter cocked; you should measure direct continuity, in dica ting tha t the trigg er switch is closed.
Then release the shutter. You should now
measure no cont inuity — an open — be tween the black wire and ground.
CHECKING THE MEMORY S WITCH
Poor co nta ct in the memory switch n or
mally causes the shu tter to hang open.
With most cameras, you must perform
major surgery to reach the memory switch.
But, in the XD-11, you need only remove the top cover to clean the memory switch and ch eck the contin uity .
The blade of the memory switc h that's closer to t he back of the camera connects to the memory capacitor and t o pin 10 of IC1, Fig. 34. You can check the memory switch by measuring the volta ge to pin 10 with the release button partially depress ed; you should measure around 0.5 V. If the memory switch is n't making good cont act, you'll measure 0V at pin 10.
Or you can measu re the cont inuity be tween the front blade of the me mory switch, Fig. 33, a nd the memory ca
pacitor, Fig. 35. You should measure
direct co ntinuity. With the shutter held
open on bulb, you should measure no continuit y.
Figure 40
minolia :xe>ii
1- ■ — -----
SCHEMATIC OF THE XD-11
It may at first appear that the complete sche mat ic. Fig. 41, shows only two of the thr ee IC's. Howev er, t he circled num bers ind icat e the connections to th e third IC — that ’s H-IC, t he hybrid IC on the side of th e mirror cage. All the parts enclosed by the dotted line are inside H-IC.
The schematic shows all the components insid e H-IC. It also gives you a good indication as to the compone nts inside the other two IC's. Such detailed in formation can be especially helpful in t roubleshooting. N o, you can't ta ke apart an IC to repair the innards. But you can tell wha t k inds of signals should appe ar at the IC pins.
For exam ple, the large triangle inside IC1 ind icates the ampli fier for the silicon photocell (SPC in the schematic). The connection at pin 19 charges the memory ca pacitor C2. You then know a t a gla nce th at the vo ltage at pin 19 sh ould go more positiv e as you increase t he light striking the SPC .
The center triangle inside IC1 is the c omparator for the diaphra gm-con trol circu it. Wh en the output of the comparator switches low, it turn s on transistor T13. T13 th en switche s on T5. Now C5 discharges through the diaph ragm-c on trol ma gnet M2 to arrest the diaphragm closure.
At pin 16 of IC1, another comp arator provide s the switch fo r the closing-curtain electromagnet M3. When the comparator output at pin 16 dro ps low , current flows throu gh M3 to hold
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open the shu tter. The v oltage at pin 16 goes high to shut off the electromagnet curr ent.
Inside IC2, you ca n see the large triangl e which represents the individual comparator stages for the LEDs. The catho de of each LED connects to a comparator output. N otice that the anodes of the LEDs con nect to ■+ 3V when t ransistor T1 turns on. Each LED then has the an ode bias it needs to conduct. As soo n as the cathode of a particular LED swit ches low, curr ent can flow through t ha t LED.
The small comparator inside IC2 — the one connected to pin 3 — provid es the release loc k. Whe n the release switch S3 closes, the comparator compares the battery voltage with a reference voltage. Then, providing there's suffic ient power for proper o peration, the c omparator swi tches lo w. The low voltag e at pin 3 forw ard biases transistor T6 to release the mir ror. Anoth er triangle in side IC2 rep resent s the ana log-to -digital converter which ligh ts the "60" LED when the flash unit charges.
As yet, you can only reach one IC for voltag e tests — IC1 at the top of the camera. However, you'll be able to check H-IC after you rem ove the front-plate/mirror-c age as sembly. So, before go ing through the rest of the electronic operat ion, we'll describe the procedure for separating the front-plate/mirror- cage assembly from the body casting .
Figure 41
REM OVING THE FRONT-PLATE/ MIRROR-CAGE ASSEMBLY
As mention ed earlier, the front plate, mirror cage, shutter, and flex circ uit come out as a unit. What's more, you don't have to uns older a single wire. If you haven't already done so, remove the fron t de corator plate; a slit a t the top, Fig. 42,
Figure 42
allows you to slightly spread the s ides o f the f ront d ecorator plate to clear the lens- mount ing ring . T he stop-down b ut to n at the side of t he front-decorator plate will be loose.
The sm all plate you can now see at the side of the lens mount. Fig. 43, c overs the air -da mp ing piston; the plate simply clips
into place. In ac tion, the air-damping piston slows d own the upward mo ve ment of the mirror; that gives the diaphrag m time to sto p down. Then, afte r the diaphragm has reached the proper f/stop, the mirror me chan ism ope ns the me mory switch.
Now remove the re wind-shaf t s upport plate. Fig. 42, by taking out its three screws. Then peel off t he re wind-side front leath erette. To completely remove the wind-s ide fron t leath erette, you must take off the self-timer lever. Ho wever, you need only peel back the leatherette fa r enough to reach the two front- plate screws.
At the bot tom of the camera, remove
the screw holding the reset switc h S1. Lift aside the S1 assembly wit h the two yellow wires still attac hed. Als o lif t aside the battery compartment a fter taking out its two screws. Then re move the two scre ws holding the lower circuit board.
Finally take out the four front-plate screws. Not ice the position of the one slotted screw — the locating screw in the
upper wind-side corner. You can now separ ate the front- plate/mirror-cage asse mbly from the body casti ng, Fig. 44.
Before rep lacing the assembly, charge
both the shutter and the mirr or cage. Charge the shu tte r by pus hing the shut ter-cocking lever from right to left in
Fig. 44. T hen c harge the mirror by pushing the mirror-tensioning lever from left to rig ht, Fig. 44.
Figure 43
Figure 44
SHUTTER-COCKING LEVER
MIRROR-TENSIONING LEVER
OP ERATING THE FRONT-PLATE / MIRROR-CAGE ASSEMBLY
You can still oper ate the assembly at
the me chanical sett ings. Set th e speed knob to eithe r "0 " or "B ." Then push the release button to release the mirror.
At the m echanical settings, the release-
slide latch, Fig. 45, move s away from a
notch in the release slide. Now th e release
slide can move down its full distance and
release the mirror. However, when you select an electronically contr olled speed, the release-slide latch sw ings under the
release-slide notc h as show n in Fig. 46.
Here, the release-slide latch prevents the
release slide from movin g down far enough to me chanically release th e mirror.
So, to release the mirror electronically, you'll have to connect a 3V power supply to the c irc uit. Connect the p ositive power-suppl y lead to the battery- compartment terminal; connect the neg ative pow er- supply lead to any metal portion of the fr ont plate.
There's on e more connection you must make. Normally, the lower c ircuit board makes its grou nd conn ection through the bod y casting. But now, with the lo wer cir
cuit board removed, you must provide the
ground. Connect a jumper between the
ground land on the lower circuit board, Fig. 47, and the front plate. The shutter should then operate electronically.
Connecting the power supply also allows y ou to check the voltages to H-IC, Fig. 48. Th e two variable resistors you can see in Fig. 48 pr ovide the adju stments
for the LED readout. However, you should avoid disturbing these ad
justme nts. Why? Because you mus t
remov e the front-plate/m irr or-cage assembly to reach the variable resistors.
The Minolta service manual do es
describe a special tool for adjust ing the
LED readout — a dummy camera body
which has a special cutout over the
variable resistors. But, according to Min olta, the dummy camera body isn't
available. You can't even make your own
by purchasing a replacement body casting; the body casting is the one part in the
XD-11 which Minolta doesn’t supply.
An XD-11 that's beyond ec onomical repair may then be worth pu rchasing; you can use the bod y cas ting to make the special tool. But, in most situations, you
won't have to adjust the two variable
resistors a nyway. If the ot her adjustments
are correct, the LED readout should also
be correct. We'll describe the adjustment sequence a litt le later. For n ow, just rememb er to avoid dis turbing the two variable resis tors on the side of the mirror cage.
Figure 45 Mechanical setting
Figure 47 Ground jumper connected
Figure 46 Electronic setting
Figure 48
CHECKING H-IC
You mig ht suspect H-IC, Fig. 48, if nothi ng works electronically — the LEDs won't turn on and th e shutter won't release. Also susp ect H-IC if you're get tin g battery d rain withou t d epressing the release button part way. The customer then complains that the batteries don' t last.
H-IC supplies the powe r to th e other two IC's. When you push the release but ton far enough t o close t he meterin g switch S5, transistor T1 tur ns on, Fig. 49. The +3V signal then appears at pin 6 of H-IC, the coll ect or of T1.
So, with t he release button partially
depressed , you should measure close to
3V at pin 6 of H-IC (actually, the power- suppl y voltage minus the drop across T1). You should also measu re 3V at pin 1 of
IC1, Fig. 50.
If you don't get the 3V signal at p in 6 of H-IC, chec k the voltage at pin 5. Notice in Fig. 49 that pin 5 c onnects d irectly to the
positive side of the supply. Consequ ently , you should mea sure the full power-sup ply voltage at pin 5 — even with out depress ing the release button. If not, check the battery connecti ons and the pink w ire th at runs from the low er circuit board to pin 5 of H-IC, Fig. 48.
Notice in Fig. 49 that the full power-
supply voltage always appears at the two release capacitors — C5 for the diaphragm- control system and C6 for the mirror-release system. You should then measure 3V across each capacitor regardless of the release-button position. The power-supply voltage also co nnects d irectly to the emitter of T12, the transistor in series with the shut ter's electromagnet.
However, at the collector of T12 — pin
10 of H-IC — you should measure 0V.
The voltage at pin 10 should switch to
nearly 3V with the shutter open. Tran
sistor T12 then turns on, conducting c ur
rent through the c oil of M3.
Fig. 51 shows t he rema ining pin volt ages of H-IC. The voltage at pin 7 pro vides the cathode bias for the SPC. This voltage is the sum of the vo ltage drops across two transistors connected as diod es — T2 and T7, Fig. 49. A forward- biased diode provides an ef fec tive voltage reg ulator; its voltage drop remains con stant at around 0.6V, despit e changes in current. So, with two diodes in series, the voltage at pin 7 should remain constant at ap proximately 1.2V. The filter capacitor C1 helps main tain the constan t reference volta ge.
The 1.2V refe rence conn ects to the cat hode of the SPC, Fig. 49 and Fig. 50. Here, the voltage should remain constant
— de spite changes in the light level. But
the voltage at the anode of th e SPC
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Figure 51
sho uld go more positive as the light level increases. The anode voltag e provides the gate bias for the FET, Fig. 49.
In effe ct, the FET takes the linear cur
rent change s throu gh the SPC and con verts them to linear voltage cha nges w hich drive t he amplifier. A silicon phot od iode doe s put out its own voltage.
Bu t the voltage chang es across a silicon diode aren't linear with respec t t o light- level changes; ra ther, the voltage change is the log of the light- level change. The FET th en p erfo rms logarithmic expan sion. Volta ge chang es at the output of
the FET matc h the light-level chang es in
linear fashi on.
The op amp inside IC1 now takes the in
put f rom the FET and pro vides an
amplified outp ut a t pin 19, Fig. 49. Notice that the memory capacitor C2 connects to pin 19 throug h the closed memory switch S6. With the me mory switch closed , the memory capacitor the n charges to the pin 19 vo ltage. The voltage at pin 19 goes more positive as the light level increases.
You sho uld now be able to visualize th e
symptoms which could result from a
Top o f camera
6
H-IC
3 2
4
5
defect in H-IC. Suppose, for example, that t he LEDs don't turn on wh en you depress the release button part way. You
then check the voltage at pin 6 of H-IC. I f you measure 0V at pin 6 — bu t you get 3V at p in 5 — suspect the meter ing switch
S5 and transistor T1 , Fig. 49.
Earlier, we described one way to check the meterin g switch at the top of the camera . You can also check the metering swit ch at H-IC, Fig. 49. Sh ort ing pin 3 to ground sho uld turn on t he LEDs. If so, you k now that H -IC must be o.k.; t he problem must be wit h the metering switch o r t he wiri ng. But, if the LEDs still won't turn on, you 'll probably have to replace H-IC.
We also mentioned ano ther possibility
— the camera constantly dra ws current, causing excessive battery drain. Tr y measuring the volta ge at pin 6 without depressing th e release b utton. If you measu re close to 3V, transistor T1 may have an internal sh ort. Or the power- holding circuit — T11 and D2, Fig. 49 — may be keeping T1 tu rned on. Either way, replace H-IC.
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Figure 52
CONNECT IONS TO THE LED READOUT CIRCUIT
Even with the mir ror cage removed , you can't reach IC2; the driver fo r t he LEDs moun ts to the othe r side of the fle x circuit. Fig. 48. However, you can make most of th e tests without further disassembly.
At the A and M settings , IC2 conside rs four values — the shutter-speed setti ng, the film-speed setting, the diaphra gm set ting, and the light level. It then turns on the appropriate LED to indicate the cor responding shutter speed.
You can follow the connections in Fig.
52. The diaphragm information (AV) ap pears at pin 10 of IC2. At pin 12, IC2 receives the light-level (BV) and film- speed (SV) information . The shutter- speed information (TV) from th e shutter- speed resistor RTV goe s to pin 11.
When you select the S mode, IC2 also
Figure 53
receives the minimum-a perture informa tio n at pin 9. Switch S12 at the f ront of the camera, Fig. 53, selects a resistance value according to the minimum ape rture of the lens. With no lens installed, notice that the S12 brush rests a t the center of the first resistance p ath, Fig. 53. In stalling the f /16 MD lens set to the smallest aper ture moves the brush to the second re sistance path — the resis tor labeled R47 in Fig. 52.
The f/22 lens move s the brus h to the thi rd resistance path; here, the S12 brush connects pin 9 of IC2 d irectly to positive battery, Fig. 52. Wit h the f/32 lens, the brush moves off the resistors to an open portion of the board.
Notice in Fig. 52 that the part of the mod e selector labeled S8 connects the minimum-aperture sw itch S12 to pin 9 at the S se ttin g. Then , with the release but ton partially depressed, you should
Figure 54
measure a voltage at pin 9 — a voltage which corresponds to the position of S12.
This volt age — the M D co mmon vo lt age — causes IC2 to indicate the proper dia phragm opening for the light condi tions. But, if you fail to set the smallest aperture, IC2 only lights t he overexpo sure or underexposure LED in the S mode.
W hat if the IC fails to receive the MD com mon vo ltage signal? You'll then find that the LED readout won't display the diaphragm setting at the S mode. Although you can't reach pin 9 of IC2, you can check the MD common volta ge at the top of the camera; just measure the voltage to the conne ction f rom the minimum-aperture
resistor shown in Fig. 54.
Set the mod e selector to the S posi
tion, Fig. 55. Then p artially depress the
release butt on and measure the MD com mon voltage. Without a lens, you should measure around 1.4V. Minolta specifies Figure 55
MO COMMON VOL TAGE
FLEX STRIP
the volt age range o f 1.1 to 2.2V without a lens.
With the MD f/16 lens set to the minimum aper ture, you should measure 200 to 300 millivolts. The f/22 lens should give you a reading of 2.9 to 3V. And the f/32 lens should provide the MD common voltage of 2.1 to 2.3V.
But, if you measure 0V, you know
there's a probl em with the minimum-
aperture resistor or with the mode selec
tor S8. First check the contact at th e right- ha nd side of the mode selector brush, Fig. 55. Notice that Fig. 55 shows the la ter model o f the camera. Here, Minolta added the bridge over the mode selector to maintain better brush contact.
If cleaning the mode selector doesn't solve the prob lem, susp ect th e mi nimum- aperture resistor. Al so, i t's possible that you have a break in the strip of flex cir cuit, Fig. 54. The flex- circuit str ip con
nects the minimum- aperture and dia phrag m resistors to the main circuit board. In that case, you 'll have to replace the compl ete resistor board, Fig. 53; we'll desc ribe the procedu re in a moment.
Poor contact in the diaphragm resistor also causes the overexposure LED to re main on. You can use another voltage check to test the diaphragm resistor after removing the top cover. Measure the volt age be tween ground and the AV contact.
Fig. 54; you should measure around 2.9V
with th e release button partially depressed.
Now rot ate the diaphragm-m etering ring against its spring tension as you mo nitor the voltage. You should see the voltage smoothly decrease to around 2.8V.
Figure 57
S PRING FOR DIA PHR AG M-M E TER ING RING
Figure 58
REPL ACING THE M INIMU M-
APER TURE RESISTOR
To clean and refo rm the bru shes of the minimum-aperture and diap hragm re sistors, you' ll probably have to remove the le ns-mountin g ring. You 'll also have to remo ve the lens-mounting ring to replace the resisto r board. Notice the position of the lens-m ounting ring in Fig. 56; the corner indicated in Fig. 56 must go to ward the bottom of the cam era.
Now remove the lens-mount ing ring by taking ou t its fou r screw s. Then lift out the bay onet sprin g, Fig. 57. Also d isc on nect the s pring from the dia phragm - metering ring, Fig. 58. When you lift out the diaphrag m-me tering ring, the spring should stay conn ected to the spring clip,
Fig. 59.
The long resis tance path you can now see, Fig. 59, is the dia phragm resistor; the brush remain s with the d iaphragm-
metering ring. To remove the bru sh assembly for the minimum-apert ure resis to r, disconn ect its spring and remove the
two shoulder sc rews. Fig. 59.
That's as far as you' ll have to go in disassembly to clean the bru shes and the resistor board. How ever, replacing the resistor board requires a little m ore work. First unsolder the seven connections join ing the resistor- board f lex strip to th e main flex cir cu it. Fig. 54. A new resistor board comes with th e strip of fle x circu it.·
Now remove the two screws, Fig. 59, and lift out the resistor board . Notice th at you can s hift the po sition of the resistor board before tightening the screws. The shifting adju stme nt allows you to precise ly a lign the minimum-aperture resistance paths, Fig. 59, with the brush.
When yo u inst all the new resistor board, be very careful to avoid over-
tightening the screw with the washer,
Fig. 59. Ove rtighte nin g the s crew can break the connectors within the fle x- ci rcuit strip. You'll th en have the same
problem — no MD common voltage.
Then, after you reassem ble the
dia phrag m-metering ring and the lens-
mounting ring, adjust the posit ion of the
resistor board . With no lens, the brush
should center on the first resistance path. Fig. 59. You might also check t he adjust ment with the f/16 MD lens installed. At the f/16 setti ng, the brush should center on the second resistance path.
CHE CKING SWITCH S7
As mentioned earlier, the LED display turns off when you release the shutter. When M1 repels its armature, switch S7 opens. Fig. 52. Opening S7 disconnects IC2 from ground. So, if S7 fails to make good contact, none of the LEDs will turn on.
W ith the front-plate/m irror-cage assembly rem oved, you have a good vie w of S7, Fig. 60. Fig. 60 shows the mirror cage in the charged position. The M1 ar mature now sits in co ntact with the core of the combin ation magnet. Notice that the pin on the armature comes aga inst the blade of S7. The S7 blade then con nects to ground through the armature.
S7 remains connect ed to ground until the M1 armature moves away from the core. In Fig. 61, we're holdin g open the shutter on bulb. Also , we'v e pushed the
M1 armature away from the core . As you can see, th e pin on the armatur e has moved away fro m the S7 blade.
A fter the exposure, the cam ridge on the mirror-tensioning lever, Fig. 62, once again drives the M1 armature against the core of the combination magnet. Cocking the mirror cage for the next exposure moves the cam ridge away from the M1 armature . Fig. 60. But, because of the
permane nt magnet in the core of M1, the
armature remains in place.
You ma y have to remove the front- plate/mirror-cage assembly to repair S7. Howev er, you can check S7 by just removing the bottom plate. The white
wire connected to the S7 blade, Fig. 62, goes to the lower cir cuit board.
Suppose, then, that none of the LEDs will turn on. Tr y checking the co ntinuity betwe en t he white w ire an d gr ound. You should measure direct con tinuity until you
release the s hutter on an electronica lly co ntrolled speed. If you don't measure
direct continuity, S7 isn't making good
contact with the M1 armature.
Figure 59
RE S I S T O R - B O A R D SC R E W S
Figure 60 Mirror charged
WH IT E
DI A P H R A G M - CO N T R O L
Figure 61
RA T C H E T G E A R
Figure 62 Mirror released
DIAPHRAGM-CON TROL CIRC UIT
In the S m ode, IC2 tells you w hat diaphragm op enin g you should get. But IC1 provides the actual calculation and control . Fig. 63. Th e comparator inside IC1 co mpares t he shutter- speed informa tion with the light-leve l and film -speed in fo rmatio n to make its decision — the dec ision wh en to turn on T13, Fig. 63.
Rem ember that S7 remains closed unti l the M1 arma ture move s away from the core. With S7 closed, the base of T13 connects to ground through R64. Howev er, when S7 opens, the base o f
T13 sees a positive voltage. The volta ge
applied to the base of T13 is the sum of
the voltage d rops across each of the
diodes shown next to S7 in Fig. 63 —
around 1.2V. In the camera, you can see the two diodes next to H-IC, Fig. 48.
T13 now has the positiv e voltage it
needs at its base. However, the transistor
still can't conduct. Th at's because the
voltage at pin 9 of IC1 — the ou tput of the comparator — remains high. In effect,
opening S7 just prepares T13 to t urn on. T13 then rem ains at the ready, waiting
on ly for the voltage at its emitter to
switch low.
The comparator inside IC1, Fig. 63, contr ols the emitter voltage of T13. At pin 11, the comparator sees the sh utter-
speed inf ormation from RTV. T he com
par ato r sees the film-sp eed an d bright ness informati on at pin 8. As long as th e
voltage at pin 11 remains less positive than the voltage at pin 8, the ou tput of
the comparator stays h igh.
However, as the diaphragm stops down, the voltage a t pin 8 decreases. Why? Because the SPC sees less light. When the voltage at pin 8 reaches the voltage at pin 11, the compara tor switches states — its output g oes low. The voltage at pin 9 of IC 1, Fig. 63, then switches to OV.
S witchi ng t he e mitter of T13 to OV pro
vides the transistor w ith a forward bias of
1.2V; remember, T13 already has the 1.2V signal at its base. T13 no w turns on, sending base current through T5. When T5 turns on, C5 discharges throu gh the coil of M2 to arrest t he diaphragm closur e.
The shutter -speed setting, as you've seen, just chang es the voltage input a t one lead of the comparator. So, to check the shutter-speed resistor RTV, you can measure the pin 11 voltage in the S mode. You sh ould see the voltage go more pos itive as you set faster shutter speeds. Since the voltage goes more positive, the diaphr agm do esn't have to stop do wn as far in bringing the pin 8 voltage to the pin
11 voltage.
At the X, B, an d 0 settings, t he shutter- speed brush moves to the gro und land
sh ow n just be low the RTV resistor in Fig.
63. Pin 11 of IC1 n ow connect s to ground. As a re sult, the voltage at pin 8 never reaches the voltage at pin 11. And the diap hragm-clos ing lever a lways has its full movement.
Y ou'l l notice that the diaph ragm- closing system works i ndependently of the r eadout. In the first part of th is article, we men tioned that the M C lens w on't give you the proper indication in the LED display; i t lacks the tab which couples to the minimum-aperture resistor. However, you can still use the MC lenses with the camera. Although you won't get the diaphragm read out, the lens nonetheless sto ps down t o the prop er aperture in the S mode. T he diaphragm-cont rol magnet still arrests the diaphragm closure.
W ith the front-plate/m irr o r-cage assembly removed, you can see the diaphragm-control ma gn et, Fig. 62. Locate the ratchet gear in Fig. 62. Whe n C5 discharges through the coil of M2, the armatu re moves int o engagement wit h the ratchet gear. Stoppin g the rotation of the ratchet gea r also stops the mo vement of the diaphragm-closing lever.
In the A a nd M modes, the diaph ragm- closing lever mus t again have its full movement. The diaphragm th en closes to whatever f/ stop you'v e selected. When
you select either A or M, switch S11 (part of the mode s witch ) connects pi n 11 of IC1 to ground through the trigger switch S4. Cons equently, the pin 8 voltage never reaches the pin 11 voltage.
OPERATION IN THE A MODE
In the A mo de, the shutter- speed resi stor RTV has nothing to say about the operation. Switch S9, Fig. 63 (another con tact on th e mode switch) disc onnects
the shutte r-speed resistor from the cir
cuit. Then, regardless of your shutter-
speed setting — 1 second through 1/1000 second — you get an automatically con trolle d shutt er speed.
The charge across the memory ca
pacitor C2 now controls the exposure
time. Fig. 64 shows the circuit inside IC1 that c harges the memor y cap acitor an d
contro ls t he current to the timing ca pacitor C3. As long as the m emory switch S6 remains closed, the charge acros s the memory capacitor can con tinue changing.
W he n the diaphragm reaches the pro per aperture size, the memor y sw itc h opens. No w the mirror starts to rise. Even though the SPC can no longer see the light com ing through the lens, the circuit has a mem orized referen ce voltage — the voltage stored in the mem ory capa citor.
Notice in Fig. 64 that the memory- ca pacitor voltag e pro vides the base bias for transistor #1 inside IC1. The transistor bias determ ines how fast the t iming ca pacitor C3 can charge. However, the timing capacitor can't start charging until the trigger switch S4 opens. As lo ng as
S4 remains closed, it keeps t he C3 com par ato r switc hed low. In turn, t he com parator keeps transisto r #2 turned off.
The n, as the opening blade starts to
move, it ope ns the tr igger s witch. The C3 comparator now switches high and t urns on transistor #2, Fig. 64. As a resul t, cur rent fl ows from ground, through tran
tromagn et M3, Fig. 64. Right now, the output of the M3 comparator remains at OV. The electromagne t then has a 3V dif ference in potential. Since current flows through the coil, the M3 electromagnet holds the clos ing blade to keep the shut ter open.
Then, when the timing capacitor reaches a high e nough voltage, it triggers the M3 comparat or. As a re sult, the com parator switches states — its o utput goes to 3V. Now there's no difference in potential across the electromagnet. So the electromagn et releases it s armature and frees the closing blade.
sistor #2, and through tra nsistor #1 to
charge the t imin g capac itor C3.
The higher the memorize d reference vol tage, the f aster the ti ming capacitor wi ll c harge. A high er reference voltage pro vides a larger base drive to transist or #1, Fig. 64. Transistor #1 t hen cond ucts more current.
Du ring the C3 charging cycle, current
flows through the clos ing-blade elec
FRONT OF CAM E R A
3 V |
0.45 —0.8 V ( ] 0.5 —0.7V
0.2V [ ~ | 1.33—1.36V
0.7V f
ον Γ 1
1.0 6-1.25V f
(0 .16 -0.1/V LOWER
THAN PIM If)
0V UNTIL RELEASE
0.5 —0.7V t (MORE POSITIVE 1 .0 - 1 .1V (A. M MODES) AS C2 VOLTAGE INC REASE S)
1.13V I
1 20
2 19 3 18
4 17
5 16
6 15
7 14
8 13
9 12
10 11
OPERATION IN TH E M MODE
In the M mode, the shutter speed still dep ends on the charge across the memory capa cito r. However, the shutter- speed setting (the res istance of RTV) determines the memo ry-capacito r vo lt age. At M, swit ch S9 moves from the
"AS" position to the "M " position. Fig. 63.
1.1 —1.36V (M MODE)
1.1 —1.4V (A. S MODES)
] 1.1 — 1.2V
I ov
.] 1.9 — 2.4V
J OV l 2.8—2.95V
kXPOSU RE)
J 1.1 — 1.36V (S M OD FI
--
Figure 65 Voltages with S5 dosed, shutter cocked
Figure 66
Swi tch S9 now connects RTV to pin 20 of IC1, Fig. 63. As you set faster shutter speeds, the voltage at pin 20 goes more
positive. T he voltag e at pin 19 also goes more positive at the faster speed s ettin gs.
As the vo ltage at pin 19 goes m ore positiv e, the volta ge acro ss the memory capacitor increases. T he rema ining opera tion mat ches t hat we described for automati c oper ation. In creasing the vol tage acros s the mem ory capacitor pro vides a lar ger base dri ve for transistor #1, Fig. 64. The tim ing capacitor then charges more quickly.
You can then check the shutter-speed resistor RTV b y measuring the voltage to pin 20 of IC1 in the M mode. Again, the voltage should go more positive as you set faste r shutter speeds. At the X, B, and 0 settings, though, you should measure OV at pin 20.
What if you measure OV at the othe r settings? The re's evidently an open in the shutter-spee d resi stors. Most likely, you'll simpl y find p oor contact between the bru sh at th e bo ttom of the speed sele ctor,
Fig. 55, and the RTV resistance band.
You can then remov e the speed selector
(a procedure we'll later des cribe) to im prove the brush c on tact and clean the
surfaces of RTV.
Here's a nothe r possiblity — the shutter works fine through out part of the speed range ye t hangs ope n dur ing the rest of the speed range. For example, you may
find that the shutt er work s properly a t the
speeds of 1 second through 1/60 sec ond.
But it hangs open at the speeds of 1/125
second through 1/10 00 second.
The problem cou ld in dicate a break in
the RTV resistance band. But you may
fin d that the RTV resistor board has sim ply shifted out of position. As a result, the speed -selector bru sh rides off t he resistance band. Try s hifting the position of the RTV resistor board after loose ning its three screws, Fig. 55.
PIN VOLTAGES, IC1
Once yo u 're familiar with the schem atic, you can perfo rm much of the troubleshooting at the pins of IC1, Fig.
65. Fig. 65 shows the pin voltages for IC1 with the metering switch S5 clos ed.
Normally, the voltage at pin 1, will be a li t
tle less than 3V; it 's the battery voltage
min us the drop across T1, Fig. 63.
Earlier, we indi cated th at you can
che ck the RTV resistor at pin 20, Fig. 65.
In the M mode, the voltage sh ould go from a rou nd 1.1V at the 1-second setting to around 1.36V at the 1/100 0-se cond setting. Y ou should measure 0V at the 0, X, and B settings. If you measure 0V at any of the other sett ings, sus pect poor contact in the sh utter-speed resistor.
Pin 19, Fig. 65, provide s the ch arging
voltage for the memory cap acitor. The
voltage a t pin 19 should go m ore p ositive
as you set fast er shutter speeds on manual or as you increase the light level on automatic. The same voltage appears at pin 10. Pin 10 couples the memorized reference voltage from the memory ca pacitor to the current-control circuit that charges the tim ing capacitor.
At p in 9, yo u should see a OV signal un til you release the shutter. The volta ge the n swings positive to negative (OV) to turn on T13.
You can check switching actions at the other pins. For example, pin 12 connects to the tri gger switch. With the shutter cocked, you sh ould measure OV at pin 12; the closed trigger switch then connects pin 12 to groun d. However, yo u should
measure around 1,3V d uring the exposure wh en the trigger switch opens. What if you don't? If the vo ltage stays at OV, sus pect a problem with the t rigger
switch.
Another swit ch — S11 of the mode switch — connects to pin 11. If the shut ter delivers on ly the mechanical exposure in all modes, you mi gh t check the pin 11 voltage. You should see the v oltage change as y ou move the mode switch from the S position to the A po sition. If
not , suspect poor contact in S11.
As another example, S9 of the m ode switch con nects to pin 20. Here, you sho uld see a volta ge chan ge as you go from th e M mode to the A mode. Poor
contact in S9 could cause the shu tte r t o hang open in all m odes. Fig. 66 points ou t the mo de-switch pa ths that corr espo nd to S8, S9, S11, and S13.
MODIFICA TION TO THE
TIMING CI RCUIT
You may recall the symptom of a shorted memory cap acitor C2 — the shut ter hangs ope n on all modes. With no voltage across the memory capacit or,
trans istor #1, Fig. 64, has no base drive. Consequently, it can't charge the timi ng capac itor. The same symptom may result from p oor contact in the memory sw itch.
Simila rly, under very low light cond i tions, there's a low volta ge across the memory capacitor. If you operate the camera at one of the automatic setting s in complete darkness, the shutter hangs open until the batteries die. You can, of course, remove the batteries to close the sh utter. But Minolta discovere d that ow ner s were going through b atteries by let ting their s hutters hang open.
At the current p rice of silver-o xide bat teries, Mino lta felt the prob lem deserved a modification — a modification that allows the timing capacitor C3 to event
ually charge . Minolta suggests adding a large-v alue resistor — 50 megohms — be tween pin 14 of IC1 (gro und) and the negative lead of C3, Fig. 55.
The large resistor has no effect on the normal operation. However, it allows the timin g capa citor to eventually ch arge and close the shutte r. You may have some trouble locating a 50M resistor that's small enough in size. Fort unately, Minolta does su pply the resistor through their
parts dep artm ent; i t's p art number
9431-1078-31.
REPAIRING AND ADJUSTING
THE COM BINAT ION MA GNETS
We've alread y d escribed the troubl e shooting steps to detect an open coil in
either M1 or M2, Fig. 63. Remember, an open M1 coil prev ents the mirror fro m releasing. If M2 has an open coil, the
diaphr agm always stops down fully in the
S m ode.
Howev er, you may also encounter mechanic al problems w ith the combina tio n magnets. Dirt causes one such prob lem. For example, dirt between the M1 ar ma ture and the magnet core preve nts the magn etic attraction. As a result, the mir
ror releases as soon as you comple te th e co cking s troke.
Dirt can cau se a sim ilar problem with the M2 magn et. If M2 fails to hold its ar mature, the d iaphragm ca n't s top down. The armature arrest s the ratchet gear as soo n as the diaphr agm star ts to close.
M inolta has improved both the M1 magnet and the M 2 magnet to m inimize the dirt prob lem. In the newer designs, the armature moves a rod within a hole. The hole serves to seal both the armature and the core from dirt.
Incorrect adjustments cause similar
problems. But y ou normally don't have to
ad jus t t he magnets — not unless you've
replaced either M1 or M2. If you replace a ma gnet, you'll have to adjust its po sition.
Check the adjustment on M1 with the
mirror cage in the charged posi tion, Fig.
67. The end of the M1 armature should
now overlap the top of the charge cam, Fig. 67, by 0.1 to 0.15 mm. Also, there
should be a space gap of 0.3 to 0.8mm
bet ween the M1 armature and the mirror- release lever, Fig. 67.
To adjust M1, just loosen its two screws, Fig. 67. Then shift the posit ion of the ma gnet. Also check to make sure that the armature comes aga inst the magnet core, Fig. 67. If the M1 armature fa ils to engage the core — yet the M1 ad justment appears to be correct — you can reform the section of the armature tha t carries the keeper, Fig. 67.
The dia phragm-control m agnet M 2 has a similar sliding adjust ment. Set the speed selector to bulb. Then coc k and
release the mirror cage; hold down the release slide to keep the mirror in the raised posit ion.
Now push the M2 armature away from
the core , Fig. 68. Check the space gap bet ween the core and keeper at the end of the armature; the spac e gap should be
bet ween 0.4 and 0.6mm. To adjust the space gap , loosen the two screws and shift the positio n of M2.
Figure 67
Figure 68
EXPOSURE AND READOUT
ADJUSTMENTS
For many of th e repairs in the XD-11, you won't have to disassemble the camera any further than we've described. The modular c onstructi on then makes the camera fast to service. Let's say you've
replaced the front-plat e/mir ror-cage assembly. You're then ready to make the adjustments.
Remember th at you should avoid dis
tur bing the two variable resistors for the
LED rea dout — Rx5 and Rx6, Fig. 48. Set ting up the other adju stments should brin g
in the accurac y of the LED display. But, if
the LED rea dout remains off by more than
1 EV, you can pull out the front-plat e/-
mirror-cage assemb ly f ar enough to reach
the variable resistors. It's also possible —
though not recommended — to reach the
adjustments thr ough the cuto ut on the
side of the lens mount . Using a cu rved tool
to turn the "blind” variable resistors could
do more harm than good.
Start by checking the MD common volt
age, Fig. 54. We described the test during troubleshooting. As you'll recall, you should measure fro m 1.1 to 2.2V wit hout a lens installed. T here's no adjustme nt on the MD common voltage other than shift ing th e minimum- apertur e resi stor. However, if you aren't getting the M D comm on voltage, yo u won't be able to ad
just the LED readout in the S mode.
CALIBRATING THE MANUAL SHUT TER SPEEDS
The two variable resist ors at the front of the fle x ci rcuit. Fig. 69, provide your ad jus tments for the manual speeds. Rx7 adjusts the constan t-c urrent source. With the pro per amount of curren t to the tim ing circuit, the shutter speeds should be linear.
Set the mode swi tch to M. Then con nect a digita l voltmeter between Rx7 and fixed resistor R56 as shown in Fig. 69. Depress the release button part way t o measure the voltage.
You should get a read ing of 180mv
(0.180V) ±2mv. If no t, make the a djust ment usin g Rx7. Turning th e wip er of Rx7 in a clockwise dire ction causes the voltage to increase.
Now use vari able resistor Rx3, Fig. 69, to adjust the m anual 1/30-sec ond shutt er speed. Mino lta recommen ds s etting the exposur e t ime to 31.2ms. The othe r
manually calibrated shutter speeds should then time prope rly.
But you'll sometimes find that the
fastest speed — 1/1000 secon d — re mains too slow. In that case, che ck first the blade-tr avel times. The blades should cross a 20mm distan ce in 6ms. If not, you'll have to remove th e shutter and ad
just the blade tensions.
There's one more adjustme nt t hat af
fects 1/1000 second — the eccentric for the shut ter's trigger switch . Changing the moment a t wh ich the trigg er switch opens has a signific ant effect on 1/1000 second. But the adjustment has very little effect on the ot her shutter speeds.
It’s possible — albe it delicate — to ad
just the trig ger swi tch without removing the shutte r. You can reach the eccentric
through the cle arance cutout shown in Fig. 70, However, you're again faced with
a "blind" adjustment.
Later, after we remove the shutter,
w e'll go through another technique you
can use to adjust the tr igger switch — one that involves adjusting the eccentric for 1/1000 second befor e replacing the shut ter. Still, you won't want to remove the shutter for ev ery XD-11 repair. You may then have to use the clearance cutout, Fig. 70, to adjust 1/1000 second.
Figure 69
Figure 70
ADJ USTING THE ASA INCLINAT ION
Variable resistor Rx1, Fig. 71, sets the ASA inclin ation — the actual signal cha nge for a change in the film-speed set tin g. Properly adjusting the ASA inclina tion should elimin ate the need to disturb
Figure 7 1
the variable resistors on the side of the mi rror cage.
To c heck the AS A inclination , measure the voltage between the lead of Rx1 and the fl ex-c ircuit land tha t has the gray SV
wire, Fig. 71. You should measure 144mv
±2mv. Adjust the v oltage by turning the wi pe r of Rx1 — clockwise to decrease th e voltage, counterclockwise to increase the volt age.
AUTO EXPOS URE ADJU STM ENT
Adjus t Rx2, Fig. 71, to correct the auto exposure in the A mode. Minolta recom mends test ing th e automatic s hutter
speeds at f /5.6, ASA 100. Check the ex
posu re at EV 15, EV 11, and EV 9. Be sure
to shield the top of the camera fr om am
bie nt li gh t, especially at t he EV 9 light level.
LED in the display centers within its hole in th e viewfinder mask.
You're then ready to verify the ac curacy of the r eadout. First c heck the ac curacy in th e A mode, ASA 100, and EV
11. At f/2.8, the "250" LED should turn on. At f/ 8 , the "30" LED should t urn on.
And at f/16, the "8 " LED should turn on.
Next check the accuracy in the S mode
at f/16, EV 11. At 1/15 second, the f/11 LED should tu rn on. The f/ 5.6 LED should turn on at 1/6 0 s econd. At 1/500 second, the f/2 LED should turn on.
If the LED readout is not wi thin 1 EV, recheck your previous adjustments. Use variable resisto rs Rx5 and Rx6, Fig. 48, only as a last resort. If n ecessary, you can then us e Rx5 to adju st the readout in the S mod e. Use Rx6 to adjust the readout in the A mode.
CHECKING THE AUTO DIAPH RAGM OPENINGS
There's no adj ustment for the auto
diaphra gm openings. However, you should still check the ac curacy. Checking the auto diaphragm openings a t t he S
mod e verifies p roper operation as we ll as the acc ura cy of the previous adjustments.
Se t the mod e selecto r to S. Then check
the diaphra gm opening at ASA 100 and
EV 11. Remember, the diaphragm-setting ring must be at the smallest ap ertu re set tin g. The following chart shows the ac tual aperture and the exposure time you should be ge tting at different shutter- speed settin gs:
ADJUSTING THE UNDERRANGE
LED INDICATION
The final "normal" adjust me nt sets th e turn-on point of the underr ange LED. But the adjustment takes some time — you
have to compare two voltage me asure
ments. First, set the mode switch to S, the sh utt er speed t o 1/250 second, and the diaphragm to f/16.
With the film-speed dial set to ASA
100, expose the lens to a light level of EV
9. Now me asure the voltage between the common S11 path, Fig. 66, and ground.
Record yo ur voltage reading.
Next, without changing anything, mea
SHUTTER SETTING DIAPH RAGM OPENING EXPOSURE TIME
1/1 25 second f/4 3.91 - 15.6ms 1/60 secon d f/5.6 7.81 - 31.3ms 1/3 0 s econd f/8 15.6 - 62 .5ms 1/1 5 s econd f/11 31.3-125 ms
If you're using an instrument that measures EV error, the exposure should be
withi n ±0.8V at each shutter-speed setti ng. An out-of- tolerance reading normally
indicates an error in the previous adjustmen ts.
CHECKING THE LED REA DOUT
Now check th e accurac y of the LED readout. Check firs t to make sure that the LEDs l ight properly all along the scale. I f
the LEDs at either end of the scale don't show up — or if the LEDs don't appear unif or mly bright or cente red thro ughout the display — you m ay have to shi ft the ci rcuit boa rd at the side of the mi rror cage, Fig. 48.
The LED display mounts to the circ uit board at the other side of the flex circ uit, Fig. 48. After loo sening the two ground screws, you ca n s hift the p osit on of the circuit board to align the LEDs with the mirror-cage prisms. Make sure tha t each
sure the voltage b etween pin 8 of IC1 and ground. You can measure the pin 8 voltage at th e gray-wire land pointed out in Fig. 71. Compare this voltage reading with your measurem ent at the S11 land.
Finally, turn the film-speed dial until the voltage at the gray-wire land is 12 to 13mv lower than the voltag e at S11. For exam ple, suppose that you measured 1.313V in the first step. You must then set the voltage at the gray-wire land to 1.3
-1.1301V. Move t he f ilm-speed brush along the resistance band unt il you get
the proper voltage at the gray-wire con
nec tion.
N ow look th rough t he finder — the
undere xposure LED should just begin lighting. Adjust Rx4, Fig. 71, so that the underexpos ure LED just starts to glow
when the f/1.4 LED turn s on.
CHECKING THE DEDICATED- FLASH OPERATI ON
Before closng up the camera, you should check t o make sure the circuit will program the f lash speed and indicati on with a dedicated flash. The AX signa l pin, Fig. 71, receives the signal from the fla sh un it. With the flash unit fully ch arged, the signal at pin 1 of H-IC, Fig. 63, turns on tra nsistor T10.
Turning on T10 conne cts pin 11 of IC1 to ground. Consequently, the diaphr agm always closes to whate ver f/ stop you'v e selected. Also, transistor T9 turns on, connecting on e lead of the electr omagnet to groun d. The shutter then stays open for a length of t ime determined b y the flash uni t. As soon as the flash unit turns off T9, the shutt er closes.
So, if you a pply a p osit ive signal to the AX signal pin, you should be able to hold open the shutter. The positive volt age keeps tran sistor T9 turned on. Since turn ing on T9 conne cts one lead of M 3 to ground, current continues t o flow through the electr omagnet.
Also, the positive signal should tur n on the overrange LED. In Fig. 63, you can trac e the s ignal fr om pin 1 of H-IC to IC2. The s ignal at pin 5 of IC2 turns on the over range LED.
Conn ect a DC power supply b etween ground (ne gative) and the AX signal pin. Set t he mode switch to M, and set th e speed selector to 1/1000 second. Before turning on the power supply, check the
LED indication by depressing the release button; you should get the available-lig ht indicatio n.
Now set th e powe r su pply to 1.3V. W he n you push the release bu tton p art wa y, t he overrange LED should turn on. Next se t the power s upply t o 1.6V and release th e shutter. The shu tte r s hould stay open until you turn off the power sup ply.
minolta 3CD11
CLEANING THE BLADES OF THE SEIKO SHUTTER
Several ca meras now use th e Seiko
mo dular foca l-plane shutters. Not all camera manufacturers, however, provide individual replacement parts. Many will only sup ply the shut ter as a complete
mod ule.
Bu t, thank s to Minolta, you have a
choice — you can either replace th e
modu le as a unit or you can repa ir th e shutter. Mino lta does suppl y t he parts in dividually, and most of the XD-11 sh utt er
parts wil l interchange with those used in
ot he r Seiko shutters.
Three screws hold the shutter module
to the mirror cage — t w o a t the top of the
Figure 72
blade as sembly, Fig. 72, a nd one at the front of the front p late (under the leatherette near the self-timer lever). You don't have to remove the eyepiece blind to reach t he shutter-retaining s crews as
we did in Fig. 72; just push the eyepiece
blind to its raised position.
Howev er, th e most common shutt er repair in the XD-11 doe sn't require sep arating the shutter from the mirror cage. For most of the shut ter repairs, you need only clean the blad es. Oil causes the blades to stick together .
Sticking blades often c hop off pa rt of the picture. You can spot the pr oblem b y watching the blades f rom the back of the aperture as you release the shutter. If
SHUTTER-MOUNTING SCREWS
REAR COVER PLAT E
there's oil on the blades , you'll n ote the sluggis h movement. In o ther cases, yo u may find th at the shutter occasionally
jams — the closing blade d oesn't quite
complete its release movement. T hen, by pushing down the cl osing blade from the back, you may be able to get the shutte r to operat e for several cycles before jam ming again. Again the problem re sults from oil on the blades.
Seiko later modified the blade s to minimize the sticking problem. The new- style blades have dimples which prevent pe rfectly flat blade-to-blade contac t.
To clean the blades, first remove the four sc rews whic h hold the rear cover plate, Fig. 72. As you lift off the rear cover plate, watch fo r loose pa rts. The closing-blade set has six loose sections; the opening-blade set has four loose sec tions. You'll also find loose spacers and washers.
Earlier shutters have loose washers over the pivot posts, Fig. 73. S ome ver sions don't have the wa shers; rather, they have loose collars over the rear- cover support posts. Lift out the loose washers or c ollars. Then remove the six indiv idual section s of the closing-blade set. It helps to keep the bla de se ction s in their prop er sequence for reassembly referenc e. Fig.
74.
Next lift out the ape rture mask, Fig. 75, and the four individual sections of the opening- blade set, Fig. 76. In some ver sions o f the shutter, you'll find another pair of washers over the pivot posts. Fig. 77.
Also n ote the loose shims and the loose rubberlike dam pers, Fig. 77. The damp ers serve to c ushion the opening blade. Some versions of the shutter have a wh ite
Figure 73
WASHERS
Figure 75
Figure 74 Closing-blade set (Part #2005-0712-01)
Figure 77
Figure 76 Opening-blade set (Part #2005-0713-01)
UPPER ARM
ARM
CLOSING- BLADE
Figure 78
damper, similar in appearance to the
op ening-bla de damp ers, which fits int o a
slot to the right of the blades. Fig. 77.
On reassembly, first seat the shims and the da mpers as shown in Fig. 77. Ne xt place the wash ers over the pivot posts.
The multip le-sectio ned blade of the opening-blade set, Fig. 76, may be the on ly "tricky" blade to replace. Fir st posi tion the two blade arms as shown in Fig.
78. Notic e that the brass b ushing on the upper a rm fi ts over the small pin, and the hole fits over the post on the opening- blade driving lever (the lever that actual ly drives the blade set up and down). To posit ion the lower arm, fit its hole ov er the pivo t post, Fig. 78.
Now swing the large s ecti on of the
blade into place. Sea t the slo t in the large
section over the post on the openin g-
blade driving lever. Fig. 79. As you replace each of the re maining sections, fit the blad e slot over the opening-blad e drivin g lever and fit th e blade hole over the pivot post. Once a ssemble d, the opening-bla de set s hould cover the focal-
plane aperture.
Ne xt replace the aperture mask and the six in dividual sect ions o f the closin g-blade set. The slot in each blade fits over the post on the closing -bla de driving lever, Fig. 79. The hole in each blade fit s over the pivo t post.
In the closing-blade set, the multiple- sectioned blade goes last. Fit t he brass bushing over the small pin, and seat the
hole in the same arm over the post on the closing-bl ade driving lever. Fit the hole in the other arm over th e pivot post. Fig. 73
REMOVING THE SHUTTER
To remove the shutter, take out the three shutter- retaining screws. Then lift the shutter far enough fr om the mirr or
Figure 79 First section of opening blade in position
Figure 80
cage to reach the wires which co nn ect t o the shutter-terminal board.
Notice t hat the w ires pass behind a clamp at the side of the focusing-screen mount, Fig. 80. Bend t he clamp to free the w ires. Then unsolder the four wires from the shutter-terminal board — red and br own to the electromagnet, gra y to the X-sync contact, and the black to the trigger swi tch, Fig. 81.
Wi th the sh utter remo ved, you have a better v iew of the trigger-switch eccen tric, Fig. 82. The eccentric, acce ssible th ro ugh a cu tout in the front plate, pro vides yo ur 1/1000-second ad justment.
However, you may prefer to set the trigger-sw itch ad justment before you replace the shutter.
Why? That way, you 're sure the s hu tte r
is right before you start adjust ing the
shutter speeds. Also , some of the
cameras which use the S eiko shutters don't provide clearance cu touts over the trigger-switch eccentric. As a result, you
can't reach the trigger-switch eccentr ic
with the camera assembled.
Adjusting the trigger-switch eccentric wit h t he shutter removed requires a special test ci rcuit. With the test circuit connecte d to the shutt er's electromagnet and t rig ge r switch, the shutter should deliver 1/1000 se cond . The test circuit simply simulates the camera's ti ming cir cuit at the 1/1000-second setting.
So, with the test cir cuit connected, you can ad just th e trigger-switch eccentric f or an a ccurate 1/100 0 second. The test box shown in Fig. 83 has a tw o-position switch to allo w the selection of a second shut ter speed. A slower shutter-speed ca pa bility can be handy as an oper ational check . Remember, with no cur rent
Figure 81 Shutter-terminal board Figure 83
through the electromagne t, the Seiko delivers a mechanical speed th at's very close to 1/1000 second. Co nsequently, you may find that you’re trying to adjust th e trigger swit ch when you're really getting the mecha nical speed. By fi rst checking the opera tio n at a slower speed, you can at least be certain that you’ve properly conn ected the test circuit.
For the XD 11 alone, the test circu it may not be worth the
trouble. Howeve r, you can use the test circuit for any of the
TRIGGER-
ELECTROMAGNET WIRES
SW ITCH CONN ECTIO N I
LECTROMAGNET
mod ular, electr onic foca l-pl ane shutters. And, since some cameras don' t provide a clearance cutout over the ecce ntric, you may find that the test circuit comes in handy. A little later, we'll desc ribe a couple of differ ent ways you can build the test circuit.
MEC HANICAL O PERATIO N OF TH E SEIKO SHUTTER
Advance th e shutter-cocking lever. Fig. 82, t o cock the shutter. Notice that the opening-blad e set, Fig. 84, doesn't move during the cocking cycle — it's already at the top o f the aperture . But the closing-bl ade set, visible from the back of the shutter, moves up during the cocking cycle.
To release the shutter, push do wn the release lever, Fig. 84. The o pening blade should then move down, un cov ering the aper ture. Howeve r, the closing blade shou ld remain latc hed to keep the shutter open.
To free the closi ng blade, pu sh the bulb lever out of engage
ment with the ar mat ure — from left to righ t in Fig. 84. The spring- loaded armature then moves awa y from the ele ctromagnet and
strikes the closing-bl ade latch. Whe n t he closing blade moves
down to end t he exposure , it strik es a latch hold ing the opening blade.
TRIGGER-SWITCH ECCEN TRIC
REL EASE-LEVER
SPRING
SH UTTER-COCKING LEVER
Figure 82
ARMA TUR E
CLOSING-
BLADE
RA T C H E T
Figure 84
Figure 85
Now a spring drives the opening blade to
the top of the aperture — back to th e
"rea dy" position. With the shutt er re leased, both blades cover the ape rture.
Since only one blade moves during the
cocking cycle, the Seiko has a smooth
wind stroke whic h adapts well f or use with a power win der. You can get a better idea of the operation if you try pulling
down the arm on the openin g-blade driv
ing lever. Fig. 84, with t he shutter in the
released position. Pulling down the arm should mov e the opening blade to the bottom of the aperture. When you let go of the arm, the return spring drives the openin g blade to the raised position.
Also try ope rating the shut ter while you' re holding the bulb lever fu lly clockwise. Fig. 85. You s hould then get
the fast mechanical speed — somewhere
bet ween 1/100 0 a nd 1/2000 s econd. Here, the bulb lever can't engage the
armature. And, sin ce there's no current th rough the electromagnet, the armature releases the closing blade immedi ately.
To set the 1/100-secon d mecha nical
speed, hold the bulb leve r in its center position, Fig. 85. The bulb lever still c an't engag e the armature. But anot her lever
— the mechanical-speed lat ch — holds the armature to provide the full-aperture speed.
The m echanical-sp eed latch sits just under the bulb lever, Fig. 86. When the opening blade crosses the aperture, it disengages the mechan ical-speed l atch. Now the armature frees the closing blade.
W he n t he bulb lever moves to the electronic-spe eds positi on — fully clockwise, Fig. 85 — it pulls the
mechanical-speed latch away from the
armatur e. Neither t he mecha nical-speed
latch nor the bulb lever then has any ef
fect on the operation.
REPLACING THE SHUTTER
In normal operation, the m echanic al- speed lever. Fig. 87, controls the bulb lever. A cam under the shutter-speed resistor pos itions the mechanical-sp eed
lever. Also note the tab on the release
slide in Fig. 87. The tab p ulls the bulb
lever ou t of engagement to en d the bulb
expos ure.
On reasse mbly, first cock the shutter.
Then position the wire s t hrough the wire clamp, Fig. 80, as you seat t he shutter on the mirror cage. Make sur e tha t the bulb
lever passes to the inside of the mec hanical-speed lever, Fig. 87, and that
the bulb- lever pin sits above the release- slide tab.
ADJ USTI NG THE BLADE- TRAVEL TIMES
Both blades should cross a 20mm
distance in 6ms . To increase the te nsions ,
rotate the blade ra tchets, Fig. 84, in a
Figure 86
Figure 87
clockwise direction. However, to let off tensions, y ou mu st disengage the pawls from the ratchets.
In most cases, you'll be adding tension
to speed up the blades. Rotating the
opening-blade ratchet o ne click-stop in a clockwise directio n increases the travel time by around 0.1m s. An increase of one click-stop o n the closing-blade ra tchet provides around a 0.2m s increase in the travel time.
It' s a little more di fficult to let off ten sion. Probably the easiest way is to simply disengage the appropriate spring pawl and allow the drive spring to completely unwin d (around 1/2 turn). Then build up the tension from scratch.
Checking th e travel times with the shut ter removed presents anot her prob lem — it's awk ward to hold t he probe behind the blades as you opera te the sh utter. However, as you'll see in a mo ment, you can visually set the ratchets very close to the prop er positions. You can then replace the shutter. Even with the shutter installed on the mi rror cage, you can reach the tension-setting rat chets, Fig. 87.
Temporarily seat the f ron t-plate/mirror- cage assembly in the body casting. Then, with the speed selector set at the 1/1000-second mechanical speed, measure the blade-travel times. Remembering the am ount of correction you need, pull the front-plate/mirror-box assembly and make the adjustments. Suppose, fo r example, that you measure an opening-blade travel time of 6.2ms. Y ou now know that you must add two clicks of tension to the opening-blade ratchet.
REPA IRS IN THE CONTROL
SECTION OF THE SEIKO
Oth er than cleaning the blades, there ar en't many common repairs in the Seiko shutters. If you're getting overexposures at h igh-l ight levels and fast man ual speeds, try cleaning the surfaces of the electromagnet core and armature, Fig.
82. Oil o n the interface causes stick ing. As a result, th e electro magnet can't release its armature quickly enough.
Also, you'll occasion ally find that for ce
has sheared off one of the pins in the
shut ter — either the pin on the shutter- cocking lever or the pin on the opening-
blade driving lever. If you can find the missing pin, you can restake it to the lever. Otherwise, you'll have to rep lace a
part .
Co mplete shutter disassembly does disturb some a dju stment points. For one, you must let off the blad e tensions. Also, you'll lose the initial tension on the timing cam. Fig. 86.
During the cocking cycle, the shutter- co cking lever rota tes the timing cam in a clockwise direction. A cam ridge on the timing cam then all ow s the trigger swi tch to close. Also, t he timing cam pushes th e armature against the electromagnet, Fig.
82. A t the end of the cock ing stro ke, the
release lever latches the t iming cam.
Dise ngag ing the release lever fr ees the timing cam. A spring then drives the tim ing cam in a counte rclockwise directi on. The timing cam both releases the opening blade and drives open t he trigge r switch.
The sp ring wh ich drives th e t iming cam co nnects to a spring-hooking tab on the bridge plate. Fig. 84. In the fir st Seiko shutters, such as th e model il lustrated, the spring-h ooking tab is a separate piece. A screw holds the spri ng-hooking tab to the bridge plate.
Afte r loosening the screw, you can
rot ate the spring-hooking tab to chang e the tension. Increas ing th e spring tension by turning the spring- hooking tab counter clockwise causes the timing cam to rotat e faster. The result? A signif icant change in the fast speeds.
But don't use the spring-hooking tab as
a shutte r-sp eed adjustment. Rather, on
reassembly, si mply return the spring-
hooking tab t o its original position, Fig.
84. Not ice th at Seik o uses a locking agent
on the spring-hooking ta b and screw. If
the screw works loose, the timi ng cam
loses its spring tension. Cons equently,
the shut ter won't release. In later shut
ters, Seiko made the spring- ho oking tab
part of the bridge plate.
If you don't change the in itial tension
on the tim ing-c am spring — and if you avoid disturb ing the trigge r-switch eccen tric — you may find that you don't have
to adjus t 1/1000 second. You can also visually set the blade tensions according
to the positions of the ratchets, Fig. 84.
Retur ning the rat chets to their proper
positions often brings in the blade-travel times witho ut fur ther adjus tment.
On reassembly, ro tate the ratchet s
clockwise to apply the initial tensions.
Locate the spring-hooking slots in the sides of the ratchets. Rotate the closing- blade ratc het until its sprin g-hooking slot just reaches the edge of t he bridge pla te.
Fig. 88. Then rotate th e opening-blade ratchet unt il its spring-hooking slot just passes the bridge-plate cutout.
Here's anoth er s hutter p roblem you may en count er — the blades won' t stay in the cocked position. First check th e spring on the release lever. Fig. 84. If th e spring comes disconnected, the release lever w on't latch the timing cam. As a re sult, the blades won't latch in the cocked position — the t iming c am immediate ly releases the ope ning blade. Th ere s hould
be a dab of Plio bond between the end of the sprin g and the release lever.
DISASSEM BL Y OF THE SEIKO SHUTTE R
Locate the two electromagnet lead
wires which connect to the shutt er-
terminal board. Fig. 82. Both wir es are the same colo r — normally white, but sometime s gree n or red. Unsolder both
wir es. Also unsolder the end of the trig
ger s witch from the shutter-circuit bo ard. Fig. 82. You'll probab ly find t hat it' s easier to unsolder the trigge r sw itch as you lift the shut ter-te rminal board from the bridge plate.
Remove the screw and lift off the
shutter-term inal board . On the back of
the sh utter-terminal board, you can see the X-sync contact. Th e lever which disengages the mechanical-speed latch for the mechanical 1/100-second ex
posure also strikes th e X-syn c contact to fire the fl ash.
Now dis enga ge the spring pawls to let off the blade tensions . Al so loosen the sc rew which holds the sp ring-hooking tab, Fig. 84. Al low the timing-cam spring to rotate the sp ring-hooking tab in a clockwi se direction. Then rem ove the screw a nd lift out th e s pring-hooking tab. If you 're wo rk ing on a la ter versio n of the shut ter, ju st disconnect the timing-cam spring from the tab on the bridge plate.
To replace the spring-hooking ta b, first locate the end of the timing-cam spring. Seat the spri ng-hookin g tab cl ockwise of the spring end. Then replace the s crew. Before you tighten the screw, r otate the spring- ho oking tab counterclockwise to
the positio n shown in Fig. 84.
There are two more springs to discon nect befo re y ou remove the bridge plate. Disconnec t the arm ature spring from the
bridge-plate tab, Fig. 86, and disconnect the spring from the release lever. Fig. 84. Now remove the remaining bridge-plate screws.
TENSION-
SETTING
RATCHETS
CA M SPRING
s
FLYWHEEL
Figure 89 Released position
Be careful as y ou lift off the bridge plat e — several shutter parts are loose, Fig. 89. In early shutte rs, you can lift out the loo se flywheel whic h engages the tim ing cam. Later models changed the fly wheel design; you can't take out th e later- style flywheel until you re move the timing cam.
Also lif t out th e timing-cam spring and the spring for t he shutter-release lever,
Fig. 89. Notice that the lower end of the timing-cam spr ing sits within a slot in the timing cam. The straight end of the spring for the shutter-release lever sits against a
pin on the magnet bridge, the plastic sup
port for the elec tromagnet.
Next lift out the two tension-setti ng
ratchets. The slots in the ratch ets fit over the upp er e nds of the blade-drive springs.
In earl y shutters, the pos ts passing through the cente rs of the blade -driv e springs are als o loose, Fig. 90. In later shutters, the po sts are formed on the rat
chet gears.
With t he loose parts removed, you can
safely op erate the shutter. Note the posi
tion of th e tri gger-switc h blade in Fig. 89. A washer holds the trig ge r-switch blade
on the magnet bridge. The upp er end of
the t rigger-switch blade connects to the
shutter-terminal board; the lower end
rests against the cam ridge of the t iming
cam.
Remember, the ti ming cam rota tes clockwise du ring the coc kin g cycle. Th e cam ridge then allows the trigger-switch blade to move from left to right, Fig. 90. So, with the shutter cocked, the trigger- switch blade moves against the eccentric pin on the bridge plate. The trigger s witch
now connects the orange-wire terminal of
the shutter-terminal board to grou nd.
In Fig. 90, you can also see how the timing cam drives the armatu re against
Figure 90 Cocked position
the e lect romag net . A roller on the ar mature rides again st the ou ter edge of the timing cam. As long as the timing cam re mains l atched by the shutter-release
lever, it holds t he arm ature against the
ele ctromagnet.
Dise ngaging the shutt er-re lease lever
allows the spring-loaded timing cam to
rotate countercl ockwise. A cu to ut in the oute r edge of the timing c am then frees the arm ature, Fig. 89. It's now up t o the electr omag net, the bulb lever, or the
mechanical-speed latch to hold the ar mature and prevent the closing blade
fr om releasing.
Also, the ridge on t he t imin g cam driv es the trigger-swit ch blade away from the eccentric pin. Disconnecting the trigger-switch blade f rom gr ound opens the trigger switch. Toward the end of the ro tation, the timing cam strikes the opening-blade latch to release the open ing blade.
On reassembly, rotate the timing cam to the released position. Fig. 81, before you replace the bridge plate . The trigger- switch blade then clears the eccentric pin.
But rotate the timing cam to the
coc ked po siti on, Fig. 90, to rem ove or to replace the t rigger-switch blade. Remove the trigger-switch blade by lifting off the insulating w asher. Notice that each end of the trigger-swi tch blade passes th rough a sl ot in the plastic magnet bridge.
Take out the b ulb lever by fi rst disc on necting its spring, Fig. 90. Then lift the bulb leve r up and off the magnet-bridge post. If you just wa nt to li ft off the magn et brid ge, you can leave the bulb lever and the remaining parts in place.
However, if you're replacing the elec tromagnet, also remove the timi ng cam, the armature, and the mechanica l-speed
latch. The replacemen t electr omagnet and t he magnet brid ge come as one assem bly.
Before you remove the magnet bridge, though, you migh t note one more timing point — that of the timing cam. Even if you leave the timing cam in place, it's possible to lose the timing. The timing cam may lift up slightly, thereby allowing
its pinion to dis engage from th e set gear, Fig. 91.
The set gear is the ge ar se gment under the ti ming cam. As you cock the shutter, a pin on the shutt er-cock ing lever co mes against the r ight-han d edg e of the set
TIMING
Figure 91
gear. The shutter-c ocking lever then drive s the set gear in a counte rclockwise dir ect ion. In turn, the set gear rotates th e timing cam clockwise.
If you h old the sh utt er-cock ing lever fully advanced, t he left-hand edge of the set gear c omes against a stop pin on the
magnet bridge, Fig. 91. T he timing cam
should now be in the position shown in
Fig. 91; notice th at the first tooth of the timing cam points to t he pivot p ost for the inertia fly wheel. If the timing isn't rig ht, lift the ti ming cam far enough to disengage the set gear. The n, with the set gear against the stop pin, position th e
MAG N ET BRIDGE
X-CONTACT CLOSING
LEVER
OPENING-BLADE DRIVE SPRING
Figure 92
timing cam as shown in Fig. 91.
You can now lift out the magnet bridge, Fig. 92. Also lift ou t the openin g- blade drive spring, Fig, 93. The longer end of the opening-blade drive s pring goes down and hooks against a tab on the opening- blade driving lever. Leave the clos ing-blade drive spring in place.
To remove the opening-blade latch, first disconnect its spring from the tab on the X-contact closing lever, Fig. 93. Then lift the ope ning-blade latch up and off its pos t. The spring stays on th e opening-
Figure 93
blade latch.
At th is poi nt, you ca n more easily
observe the operation of the blade assemblies. Be careful, though, that you don't lift up the bla de-driving levers. If you do, the pins on th e other sides of the
blade- driv ing levers will come out of the slots in the blade sets. Then, if the in
dividual blades shift in pos ition, you'll
have to realign the slots before you can
replace the blad e-driving levers.
Fig. 94 and Fig. 95 show how the
blade- driv ing levers operate. As you cock
the s hut ter, the shut ter-cocking lever comes against a roller on the opening- blade d riving lever (this roller is the part th at may be sheared off if the sh utter has been forced). The sh utter-cocki ng lever now push es up the opening-blade driving lever. In turn, the opening-blade driving lever pushes up the closing-blade dr iving lever. With the shutter cocked, the opening-blade latch, Fig. 93, engages the
opening-blade driving lever and the clo sing-blade latch, Fig. 95, eng ages the clo sing-blade driving lever.
Figure 94
Figure 95
I
SHUTTER-COCKING
LEVER ENGAGES
OPENING-BLADE
DRIVING LEVER
HERE
Figure 96 Figure 97
TRIGGER-SWITCH LEAD ------------
Figure 98
Simulate the release action by pulling
down the opening-blad e driving lever,
Fig. 96. As the opening-blade set moves down, it unc overs the apert ure. The sh utt er-cocking lever then latches and
holds th e ope ning -bla de dri ving lever,
Fig. 96.
Next disengage the c losing-blade latch
and pull down the clos ing-blade driving
lever. Wh en the closing-blade driving
lever reaches the position s hown in Fig. 97, it st rikes the latc h on top of the
On reassembly, leave t he shutter dry —
no l ubrication. Remember, oil quickly
works its way to th e shutter blades and to
the el ectrom agnet. Also, before you in stall the shutter on the mirror cage, you might double-check the operation of the trigger swit ch . Connect an oh mmeter
between the black-wire terminal, Fig. 81, and a metal portio n of the shu tter. With the shutter c ocked, you shou ld read
dir ect co ntinuit y. You should read infin ite
resistance wi th the shutter released.
opening-b lade driving lever.
Disengaging the latch frees the opening- blade d rivin g lever. The return spring then drives the opening-blade driving lever in a counterclockwise direction. And the open ing blade returns to the raised position, covering the focal-plane aperture.
T IMING CIRCUIT FOR ADJ USTING THE SEIKO SHUTTER
Earlier, we mentioned that you can
build a tim ing circuit for adjust ing the trig
ger swi tch. Just co nn ect the timing cir-
'cuit to the shutter's lead wires as shown
TRIGGER- SWITCH
1 ECCENT RIC
m ag ne t
LEADS
g r o u n d ]
.LEAD
Figure 99
in Fig. 98. There's only one problem — you disconnect the shutter leads to
remove the s hutt er.
If you're also removing the flex c ircuit, you can leave the shutter leads connected to th e s hutter-term inal boa rd, Fig. 98.
Disco nnect the other ends of t he wires from the flex. O therwise, yo u'l l have to temporarily solde r wires to the shutter- terminal board.
Then connect the test-circuit leads to
the shutter leads, Fig. 99. The magnet
leads connect to the two wires going to the electromagnet — red and b rown.
Now the test c ircuit supplies the power to
hold open the shutter. The tr igger-s witch lead connects to the wire going to the trigger switch, and the ground lead con
nects to any metal part of the shutter.
The trigg er-switch lead an d the ground lead now connect across the shutter's trigger switch. Remember, the trigger- switch eccentric pin is a ground co nnec tion. In some Seiko shutters, however, you'll find tha t the eccentric p in does not conn ect to ground. Instead, a separate wire goes to t he eccentric pin. In that case, con nect the trigger -switch lead of the test circ uit to one of the wires going to the trigger switch; conn ect the gr ound lead to the second tri gg er-switch wire.
W he n you now release the shutter, the trigger switch tells the timing circuit to start timing the exp osure . You can then use a sh utter-speed tester to measure the exposure time . The shutte r shou ld deliv er 1/1000 second with the timin g circui t connected. If not, simply adjust th e trigger-switch eccentr ic, Fig. 98.
The timing circuit in the test box
Figure 10 0
simulates the camera's timing circuit at the 1/1000-second s etting. There are several ways you can build such a timing circuit. Fig. 100 illustrates one me thod. Yo u should have no trouble in obtaining the com ponents from any elec tronics sup plier.
A lthough you could bu ild the power su pply into the test box, we' ve designed the circuit of Fig. 100 to be used with a separa te 3V DC power supply. Notice that the magnet lead connect s to the col
lector of a swit ch ing tr ansistor. A com parator controls the signal at the t ran
sistor base. When the o utput of the com
parator g oes high, t he transistor sw itches on. Th e transist or then conducts current th rough the shut ter's electromagnet.
The trigger switch of the shutter con
nects to the timing capacitor of the ti ming circuit. With the shutter cocked, the closed trigger switch shorts the tim ing capacitor to ground. Then, when you release th e shut ter, the trig ger switch opens and allows the timing ca pacitor to start charging.
W he n the timing capacitor reaches the
reference voltage, the compara tor swit ches states — the o utp ut goes low to shut of f the transistor. In turn, the tran sistor shuts off the current through the shutter's electromagne t. In Fig. 100, we've provid ed a variable-re sistor adjust
ment to establish the referen ce voltage at the noninverting i nput of the c omparator .
Use th e v ariable resistor to adjust th e t im ing circuit for 1/1000 second.
Figure 1 01
We've also provided a seco nd speed in
Fig. 100. As men tioned earlier, the slower shutte r-spee d setting serves as an opera tio na l check. You may wish to set the second speed for 1/100 second, the full- aperture speed. That wa y, you ca n also use the test box for checking X-sync operation .
Rather than the compa rator IC, you
may prefer to use a tw o-transistor switch
as shown in the inset, Fig. 100. Connect the base of the second transistor to the timing capa citor. By using a variable resistor to control the cap acit or-c harge tim e, you can adjust the t est cir cuit for 1/1000 second.
SWITCH
ADJUSTING THE RELEASE SWITCH A ND THE MET ERING SWITCH
There 's another reason fo r remo ving the shutte r — to reach the release swi tch S3 and the meterin g sw itch S5, Fig. 101. Earlier, we described how yo u can check the two switches wi thout disassembly.
However, if y ou pinpoint the proble m to one of the swit ches, lift aside the shut ter to make the repair (you don't have to disconnect th e shutter wires to ad just and clean the swit che s).
A sl iding brush contact. Fig. 101, closes both switches as y ou depress the release slide. The brush firs t connects the gre en- wire land to ground, thereby clos
ing the metering switch S5. Next the brus h connects the oran ge-wire contact to ground to close the release s witch S3.
As noted during the trouble shooting, suspect S5 if pushing the release button part way fails to turn on the LED display. Su spect S3 if the shutter w on' t release at the electronic settings. You can now clean th e brush contact and th e switch board lands.
But, if you remove the switches for cleaning, you'll have to readjust the s witch board. Adjust the switch timing by first loosening the two screws — one holding
the brush and one holding the switch board, Fig. 101. Then shift the position o f the switch board to set the amount of release-slide movement needed to close each switch.
Check the metering switch S5 first. Connect an o hmmeter betwee n the green wire and ground. Then slowly depress the release bu tton. When the release slide moves d own 0.4mm, the metering switch should clos e. Your ohmme ter should then show direct continui ty between the green wire and ground.
To check the release switch, make sure you've set the speed knob t o an electronical ly controlled speed. Then connect your ohm meter between the orange wire and ground.
The release switch should close when the
release slide moves down 1 mm.
Double -check the switch timing by set ting a mechanical speed — 0 or B. Th e
release-slide latch now moves out of the path of the release slide. As the brush starts to rotate clockwise, the release-slide latch blocks th e switch arm, Fig. 101.
The bru sh should still rotate fa r enough to close the metering switch. However, the release-slide latch should block the brus h rotatio n before the release switch closes.
So, with your ohmmeter connected bet ween the orange wire and ground, depress the release button. The release switch should not close — no matter ho w far down the release slide moves. T hen chec k t he mete ring switc h between the green wire and groun d. The met ering switch should close whe n the release slide moves down 0.4mm.
REMOVING THE FLEX CIRCUIT
Oth er than f or replacement purposes, there aren't too many reasons to remove
the fl ex circu it. The complete flex circuit does c ome as a repla cem ent pa rt (flexible circuit base plate, A set — 0841). A
repla cement flex includes the RTV
(shutter-speed) resisto r, b ut not t he dia phragm resistor or the SPD board . There's also an ex chang e prog ram . If you send in the old flex circuit, you can get the replacemen t for about half price.
Fig. 102 shows the wiring pic torial for
the flex circuit. If you kn ow bef orehand that yo u're going to remove the flex cir cuit, leave t he shutter in place. You can
then disconnect the shutter wires f rom the fle x circu it rather than from the shutter-terminal board. But watch for w iring variation s. In earlier versions of the flex circ uit, you'll fin d slight variations in the physical posit ions of the wires.
The wires from the shutter-terminal board, the release switch, and the meter ing switch pass thro ug h the flex-circuit slot. Uns older t he green S5 wire, the orange S3 wire, the red magnet wire, the br own m agnet wir e, and the black trigger-swi tch wire. Als o unsolder the two gray wires f rom the syn c p in, Fig.
102. It's not necessa ry to unsolder the blue wire t hat passes throug h the flex- circuit slot; the blue wi re connects S11 to pin 12 of IC1.
Now unsolder the seven connecti ons to
free the flex st rip of the diap hrag m
resistor, Fig. 102, and unsolder the four wires at the si de o f the mirror cage — blue, orange, p ink, and vi olet. Also, if yo u'r e replac ing the flex circuit, unsolder the wires that connect the SPD board to the flex, Fig. 102. Unsolder the wires from the flex, not from the SPD board. Discon nect the SPD board from the flex by un soldering the c onnection shown in Fig.
103. However, if yo u're not replacing the flex, leave the S PD board c onnect ed — you can remove the flex and SPD board as a unit.
To remove the speed selector, yo u’ll
have to d isconnect the tungs ten wire t hat
FLEX-ST RIP CONNECTIONS
BRO W N - M 3
BLACK - S4
SPD BOARD
GRA Y-X CONTACT
Figure 102
co ntrols the shutter-s peed scale. First set the 0 shutter-speed setting, Fig. 103; that
lets off most of the initial tension. Remove the speed knob and unscrew the nut holding the speed select or. Then, as
you lift off the speed sele ctor, disconnect
the tungsten wire from the ad justment collar, Fig. 103. Careful — the ball detent and compre ssion spri ng for the speed selector will be loose. We'll describe the procedure for reconn ecting the tungsten wire during reassembly.
Now take out the two screw s holding the pull ey bracket, Fig. 103. Watch for the loose spacer under one end of the bracket (the end closer to the back of the camera). Now lift out the mask lever. Fig.
103, and disconnect t he wire link that runs be tween th e mask lever and the
viewfinder mask.
Remove the complete flex circuit by taking out the two screws h oldi ng the
RTV resistor, the two screws h oldi ng the SPD board , and the two ground screws at the side o f the mirror cage . At the back of th e flex circuit , you can now see th e
LED display and IC2, Fig. 104.
If you just want to c heck IC2, you can reach the IC without completely removin g the f lex circuit. Take out the two ground
screws at the side of th e m irro r cage. Then lift th e LED base plate, Fig. 104, far enough from the mirror cage to reach the
IC. Supp ose, for examp le, that you 're ge tting n o LED readout..You might check
for 3V at pin 2 of IC2, Fig. 104, with the
release butt on partially depressed.
Figure 103
It' s also possible to check the individual LEDs with out rem oving the flex cir cuit co mp letely. Fig. 104 points out the hole that receives the ground screw. Connect a jumper between t he groun d land at th e othe r side of th is hole and the front plate. Then push the release button part way to supply the LED anode voltages.
If you now short between a cathode lead and gro und. Fig. 104, the LED con nected t o that outpu t should turn on.
Wh at if it doesn't? The particular LED may
not be getting the 3V anode vo ltage (you can check the anode volta ges a fter remov ing the plastic cover over the LED display).
Or the LED may be defective . However, you can't get the LED base plate as a separate part. A defe ctive LED requires replacing the c omplete flex circuit.
Fig. 105 shows the t op of the shut ter/
mir ror-cage assem bly after removing the flex cir cuit. Notice that the spee d-control cam is now loos e. In Fig. 105, you can see how the speed-con trol c am position s the mech anical-spe ed lever (the leve r t hat cont rol s the s hutter' s bulb lever). A pin on the mechanical-speed lever rides against the speed-control cam. The pin on the underside of the speed-control cam positions t he release-slide latch.
MIRROR-CAGE REPAIRS
For most of the mechanical repairs on the mirror cage, you don't have to remove either t he fl ex circuit or t he shut ter. In fact, you may not even have to remove the mirror cage from t he body casting. I f the pr oblem is in the air cylinder or the memory-ti me-lag adjust-
HOLE FOR GROUND SCREW
LED BASE PLATE
Figure 104
LED DIS PLAY
Figure 105
WIRE CLAMP
SPEEDCONT ROL
MECHANICAL- SPEED LEVER
ment, you can usually make the repair
without pulling the mir ror cage.
Earlier, we m ent ioned that the air piston on th e side of the mirr or cage pro vides the memory time lag. The air piston actually releases the mi rror. When the mirro r-release mag net diseng ages the mirror-release lever. Fig. 106, the sp ring- drive n piston moves down. The piston then disenga ges the mirror-lifting lever.
Yo u ca n adjust the memory time lag by
turni ng the setscrew at the top of the air
cyl inder, Fig. 107; you don't even have to
rem ove the mirror cage to reach the ad
ju stment. Turning down the setsc rew in
creases the pressure of the spring inside the cylinder. The spring th en dri ves down the piston more quickly, resulting in a shorter delay bet ween the closing of t he
release switch and the opening of the memory swit ch.
The time dela y assures that the dia phragm reaches the taking ape rture before the me mor y switch o pens. Minolta
AD J U S T M E N T SET S CR E W
specifies a 56ms delay bet ween the two swit ch ing actions. Too short a memory time lag res ults in inaccura te exposures; the memory switch ope ns before the diaphragm has time to reach the s elected aperture.
You may never have to adjust the memory time lag. But, in some situ ations, you may be able to trace the pro blem to the air cyl inde r. For example, if the owner shoots pictures a t high altitudes, the decreased air pressure within th e cylinde r
Figure 106
Figure 10 8
AIR CY LIND ER
Figure 107
TENSIO NI NG -LE VER LATCH
Figure 109 M irror charged
SC R EW S HOLDI NG AIR CYLIND ER
DIA P H RA G M - CLOS IN G LEVER
Figure 110 Mirror up
Figure 111
may allow the pist on to move too quickly. Since the m emo ry time lag is then too short, the owne r gets inaccurate or er ratic exposures at au to. Yet, at normal altitudes, the camera t ests perfe ctly.
Dirt in the air cylinder can also cause problems — even a failure of the mirror to release. Y ou can remove the air cylin der
for cleanin g withou t taking out the mirro r
cage. Just remove the tw o screw s hold ing the air cylinder ; reach the screws through the cutout at the side of the lens mount, Fig. 107. But be careful — both the air piston and the compres sion spring inside the c ylinder will be loose. After you clean the parts, wip e th e inside of the air cyl inder wi th a thi n coat of shutter oil.
In an earlier Craftsman article, we described the tech nique for measu ring the memory time lag using an os cill o scope. The technique inv olves connect ing the vertical inp ut of the s cope be tween the release s witch and the mem ory switch. Also shor t ac ross the memory cap acitor. When you then release the sh utter at the X set ting, you can measure the length of time that the trace sta ys at OV — that's the mem ory time lag.
But you don't have to rush out and buy an oscilloscope to repair the XD-11 . For one thing, adjusting the memory time lag is n't a common repair. And, if necessary, you can adjus t the m emory time lag by making repeated auto-exposure tests. Remem ber, an in accurate memory time lag causes erratic and incorrect expo sures. So, by tu rning the setsc rew, you can change the memor y tim e lag unti l the
auto e xposures are consistent and cor rect. If you d o turn t he setscr ew, Fig. 107, lock the adjusted pos itio n with cement.
The more common mechanical repairs
involve the levers at the bottom of the
mi rror cage, Fig. 108. For example , you
may find tha t the camera works proper ly wit h the lens removed. However, as s oon as you install the lens, the camera jams. Wha t happens is that the diaphra gm fai ls
to reopen af ter the exposure — usually
because the mirr or- ten sioning lever, Fig.
108, isn't mov ing freely.
In Fig. 108, we've removed the two com bination magnets at th e bottom of the mir ror cage. Remember, though, that remov
ing the combin ation magnets requires that you readjust their positions on reassembly. You can now see the diaphragm-control parts.
The mi rror-tens ioning lever mov es to
the charg ed posit ion, Fig. 109, when you cock the shutter. N otice in Fig. 109 that the tensio ning-lever latch now engages
the mirro r-tens ioning lever. The n, when
the mirror-release magnet disengages the
mirro r-release le ver, Fig. 106, the
diaphragm-closing link pulls the
diaphrag m-clos ing lever from right to left.
Fig. 110.
Also, the diaphragm-closing lin k ro tates the gear segment, Fig. 110, in a co unterclo ckwise direction . The gear seg ment then turns the rat chet gear (remain ing with the diaphragm-control magn et). Stoppi ng the ra tchet gear arrests the move ment of the gear segm ent. In turn, the gear segment stop s the travel of the
diaphragm-c losing link.
Af ter the expo sure, the shutter mechanism pushes down the mirror- return link, Fig. 106. The mirror-return link n ow disengages the tensioning-lever latch from t he mirr or-tensioning lever, Fig. 108. As the m irror-tensionin g lever moves clockwise, it drives the diap hragm- closing link back to its original positio n.
So, if the diaphragm won't reopen after the expo sure, suspect the mirror- tensionin g lever. Dirt may be preventing free travel. As a result, the mirror - tensionin g lever ca n't push the diaphragm- closing link against the spring t ension of the lens.
For m ajor repairs, y ou may have to separate the mirror cage from the fr ont plate. Take out the two upper mirro r-cage screws, Fig. 111, and the large screw at the bottom of t he mirror cage. Then sepa rate the mirror cage from the front plat e.
You can now get a b etter idea as to the
mirror-rele ase a ction. Notice in Fig. 112
ho w the memor y-s wit ch lever latches the
mirror-lifting lever. The damper link now
holds the air pisto n within the air cylinder — against the pressure of the compres
sion spring.
When the mirror-relea se lever frees the diaphrag m-closing link, i t also frees the dampe r link. The spring-loaded piston then moves do wn, driving the damper link in a clockwise direc tion, Fig. 113.
Now the dam per link strikes the mem ory-s witch lever, Fig. 113. As the up per end of the memory-switch lever swings towa rd the back of the mirror
Figure 112
Figure 113
SPRING -LOAD ED PULL EY
Figure 114
WIRE-HOOKING
PULLEY
cage, its insulator opens the memory switch. Also , the latchin g end of the memory-switch lever disengag es the mirror-lifting lever, Fig. 112. T he mi rror- lif ting leve r then drives the mirr or to the
raised position.
W he n the mirror nears the ta king posi
tion, the shutter-release lever, Fig. 106,
move s down to release the shutter . The
shutter-r elease lever has a slidin g adjust
ment; af ter loos ening the two screws, you can slide the shutter-release lever up or down . If you move down the shutter- release lever, the mirror doesn't have to rise as far befor e releasing the shu tter. Movi ng up the shu tter-release lever means that the mirror must rise further to release the shutter.
You can check the ad jus tment after you replace the shutter. Hold down the mi rror as you depress the release b utton at a mec hanical se ttin g. Then allow the mi rror to mov e up sl owly. The shutter should release when the mirror moves 2/3 of the way to the taki ng position.
Fig. 106 points out one other adjust ment — the self-timer eccentric. You can use the eccentric if the self timer fails to pull down the release slide far enough to release the shu tter.
Figure 115
PULLEY #2
PULLEY #1
TIMING THE SPEED SELECTOR
On reassembly, it's possible to replace the speed selector 180° out of time. Two tabs on the und ersid e of the speed selec tor key t o two slots in the top of the speed-control cam, Fig. 105.
Start b y turni ng the speed-control cam to a mechanical-speed position. You can tell whe n you're at one of the mechanical speeds by noting the position of th e release-slide latc h. Wh en the release-slide latch moves away from the release slide, the mechanical sp eed-control cam is at either bulb or 1/100 second.
Then seat the speed selector with its detent notches position ed as show n in
Fig. 103. The speed selector drops in to place when its two tabs pass into the two slo ts in the speed-con trol cam.
REC ONNECTING THE TUNGSTEN
WIRE
Assemble the front-plate/mirror-cag e
asse mbly to the camera body before you
recon nect the tungsten wire. Then s et the speed selector to the 0 po sition — ful ly clockw ise.
With the tu ngsten wire disconnected, there's very litt le tension on the spring- loaded pulley, F:g. 114. But the sprin g tension increases as the scale wraps onto the wire-hooking pulley. Be caref ul, then, th at you don't ac cide ntally release the
wire-hooking pulley with any amo unt of
spri ng tensi on on the s pring-hooking pulley. Too m uch tension could break the scale.
You can get jus t the shu tter-speed
scale as a replacement pa rt. Alte rna tely, you can replace the complete shutter-
speed indicator a ssembly ; the assembly includes the scale and the pulleys with the spri ng already tens ioned. Ther e's an ad vantage in replacing the complete assembly — if you replac e just the scale, you may e ncounter tracking and a lign ment problem s. T hat is, when you get the "0" calibration centered in its window , you may fin d that the ‘‘1000'' c alib ration does not center. However, if the scale breaks, you can normally make a satisfac tory rep air without replacing parts.
The break usually occurs at th e p oint
where t he scale c ements to t he wire-
hooking pulley. Part of the scale then re mains cemen ted in place. Simply butt the loose end against the end still attac hed to the pulley. Then cement the loose end
with super glue.
Now sl ip the kno t in one end of the
tungsten wire t hrough the slot in the
wire-hooking pulley, Fig. 114. Wrap the
tungsten wir e 2-1/2 turns around the wire-hooking pulley in a clockwise direc tio n (as seen from the back). It's a little tough to wrap the free end of the tung sten wire a round the w ire-hookin g pulley
— yo u don't have a lot of room. But there's another technique you m ay find to be easier. Before you connect the tungs ten wire, rotate the wire-hooking pull ey fully clockwise (as seen from th e back). The scale then wraps around the
w ire -hooking pulley, adding tension to
the spri ng.
Next, while holding th e wire-hooking pulley to maintain the spri ng tension, co nnect the tungsten wire. You may have to allow the wire-hooking pulley to rotate
slightly counterclockwi se until you can
reach the s lot. If you need both hands t o co nnect th e tungsten wire, you might use
a piece of masking tape to hold the spring-loaded pulley in place. Here, it's crit ical that you don't accidentally release the pulley s. With so much tension on the spring, the scale would definitely break.
Aft er you connect one end of t he tung sten wire, hold the ot her end as sh own in Fig. 115. Now let go of the spring-loaded pulley and a llow the spring to sl owly dra w the scale from right to l eft. The tungsten
wire should wra p itself t wo turns around
the wire-hooki ng pulley. Y ou need then
wr ap on only 1/2 additional turn.
You may wis h to put a piece of mask ing tape over the wire- hooking pulley to keep the tungsten wire in place. Then route the tungsten wire under pulley #2,
Fig. 116. Notice in Fig. 116 that we've temp orarily repositioned the flex circuit to clear pulley #2. Norma lly the flex covers part of the pulley, Fig. 117.
With the flex repositioned, you can
more easily r oute the tung sten wire be
tween the p ulley and th e tab, Fig. 116.
Finally, wrap the tungsten wire in a
clock wise direction around t he adjust
ment c ollar, Fig. 117. Push the knot ted
end through the top of the hole in the ad
justment collar and seat the tun gsten wire
within the screwdrive r slot.
Only one step remains — adjusting the
position of the speed-indicator scale. As you look through the finder, rotate the ad justment collar in a clockwise direction . The clockwise rotating draws the scale from left
to right, Fig. 117. Continue tur ning the ad justment collar unti l the "0" calibration aligns in the viewfinder window.
Figure 117
Figure 118
TRAN SPORT REPAIRS
There 's one common repair in t he transport — replacing the take- up spool. You may find that the gray section at the botto m of the take -up spool has broken loose. Or, more f requen tly, the owne r has broken off all four of the film-hooking lugs.
The o wner breaks the lugs by attempt ing to squeeze on extra frames at the end of the roll. B y forcing the wind lever, he breaks off the lug which ho oks the film.
He th en uses another of the four lugs. When none of the lugs remains, he brings in the camera for repair.
To replac e the take-up spool, you must remove the wind seat, Fig. 118. The springs connected t o the advanc e- indic ator lever. Fig. 118, th en com e disconnected. You can remove the wind seat and the coun ter dia l as one u nit.
ADVAN CE- INDICATO R
STOP SCREW
Figure 119
Figure 120
TRANSP ORT CAM
PAWL
SPRING
Figure 121
FILM -ADV ANCE IND ICA TOR
LEFT -HAN D SCREW
ADVANCE-INDIC ATOR LEVER
WIND- RATCHET PAWL
TRANSPORT-RELEASE
LEVER:R /
However, you'll fin d it easier to rec onn ect the springs if yo u first re move the counter dial.
Take out the screw holding the counter stop, Fig. 118. The counter stop serves both to co nnect the counter-dial spring and to stop the counter dial at the "S "
position. Lift out th e counter dial and the
counter stop as one-assembly.
Fig. 119 shows th e t op of the wi nd seat
with the counter dial removed. No te the
two springs which connect to the tab on the advance-i ndicator lever. The larger spri ng rotates th e advance- ind icator lever in a clockwise direct ion. But, as the film winds on to the take-u p spoo l, it pushes aga inst the sensing lever inside the take- up-spool ca vity. The sensing lever at tache s to the advance -indicato r lever. So, as the sensin g lever moves toward the front of the camera, the adv ance-in- dicator lever rotates in a counterclock wise direction.
The smaller of the two sprin gs, Fig.
119. now pulls the film-a dvance indic ator counterclo ckwise. One end of the smaller spri ng connects t o th e ta b on the advance-indicator lever; the o ther end hooks to the si de of the film-advance in dic ator.
Both sp rings remain with the wind seat. Take out the two wind-seat screws . Fig. 119. Then lift out the wind seat. Watch for a loose endplay spacer on the to p of the w ind shaft, Fig. 120; not all cameras use the endplay spacer. Also, if you removed the wind lever, the wind cam passing thr ough the wind-seat bushing will be loose.
Next lift ou t the wind-ratch et pawl, Fig.
120. The post on the und erside of the wind-ratchet pawl fits between the two ends of the pawl spring. Then, f ro m the bot tom of the body, disc onnect and
remove the two springs that hook to the
tab of the t ransport-release lever, Fig.
121. Th e up per spring provides the ten
sion which moves the transport-release
lever toward the front of the camera; the gold spring serves both as the power-
w inder switch and as the spring for the
transp ort l atch.
Remove the trans port- relea se lever by tak ing out its screw, Fig. 121. Watch for the loose bushing under the transport- release lever. Th e s hou lder o f the bush ing goes down, passing through the slot in the m irror-cocking lever.
Also take out the screw ho lding the shutter-c ocking lever and the left-ha nd scr ew holding the t ransport cam, Fig.
121. Before you lift out th e transport cam, note the posit ion of the adva nce-pawl spr ing, Fig. 121. Th e sho rt end of the spri ng connects to a tab on the advance pawl; the long end connects to a tab on
the lock plate, a part under th e transport cam. Just to be safe, you might disc on
nect and remo ve the advance- pawl
spring.
Now lift out the transport cam tog ether with the mirror- cocking lever and the shutter-c ocking lever. Fig. 122 poi nts out
the lock plate mentioned earlier. The dow nward-projecting tab on the lock plate comes a gain st the end of the wind latch.
Lift out the lock plate. Th en, from the
top of the body c astin g, lift the wind shaft high enough to disconnect the end of the
w ind- shaft spri ng. As you lift o ut the
wind shaft, watch for the loos e bushing that fits into the top end of the take- up spo ol. Fig. 123. The bushin g nor mally stays with the wind shaft as shown.
To remove the take- up-spool assembly,
Fig. 123, you must firs t take out the winding-ba se plate, Fig. 122. Remove the two scre ws. Then lift ou t the winding- base plate, the assembly that contains t he two wind gears and the latches.
The take-up-spool gear may stay on the
underside of the winding-ba se plate. Or it
may stay in the bottom of th e body cas ting. Two tabs on the u nders ide of the tak e-up-s pool gear engage the slots in the tak e-up-s pool shaft. Lift out both the tak e-up-s pool gear and the sprocke t gear at the bottom of the body casting. Watch
for a was her on top of the sprocket gear.
You can now remove the take-up spool
from the back of the body casting, Fig.
123. The take-up spool has three s ectio ns
— the center shaft which includes the slip
spring, the plastic spool (the section that
breaks), and the bearing whic h sits
shoulder up on top of the plas tic spool. When you order a replacement, you'll get
both the plastic spool and the cen ter
shaft.
Figure 122
WIND -SHA FT
BUSHING
SLIP SPRING
TAKE-UP
SPOOL
2005-0332-11
REMOV ING THE SPROCKET
To take o ut the sprocket, first remove the counter-advanc e assembly, Fig. 124; the base plat e of the assemb ly also serves as the upper bearing for the spr ocket.
Rem oving the counter-a dvance assembly loses the timing of the counter actuato r, the black rod running through the bush ing of the back-sen sing lever.
The camera back pu shes the back- sensing lever countercl ockwise. As a result, the back-sensing lever bring s the co un ter actuator a gainst the gear on the underside of the counter dial. As the
sprocket rotates, it tur ns the counte r ac tuator. Then, when the notch in the counter actuator comes against a count er-dial tooth, th e counter dial ad vances one film-frame calibration.
Since the sprocket drives the counter
Figure 123
Figure 124
BACK-SENS ING
LEVER
COUNTER
A CTUATOR
HOOKING
SCREW FOR
WIND-SHAFT SPRING
j
dial, you always get an accurate in dication
— even though you may shoot double ex posures. The double-exposure feature in the XD-11 just disengages the advance pawl, Fig. 121, from the main wind gear. Fig. 122, w hen you push dow n the re wind
button. Pushing down the rewind button
moves the long end of the rewind -bu tton
latch, Fig. 122, aga inst the advance pawl.
The timing we mentioned refers to th e position of the notch in the counter ac tuator, Fig. 124. We 'll de scribe the pro per timing during reassembly. Although you can remov e the counter-advance assem bly as a unit, it's easier to retime the counter actuator if you remove the back- sensing lever, Fig. 124. Disc onnect and remove the spring on top of the bac k- sensin g lever; notice t hat the short end of the spring connects to t he snap ring w hich holds the b ack-sensing lever in place. No w remove the snap ring and the spring. Lift out the back-sensin g lever together with the counter actuator.
Also lift ou t the two plastic gears on
top of the base plate, Fig. 124. The smalle r gear has a slot wh ich fit s over the flat si des of the sprocket rod. Remove the
base plate by tak ing out the cross-point
screw.
Three p arts inside the sprocket are n ow loose — the compression spring and two
brass washers. You can rem ove the se
parts more easily after you take out the spr ock et. Remove the screw holding the lower sprocket bearing at the bottom o f the body casting. Then lift out the sprocket from the back of the camera.
REPLACING THE SPROCKET
One end of the sprocket has slots to receive the pin through the sprocket sh aft. Seat the sprocket wi th the s lotted end down. Then replace the sprocket shaft and the low er sprocket bearing.
Now, f rom the top of the body, place one of the brass washers over the top of the sprocket rod. Seat the comp ression
spri ng next. Final ly, place the second brass washer on top of the compression spring.
Replace the base plate, Fig. 124. You'l l
notice that the base plate has a sliding ad justment; by loose ning the cross-poi nt scre w, you can shi ft the base plate in
position. The slidin g adjus tment p ermi ts you to adjust th e engagement of the counter act uator wi th th e counter-dial gear. You can make the adjustment after you replace the count er dial.
Now, as you replace the back-s ensing
lever, you can time the cou nter actua tor.
Fig. 125 sh ows the proper position of the
no tch. Se at the two plastic gears on the
base plate. Then insert the cou nter ac
tuator int o the hole in the ba ck-sensing lever. Rotate the counter actuator to the po sition shown in Fig. 125 and mou nt the back-sens ing lever on the base plate.
Check the posi tion of the counter ac tu ator before yo u replace the sna p ring. If the notch isn't in the proper position, lift the back-sensing lever high eno ugh to disengage the counter ac tuator . The n tu rn the counte r actuator to the position show n in Fig. 125.
The n replace the spring for th e back- sensing lever. Also replace the snap ring and connect the short end of the spring as shown in Fig. 124. Check the assembly by rotating the s pro cke t; the counter ac tu ator should turn freely.
Figure 125
SPROC KET TIMING
Proper sprocke t timing assures that the spaces between film frames also fall be tween per foration holes. Most customers
would never notice an error in the
sprocket timin g. However, some types o f slide mounts depend on p roper fi lm reg istration; pins on the slide mounts fit through the perfora tion ho les to hold the film.
To check the sprocket timing before disass embly, just rotate the sprocket toward the rewind side to take up the
backlash. The sprock et teeth should th en be positioned as shown in Fig. 126. Or, if you're n ot sure o f the proper sprocket po sition , load a roll of test film. Then ho ld open the s hutte r on bulb. Using a p encil, trac e around the edge of the focal-pl ane apertur e to draw th e frame position on the film. You now have a picture of the frame posi tion on your test roll. The film draw ing in Fig. 126 shows where the frame should be in relation to th e perfora tion holes.
You can time the spr ock et after you remo ve the winding-base plate. So, before you replac e the winding-base plate, rotate the sprocket to the proper ly timed position, Fig. 126. Remember to take up the backlash by rotating the sprocket toward the rewind side o f th e camera.
REPLACING AND TIMING THE WI NDING-BASE PLATE
There's one precaution as you seat the take-up spool - mak e sure the sensing lever for the film-adva nce indicator is
aga inst the f ront of the body casting. The sensing lever must ride between the take-
up spool and t he fro nt of th e camera.
Then replace the take-u p-spool gear and
the sprocket gear at the bottom of the bo dy castin g.
Now locate the pun ch marks on the top
surfaces of the main wind gear and the sec ond gear, Fig. 127. B efore you seat
Figure 126 Sprocket position as seen from bottom of camera
Proper film registration
the winding-ba se plate, rotate the main
w ind gear unti l o ne of its p unch marks
aligns with the punch mark on t he second gear. The wind latch should then be against one of the thr ee lugs on t he ma in w ind gear, Fig. 127.
Seat the winding-ba se plate and recheck the sprocket timing. Wh en you rotate the s pro cke t towar d the rewind end of the camera — thereby bringing the wind-gear lu g a gainst the wind latch, Fig. 127 — the sprocket tee th s hould be posi tioned as shown in Fig. 126.
After replac ing the screws to hold the wi nding -base plate, sea t the wind shaft . You'll have to hold the wind-shaft spring aga inst its tension t o connect it to the body-casting screw. Then complete the reassemb ly at the bott om of the camera
— seat the lock plate, Fig. 122, replac e the transport cam , and reco nnect the springs, Fig. 121.
REPL ACING AND ADJUSTI NG THE COUNTER DIAL
Replace t he wind-ratch et pawl and the
wi nd seat. Then reconnect the springs to
the advance-i ndicator lever as shown in
Fig. 119.
Now seat the count er dial and the counter stop as one assembly. B ut, before yo u replace the screw that holds
the counter stop, ap ply the initial tensi on to the count er sprin g. Just rotate the counter dial one tu rn in a clockwise direc tion. Swing aside the counte r stop and
rotate the counter dial to the start posi
tion — un til the "S " points to the end of the camera, Fig. 118. Then move the counter stop into engagement with the stop tab on the counter gear and replace the c ounter-stop screw.
The "S " on the counter dial should re main aligned as shown in Fig. 118. If the
"S " appea rs off- center, it w on't align wit h the index on the top cove r. You can then adj ust the start position by bending
the upper lug on the counter stop. To be
sure of th e prop er align ment, you might temporarily replace the top cover. Check to see that the "S " aligns wi th the top- cov er index.
Next replace the camera back and
check the op era tion of the co unte r ac tuator. As you close th e camera back, the coun ter ac tuator sho uld mov e into the slot between the first and sec ond teeth of the counter gear, Fig. 125. I f the counter actu ator doesn't align with th e t ooth slot
— and instead com es against one of the
gear teeth — you'll see the counter dial shift in p osition as you close the camera back.
Adjust t he align ment of th e counter ac
tuator b y shifting the base plate of the
counter-advanc e assembly. Fig. 124. Just
loosen the screw an d move the base plate until the counter act ua tor align s with the first tooth slot.
OTHER TRANSPOR T ADJUSTMENTS
If t he film fails to transport, suspect the adju stme nt on the wind latch, Fig. 128. At the en d of the cocking cycle, the wind
latc h should drop into engageme nt with a
lug o n the main wind gear. How ever, if the wind latch fails to engage a lug, the film can turn the sproc ket in the reverse dir ection.
Check the action by using your finger to put reverse pre ssure on the sprocket as you cock the shutter. You should see the wind latch drop into engagement sli ghtly
before the wind-r atchet p awl. Fig. 120, dise ngages from the teeth of the wind shaft.
You should then find that you c an't
turn the sprocket in the reverse direction
— the wind latch prevents reverse r ota
MAIN WIN D PUNCH MARKS GEAR
Figure 127
ECCENTRIC FOR ECCENTRIC FOR POWER-WINDER SWITCH RELEASE BLO CKING LEVER
WIRE TOUCHES POWER-WINDE R BUSHING HERE
WI ND-LATCH ECCENTRIC
Figure 128
tion. To adjust the w ind latch, loo sen the scr ew and turn the eccentric brass
bushing, Fig. 128.
Also no te the two ecc entr ics on the
tran spor t latch, Fig. 128. One eccentric
cont rol s the position of the release- blocking lever, the lever tha t prevents you
fr om pushing down the release slide dur
ing the cocking strok e. The release- blocking lever sits under the transpo rt latch .
Check t he a djustment after partially co cking t he shutter. With the transport latch riding against the smooth , outer surface of the transport cam, the release- blocking lever sho uld be over th e lower end of the release slide. The release- blocking lever then preve nts you from depressing the release button. By t urnin g
the ecce ntric. Fig. 128, y ou can reposition the relea se-blocking lever. Turn the e c
centric until the release slide appears right in th e center of the release-blocki ng lever
with the shutter partially cocked .
The other eccentric on the transport
latch controls the position of the power- wi nder swit ch . To check th e adjustment,
again partially co ck the shutter. Wi th th e transp ort latch against the outer edge of the transport cam, the gold spring should come against the ed ge of the power- w inder b ush ing. Fig. 128. Tur n the brass eccentric so that it just touches the gold wire.
Now complete the cocking stroke and
allow the wind lever t o return slowly.
When the tr ansport latch dro ps into
eng agement with t he first step in the transp ort cam, c heck the position of the gold wire — the gold wire should com pletely clear the hole in the power-wi nd er bushing. ■
CONCLU SIONS ON THE XD-11
Some tec hnicians have comp laine d
that the modern generation of electronic
SLRs can't provide the ruggedness and
versatility needed by professional
photographers. N ot so the wit h XD-11.
The XD-11 can withstand just abou t any
punishment a pro can dish out . Plus it of fers the vers atility of every possible opera tional mode.
As on e example of the durability , we
recently received an XD-11 which had take n a spill off a motorcycle traveling 80mph. The impact made a mess of t he top cov er and the rewind knob. Yet the
camera still worked!
The versatility comes fro m the choice
between manual operation, automatic shutter speeds, or a utom atic diaphragm
openings. The re's also a thi rd mode, one
not pu blicized — fully p rogr ammed op eration. In the S mode, the XD-11 sets the diaphragm opening an d, if necessary, changes the shutter speed automatic ally. You can t hen leave the speed knob at the
1/125 set ting in the S mode. The XD-11
uses the 1 /125 shu tte r speed i f it can.
But, if 1/12 5 won't produce the proper
Summary of troubles hooting:
exposure, the XD-11 selects the shut ter speed it needs.
A nothe r of the XD-1 1 's st rong points is the shutter. Mo re and more cameras are go ing to the compact Seiko — the Pentax ME and MV , the Nikon EM, a nd the
Mamiya ZE t o name a few. The repair techn iques we 've described f or the XD -11 shut ter also apply to the Seikos used in other cameras.
The Seiko makes the camera excep tionally modula r as wel l as dura ble. Those whi te, plastic gears in the Seiko aren't ny lon — they're Delrin, the toughest of
plastics. The Delrin parts never seem to break. Although the Seiko holds up un der
most type s of abuse, there's one mis treatment it can't take — water damage. Wat er quickly destroys the metal blades.
We've tr ied to cover the trouble sh oo ting and repair tech niques through out this article. The foll owing chart pro vides a summary of t he troubleshooting:
Sympto m
Blades stick
Shu tter will not release, LEDs o.k.
Shutter hangs open on all ele ctronic functions 2. Trigger-swit ch wire blade or black
Cause
1. Oil on blades
1. Release magnet M1, Fig. 60, stick ing (grease betwee n magne t core and armature).
2. Release switch S3, Fig. 101 — poor cont ac t o r out of adjustment.
3. Reset switch S1, Fig. 128 — poor contact. S1 should be closed with the s hutter cocked.
4. Ground screw on lower circuit board loose.
5. Release magnet M 1, capacitor C6, or transist or T6 on lower circuit board. Test b y sho rting the yellow wire on the lower circuit board to ground; the shu tter should release, Fig. 22.
6. IC2. Check the voltage at the yellow wire on the lower circuit board; the voltage shou ld drop from 3V to OV when you close S3, s hu tte r cocked. The LED base plate, Fig. 104, is not
available separately; replace the complete flex.
1. Insulator off lever that opens memory switch, Fig. 33.
wire to shutter module shorted to
Sy mptom
Camera jams with
lens installed (diaphragm fails
to reopen)
Film will not
advance
Over exposure at high ligh t levels and fast manual speeds
No LEDs with release butt on button part ially depressed, shut ter works ok
Cause
ground. Check with an ohmmeter bet ween ground and the black wire,
Fig. 39; you should measure d irect
continuity with the shutter cocked,
no continuity with t he shutter released.
3. Me mory switch, Fig. 33 — poor contact.
1. Mirr or-tensionin g lever, Fig. 108 — sticking .
1. Wind latc h out of adjustment, Fig. 128.
2. Take-u p spoo l, lowe r section, broken loose.
1. Oil on interface of shutter electro magnet and armature.
1. Met ering switch S5, Fig. 101 poor contact or out of a dju stmen t. Check
by shor ting the green wire, Fig. 39,
to ground. If the LEDs then turn on,
pull the mirr or c age and clean the metering sw itch.
2. Switch S7, Fig. 61, poor contact. The pin on the M1 armature should
Symptom
Cause
Sympto m
Causa
Shutter does not release, no LEDs
Un derexposur e in S mode
Diaphra gm
always stops
down fully in S mode, LEDs ok
come a gainst t he blade of S7 with th e mirror cage tensioned.
1. No voltage to the lower circuit board. Chec k for 3V at the red wire, Fig. 21. If you do not get the battery volt age, che ck t he battery compartment and the wiring.
2. H-IC d efective. Check for 3V at pin 1 of IC1, Fig. 65, with the release partially depressed. If you do not get the bat tery voltage, remove the mirror cage, connec t a DC power supply, and check for 3V at pin 6 of H-IC with the release partially depres sed, Fig. 51. If you get OV at pin 6, bu t 3V at pin 5, replace H-IC.
1. Diaphragm-control magnet M2, Fig. 62 — oil on interface between
core and armature.
1. Diaphragm-control magnet M2, C5,
T5, or T13. Test the components as d escrib ed on page 18, Mar-Apr
1980 issue.
Over range LED remains on, dia phragm sto ps · down fully in S mode, sh utt er delive rs only fastes t
mechanical speed
in S an d A modes
Overrange LED remai ns on, other
fun ct ions ok
LED indication does not change in S mode
3. Trigger switch S4, poor contact.
1. Film-speed resistor SV, poor contact.
2. Mode swi tch, poo r contact.
1. Diap hragm resisto r, poor contact. Check for a changing voltage at the A V con tact, Fig. 54, as you rotate the diaphragm-metering ring with the release butto n partiall y depressed.
1. Min imum-a pe rture resistor. Fig. 59, poor contact.
2. Break in flex st rip conne cting diaphragm resistor to the flex circuit. Chec k the MD common vol tage at the point shown in Fig. 54 in the S mode. You should measure 1.1 to
2.2V without a lens.
Diaphragm fai ls to stop down in S mode, other
functions ok
Shutt er delivers
faste st speed
only, othe r
funct ions ok
1. Diaphragm-contr ol magnet M2, Fig. 62, fails to hold its armature. Check for a dirty inter face b etween
the c ore and armatu re, and check
the adjustment. Fig. 68.
1. Electromagnet M3, open coil or not holding its armature. C heck by shorting the brown wire , Fig. 39, to ground as y ou release t he shutter. The shutter should stay open for as long as you hold the short. If not, the prob lem is with t he shut ter electromag net M3.
2. Capacitor C9 (between the brown and red mag net leads, Fig. 39) sho rted.
3. H-IC defective. Check the volta ge at pin 10, Fig. 51. You should get 3V
when the shut ter releases.
4. IC1 defective. C heck the voltage at the brown electroma gnet w ire. Fig.
39. You should get OV when the shut ter releases. If the brown wire
remains at 3V, th e IC1 comparator is n't switching low.
Shutter ha ngs
open on manual-
speed settings,
other functions ok
Ca nnot adjust
fa st manual
speeds
1. Shutter-speed (TV) resistor, poor co ntact.
2. Shutter-speed-resistor board, sh ifted in position.
1. Trigger-switch S4, poor contact o r adjustment.
2. Constant-current adjustment (Rx7 in Fig. 69) incorrect. Check for 180mv betwe en the points in dicated in Fig.
69 — the film- speed resi stor must be
assembled to get the proper voltage reading.
Auto speeds errat ic
1. Air cylinder on side of mirror cage, Fig. 107, dirty , or memory-time-lag
ad justment incorrect.
2. Memory switch, poor contact.
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