JVC MXK-350-V Service manual
SERVICE MANUAL
COMP ACT COMPONENT SYSTEM
MX-K350V
MX-K350V
Contents
Safety precautions ----------------------------- 1- 2
Important f or la ser products ------------------ 1- 3
Preventing static electricity------------------- 1- 4
Disa ssembly method -------------------------- 1- 5
Adjustment method --------------------------- 1-18
COPYRIGHT © 2001VICTOR COMPANY OF JAPAN, LTD.
Area Suffix
..................
US
..................
UX
Flow of functional
operation until TOC read --------------- 1-20
Maintena nce of la ser pickup ---------------- 1-21
Repla cement of la ser pickup---------------- 1-21
Description of ma jor ICs --------------------- 1-22
SINGAPORE
SAUDI
No.21166
Dec.2002
Safety Precautions
1. This design of this product contains special hardware and many circuits and components specially or
safety purposes. For continued protection, no changes should be made to the original design unless
authorized in writing by the manufa cturer . Replace ment parts must be identical to those used in the original
circuits. Services should be performed by qualified personnel only .
2. Alterations of the design or circuitry of the product should not be made. Any design alterations of the
product should not be made. Any design alterations or addition s will void the manufa cturer`s warranty a nd
will further relieve the manufa cture of responsibility for personal in jury or property damage resulting therefrom.
3. Many electrical and mechanical parts in the products have special safety-related characteristics. These
characteristics are often not evident from visual inspection nor can the protection afforded by them
necessarily be obtained by using replacement components rated for higher voltage, wattage, etc.
Replac ement parts which have these special safety chara cteristics are identified in the Parts List of Service
Manual. Electrical components having such fe atures are identified by shading on the schematics a nd by
( ! ) on the Parts List in the Service Ma nual. The use of a substitute repla cement which does not have the
same safety characteristics as the recommended replacement parts shown in the Parts List of Service
Manual may create shock, f ire, or other hazards.
4. The leads in the products are routed and dressed with ties, clamps, tubings, barriers and the like to be
separated from live parts, high temperature parts, moving parts and/or sharp edge s for the prevention
of electric shock and f ire hazard. When service is required, the origin al lead routing a nd dre ss should
be observed, and it should be confirmed that they have been returned to normal, after re-a sse mbling.
5. Leakage currnet che ck (Electrical shock hazard testing)
After re-assembling the product, always perform an isolation check on the exposed metal parts of the
product (antenna termin als, knobs, metal cabinet, screw heads, hea dphone ja ck, control shafts, etc.) to
be sure the product is safe to operate without danger of electrical shock. Do not use a line isolation
trans former during this check.
l Plug the AC line cord directly into the AC outlet. Using a “ Leakage Current Tester ”, measure the
leak age current from ea ch exposed metal parts of the ca binet, particularly a ny exposed metal part
having a return path to the chassis, to a known good earth ground. Any leakage current must not
exceed 0.5mA AC (r.m.s.)
l Alternate check method
Plug the AC line cord dire ctly into the AC outlet. Use a n AC voltmeter having, 1,000 ohms per volt
or more sensitivity in the following ma nner. Connect
a 1,500
10W resistor paralleled by a 0.15
AC-type capacitor between an exposed metal
part and a known good earth ground. Mea sure the
AC voltage across the resistor with the AC
voltmeter.
Move the resistor connection to ea ch exposed metal
part, particularly any exposed metal part having a
return path to the chassis, and meausre the AC
voltage across the resistor . Now, reverse the plug in
the AC outlet a nd repeat ea ch measurement. V oltage
mea sured Any must not exceed 0.75 V AC (r.m.s.).
This corresponds to 0.5 mA AC (r.m.s.).
F
Warning
1. This equipment ha s been designed and ma nufactured to meet international safety sta ndards.
2. It is the legal responsibility of the repairer to ensure that these safety standards are maintained.
3. Repairs must be made in accorda nce with the relevant safety sta ndards.
4. It is essential that safety critical components are repla ced by approved parts.
5. If mains voltage selector is provided, check setting for local voltage.
In regard with component parts appearing on the silk-screen printed side (parts side) of the PWB diagrams, the
parts that are printed over with black such as the resistor ( ), diode ( ) and ICP ( ) or identified by the
!
“
”mark nearby are critical for safety.
When replacing them, be sure to use the parts of the same type and rating as specified by the manufacturer.
(Except the J and C version)
! CAUTION
Burrs formed during molding may
be left over on some parts of the
chassis. Therefore, pay attention
to such burrs in the case of
preforming repair of this system.
1-2
Important for laser products
1. CLASS 1 LASER PRODUCT
2. DANGER : Invisible laser radiation when open and inter
lock failed or defeated. Avoid direct exposure to beam.
3. CAUTION : There are no serviceable parts inside the La ser
Unit. Do not disassemble the Laser Unit. Replace the
complete Laser Unit if it malfunctions.
4. CAUTION : The compact disc player uses invisible laser
radiation and is equipped with safety switches which
prevent emission of radiation when the drawer is open
and the safety interlocks have failed or are defeated. It is
dangerous to defeat the safety switches.
VARNING : Osynlig laserstrålning är denna del är
öppnad och spårren är urkopplad. Betrakta
ej strålen.
VARO : Avattaessa ja suojalukitus ohitetta essa olet
alttiina näkymättömälle lasersäteilylle. Älä
katso säteeseen.
5. CAUTION : If safety switches malfunction, the la ser is able
to function.
6. CAUTION : Use of controls, adjustments or performa nce of
procedures other than those specified herein may result
in hazardous radiation exposure.
! CAUTION Please use enough caution not to
see the bea m directly or touch it in
case of a n adjustment or operation
check.
ADVARSEL : Usynlig laserstråling ved åbning, når
sikkerhedsafbrydere er ude af funktion.
Undgå udsættelse for stråling.
ADVARSEL : Usynlig laserstråling ved åpning, når
sikkerhetsbryteren er avslott. Unngå
utsettelse for stråling.
REPRODUCTION AND POSITION OF LABELS
W ARNING LABEL
1-3
Preventing static electricity
1. Grounding to prevent da mage by static electricity
Electrostatic discharge (ESD), which occurs when static electricity stored in the body, fabric, etc. is
discharged, can destroy the laser diode in the traverse unit (optical pickup). T ake care to prevent this
when performing repairs.
2. About the e arth processing for the de struction prevention by static electricity
In the equipment which uses optical pick-up (laser diode), optical pick-up is destroyed by the static
electricity of the work environment.
Be careful to use proper grounding in the area where repairs are being performed.
2-1 Ground the workbench
Ground the workbench by laying conductive material (such as a conductive sheet) or an iron plate
over it before placing the traverse unit (optical pickup) on it.
2-2 Ground yourself
Use an anti-static wrist strap to release any static electricity built up in your body.
3. Handling the optical pickup
1. In order to maintain quality during transport and before installation, both sides of the laser diode on the
replace ment optical pickup are shorted. After re pla cement, return the shorted parts to their original condition.
(Refer to the text.)
2. Do not use a te ster to check the condition of the la ser diode in the optical pickup. The testers internal power
source can easily destroy the laser diode.
4. Handling the CD cha nger unit (optical pickup)
1. Do not subject the CD changer unit (optical pickup) to strong shocks, as it is a sensitive, complex unit.
2. Cut off the shorted part of the flexible cable using nippers, etc. after replacing the optical pickup. For specific
details, refer to the replacement procedure in the text.
Remove the anti-static pin when replacing the CD changer
unit. Be careful not to take too long a time when atta ching it
to the connector.
3. Handle the flexible cable carefully as it may break when
subjected to strong force.
4. It is not possible to adjust the semi-fixed resistor that adjusts the la ser power. Do not turn it.
Attention when traverse unit is decomposed
* Please refer to “Disassembly method ” in the text for pick
up and how to detach the CD changer mechanism.
1. Remove the CD cha nger unit.
2. Disconnect the harness from connector on the CD motor board.
3. Solder is put up before the card wire is removed from connector
Cn601on the main board as shown in Fig.1 a nd Fig. 2.
(When the wire is removed without putting up solder, the CD
pick-up asse mbly might destroy .)
4. Please remove solder after connecting the card wire with CN601
when you install picking up in the substrate.
1-4
Disa ssembly method
Commence disassembly of this set by re moving the main units and then proceed to the components a nd a ssemblies
inside the units.
Replacement of the fuses a nd the power IC
n Top cover
n CD changer unit
n Front panel a ssembly
n Cha ssis unit
n CD changer unit
n Removing the main PCB
n Removing the CD cha nger me chanism assembly
n Removing the CD pickup
n Repla cing the loa ding motor and belt of the CD changer tray
n Repla cing the CD tray rotor belt of CD changer, and re moving the motor
n Front panel a ssembly
n Removing the cassette deck mechanism
n Removing the earphone jack PCB
n Removing the control/FL PCB
n Removing the switch PCB and ACTIVE BASS EX. switch PCB
n Removing the cassette deck main motor, and re placing the main belts
n Removing the le af switche s of the cassette deck mechanism
n Removing the cassette deck heads
n Chassis unit
n Removing the 3-pin regulator
n Removing the power amp and supply PCB and the Power Trans PCB
n Removing the sub power PCB
1-5
<Disasse mbly of the main blocks of this set>
Repla ce ment of the fuse s and the power IC
n Re pla cing the fuse s (See Fig.1, Fig.3)
n Prior to performing the following procedure, remove
the left side BOARD and remove tuner PCB (Fig.3,BB)
1. Replace the fuse s inside.
[Caution] Be sure to use fuses with the specified ratings.
n Re placing the power IC (See Fig.2 )
n Prior to performing the following procedure, remove
the top cover.
1. Remove the two screws “A ” from the heat sinkbetween
the power IC.
2. Remove the solder fixing the power IC.
n Replacing the heat sink cover
1. Remove the six screws from the back pa nel.
2. Pull the heat sink cover outward.
1-6
n Removing the top cover and two sides
BOARD (See Fig.4 and 5)
1. Remove the six screws “B ” that retain the top cover
from the rear of the body .
2. Remove the eight screws “ C ” and “D ” that retain the
top from the two sides of the body .
3. Remove the top cover from the body by lifting it toward
the rear .
1-7
n Removing the CD changer unit
(See Fig.6 and 9)
n
Prior to performing the following procedures, remove
the top cover and both sides BOARD.
[Caution] Although the CD mechanism unit can be
removed without removing the CD tray
panel, it is still recommended to remove it
in order to prevent da mage.
a. From the front pa nel side of this set, push in the sections
marked with arrows and pull out the CD tray toward
the front.
b. Remove the CD tray panel by pushing both of its
extremities upward in the direction of the arrows.
c. Push the CD tray deep into the set.
1. Disconnect the card wires from the CD PCB CN704,
CN607, CN1 101 and disconnect CN1 (shield wire) from
back pa nel.
2. From the rear of the set, remove the two screws “ E ”
and two serews “G ” on the front panel left and right
side.
3. Handle the CD changer unit re ar , take out unit.
1-8
Fig.6
n Removing the front pa nel a sse mbly
(See Fig.10 and 11)
n
Prior to performing the following procedures, remove
the top cover and both sides board.
n
Also remove the CD changer unit.
1. Disconnect the parallel wire and card wire from the
connectors CN702, CN701, CN703, CN850 on the
power amp a nd supply PCB.
2. Remove the two screws “ H ” retaining the front panel
asse mbly onto the bottom of the body.
3. Remove the screw “ I ” retaining the cassette deck
mechanism a nd then remove then GND lug “ b ” that
comes from the power a mp and supply PCB.
4. Disengage the claws “c ” on both sides at the bottom
of the front panel assembly and then remove the
assembly.
1-9
<Disassembly of units and assembly inside
this set>
n Removing the CD PCB
(See Fig.12 and 13)
n
Prior to performing the following procedures, remove
the top cover and both sides board.
n
Also remove the CD changer unit.
1. The two screws “E ” that retain the VCD assembly
should be removed.
2. Disconnect the wires from CN602, CN603, CN604
and CN605 on the CD PCB, which is located on the
back side of the CD cha nger unit.
3. The two screws “ J ” that retain the CD PCB should be
removed.
4. Remove the CD PCB by pulling it toward the side where
the CN601 is located.
5. Using solder, short the CD pickup to connect to short
round.
[Caution] After re-connecting the wires, be sure to
remove the shorting solder from the GND connection.
6. Disconnect the card wire from the connector CN601
on the main PCB and then remove the main PCB.
1-10
n Removing the CD changer mechanism
assembly (See Fig.14 and 16)
n
Prior to performing the following procedures, remove
the top cover and both sides board.
n
Also remove the CD changer unit.
1. Remove the screws “ d ” from the front chuch base of
the CD changer mechanism unit.
2. Turn the CD changer mecha nism cover base a nd remove
the screws “ e ” connecting the unit to the CD cha nger
mechanism a ssembly .
3. Removing the four screws “ k ” retaining the CD
mechanism holder a ssembly .
[Caution] When replacing the CD changer mecha nism
assembly, be sure not to mistake the
positions of the silver color and copper color
spring.
1-11
n Removing the CD PCB (See Fig.17)
n
Prior to performing the following procedures, remove
the top cover and both sides board.
n
Also remove the CD changer unit.
n
Also remove the CD cha nger mecha nism.
1. Widen the section “ f ” .
2. While keeping the section “ f ” wide open, push the
section “g ” in the direction of the arrow to remove the
shaft, and then remove the CD pickup.
n Repla cing the loading motor and rotor belt
of the CD changer (See Fig.18)
n
Prior to performing the following procedure, remove
the top cover.
n
Also open the CD changer tray.
1. Remove the two screws “L ” retaining the CD cha nger
tray loading motor .
2. Remove the two screws “M ” retaining the gear plate
and take it out, after remove the rotor belt from the
pulley.
n Re placing the CD turn table a nd removing
the motor (See Fig. 19 and 20)
n
Prior to performing the following procedures, remove
the top cover.
n
Also remove the CD changer unit.
1. Remove the one screws “ N ” retaining the CD (Turn
table).
2. Remove the two screws “ O ” retaining the stopper
brackets on both sides of the CD cha nger unit.
3. Remove the stopper brackets from both sides of the
CD cha nger unit.
4. Pull out the CD tray from the CD changer unit, all the
way and lift the tray (u/~ ward) to remove.
5. Remove the gear and after push out the tray motor
locker and pull out the tray motor from the CD tray.
1-12
n Removing the cassette deck mechanism
(See Fig.21)
n
Prior to performing the following procedure, remove
the top cover and both sides board.
n
Also re move the CD cha nger unit.
n
Also re move the front pa nel assembly.
1. Remove the five screws “Z ” retaining the cassette
deck mecha nism.
n Removing the e arphone jack PCB And Mic
Jack PCB (See Fig.22)
n
Prior to performing the following procedure, remove
the top cover and both sides board.
n
Also remove the CD changer unit.
n
Also remove the front panel a sse mbly .
1. Remove the screw with the washer, “ P ” that retains
the earphone jack PCB.
n Removing the control/FL PCB
(See Fig.23)
n
Prior to performing the following procedure, remove
the top cover and both sides board. Also re move the
CD cha nger unit.
n
Also remove the CD cha nger unit.
n
Also remove the front panel a sse mbly .
1. Remove the four screws “ Q ” that retain the control/FL
PCB from the back of the front pa nel unit.
1-13
n Removing the switch PCB and sound
mode and CD function switch PCB
(See Fig.23 to 26)
n
Prior to performing the following procedures, remove
the top cover and both sides board.
n
Also remove the CD changer unit.
n
Also remove the front panel a sse mbly .
1. Pull out the volume control knob and MIC Volume
Knob from the front of the front panel a ssembly .
2. Remove the four screws “Q ” retaining the front panel
assembly.
3. Remove the control / FL PCB.
4. Remove the eleven screws “ R ” retaining the switch
(key 1) PCB.
5. Remove the three screws “ S ” retaining the sound
mode (key 2) switch PCB.
6. Remove two screws “ T ” retaining the CD function
(key 3) switch PCB.
1-14
n Removing the ca ssette deck main motor ,
and re placing the main belts
(See Fig. 21, 27 and 28)
n
Prior to performing the following procedures, remove
the top cover and both sides board.
n
Also re move the CD changer unit.
n
Also remove the front panel assembly.
1. Remove the five screws “z ” retaining the cassette
deck mecha nism.
2. Remove the ca ssette deck mecha nism.
3. Remove the two screws “ t ” retaining the main motor
from the front side of the ca ssette deck.
[Caution] After atta ching the main motor , check the
orientation of the motor and the polarity of
the wires.
4. From the backside of the cassette deck, remove the
main motor and two main belts.
[Caution] The lengths of the cassette A (playback
only) and cassette B (record/play) main
belts are different. When atta ching the main
belts, use the longer belt for ca ssette A.
n Removing the leaf switches of the cas-
sette deck mechanism
(See Fig. 21 and 29)
n
Prior to performing the following procedures, remove
the top cover and both sides board.
n
Also remove the CD changer unit.
n
Also remove the front panel a sse mbly .
1. Remove the five screws “O ” that retain the cassette
deck mecha nism.
2. Remove the ca ssette deck mecha nism.
3. Turn the cassette deck mechanism upside down.
4. Remove the solder from around the leaf switches.
5. Pull out the leaf switches from the front side of the
cassette deck mechanism.
1-15
n Removing the cassette deck heads
(See Fig.21 to 30)
n Removing the 3-pin regulator
(See Q904, Q907, 31)
n
Prior to performing the following procedures, remove
the top cover and both sides board.
n
Also re move the CD cha nger unit.
n
Also re move the front pa nel a sse mbly .
1. Remove the five screws “O ” that retain the cassette
deck mecha nism.
2. Remove the ca ssette deck mechanism a nd place it so
that the front side faces up.
3. Remove the solder from the bottom side of the head
terminal and disconnect the wire.
4. Remove the screw “ U ” that retains the head.
5. Remove the screw “ V ” that retains the head.
6. Hold the head and slide it in the dire ction of the arrow
to remove it.
n
Prior to performing the following procedures, remove
the top cover and both sides board.
1. Remove the two screws “ A ” that connect the heat
sink cover to the rear panel.
2. Pull the heat sink outward.
3. Remove the screw “W ” that retains the heat sink the
3-pin terminal regulator Q904,Q907.
4. Remove the solder fixing the 3-pin regulator .
Fig.31
1-16
n R emoving the power amp a nd supply PCB
and the power trans PCB
(See Fig. 2, 32 to 34)
n
Prior to performing the following procedures, remove
the top cover and both sides board.
n
Also remove heat sink cover .(Fig.3)
1. Remove the two screws “ A ” connecting the heat sink
cover to the rear panel.(Fig.2)
2. Pull out the heat sink cover toward you.
3. Remove four(CA-MXK350V) screws “AA” form the
MX-K350V ba ck panel between the heat sink.
4. Remove the three screws “ X ” that retain the speaker
terminals and aux termin al.
5. Remove the screw “ YY ” and “Y ” that retains the rear
panel, a nd AC switch screw then re move the rear panel.
6. Disconnect the parallel wires from the connectors
FW951 on the power trans PCB.
7. Remove the screw “ Z ” that retain the power amp a nd
supply PCB and then remove the a ssembly .
8. Remove the clamp of AC power cord from the cha ssis.
9. Remove the four screws “ AB ” that retain the power
trans PCB a nd then remove the a ssembly .
1-17
Adjustment method
Mea sure ment in struments required
for adjustment
1. Low frequency oscillator
This oscillator should have a capacity to output 0dB
to 600ohm at an oscillation frequency of 50Hz20kHz.
2. Attenuator impedance : 600ohm
3. Electronic voltmeter
4. Frequency counter
5. Wow flutter meter
6. Test tape
VT712 : For Tape speed and wow flutter ( 3kHz)
VT703 : For Head angle(10kHz),Play ba ck frequency
characteristics(1kHz), and dubbing frequency characteristics (63,1,10kHz)
7. Blank tape
TAPE I : AC-225
8. Torque gauge : For play and back tension forward ;
TW2111A, Reverse ; TW2121A Fast Forward and
Rewind ; TW2231A
9. Test disc: CTS-1000(12cm),GRG-1211(8cm),
CD-T05A
10. Jitter meter
11. Television
Mea surement condition s
(Select correct AC Line Volt.)
Power supply voltage
AC110/127/220/230-240V (50/60Hz) US/UX
Measurement
output terminal : Speaker out
: TP101(Measuring for TUNER
DECK/CD/VCD)
: Dummy load 6ohm
Adio input signal
AM modulation frequency : 400Hz
Modulation factor : 30%
FM modulation frequency : 400Hz
Frequency displacement : 22.5kHz
Frequency Range
AM US: 531kHz~1629kHz (9kHz)
530kHz~1710kHz (10kHz)
UX: 531kHz~1602kHz (9kHz)
530kHz~1600kHz (10kHz)
FM 87.5MHz~108MHz
Standard me asurement positions of
volume and switch
Power: Standby (Light STANDBY Indicator)
S, A, BASS : OFF
Sound mode : OFF
Main VOL. : 0 Minimum
Travers mecha set position : Disc 1
Mic MIX VOL : MAX
ECHO : OFF
Precautions for measurement
1. Apply 30pF and 33kohm to the IF sweeper output side
and 0.082 F and 100kohm in series to the sweeper
input side.
2. The IF sweeper output level should be made as low as
possible within the adjustable range.
3. Since the IF sweeper is a fixed device, there is no
need to adjust this sweeper.
4. Since a ceramic oscillator is used, there is no need to
perform any MPX adjustment.
5. Since a fixed coil is used, there is no need to adjust
the FM tracking.
6. The input and output earth systems are separated. In
case of simultaneously measuring the voltage in both
of the input and output systems with an electronic
voltmeter for two channels, therefore, the earth should
be connected particularly.
7. In the case of BTL connection amplifier, the minus
terminal of speaker is not for earthing. Therefore, be
sure not to connect any other earth terminal to this
terminal. This system is of an OTL system.
1-18
n Arrange ment of adjusting position s
n Tape recorder section
Items
Cassette Head
A zimuth Al ignments
Recording Bias
Frequency Alignment
n Tuner section
Items
AM Tracking
Alignments
Measurement
conditions
Input signal:
530kHz (529kH z)
600kHz (603kH z)
Adjustment
point: Antenna
coil (L2)
Measurement
conditions
Test tape :
VT703 (10kHz)
Measurement
output termi nal :
Left and Right
speaker output
(6-ohm loaded)
or Headphone
Output
(32-ohm loaded)
Test tape :
TYPE I AC -225
Measurement
output termi nal :
Erase head
terminal
(CN308 8-Pin)
Measurement method
1. Playback the test tape VT703 (10KHz) or equivalent.
2. Adjust the head azimuth screw to obtain maximum
output and both output of L / R is in 3dB.
3. Put on the screw lock paint after alignments.
1. Insert the recording tape in deck-B.
2. Starting the recording.
3. Adjust the oscillation frequency to 80KHz+/-3KHz
by core of Oscillation coil of L301.
Measurement method
1. Set t he Signal G enerat or sign al to 530KHz (529KHz)
the feed to Loop Antenna.
2. Receiving t he signal and the adju st t he OSC coil (L2)
obtain the V.T is 1.40V +/-0.05V.
3. Ch ange the receiving frequ ency to 600KH z (603KHz).
4. Adjust the Antenna coil ( L2 ) obtain maxi mum
sensitivity .(Ad just the SS G output to out o f AGC
range.)
Standard
values
Maximum output Adjust the
80kHz+/-3kHz Use the High-
Standard
values
V.T :
1.40V+/-0.05V
Adjusting
positions
head azimuth
screw only
when the head
has been
changed.
Impedance
Probe or
Frequency
counter input.
Adjusting
positions
Adjust the OSC
coil only when
the AM c oi l
block has been
changed.
Maximum
sensitivity
AM IFT
Alignments
Input signal:
530kHz (529kH z)
Adjustment
point: IFT (T1)
1. Set the receiving frequency to 530KHz (529KHz ).
2. Feed the 450KHz signal to AM antenna input.
3. Adjust the IFT Block T1 obtain to maxi mum
output.(A djust the SSG output to out of AG C
range.)
Note: The adjustment of CD section is not required.
Maximum output Adjust the IFT
only when the
IFT block h as
been changed.
1-19
Flow of functional operation until T OC read
1-20
Maintenance of laser pickup
(1) Cleaning the pick up len s
Before you replace the pick up, please
try to clean the lens with a alcohol
soaked cotton swab.
(2) Life of the laser diode
When the life of the laser diode has
expired, the following symptoms will
appear .
1. The level of RF output (EFM output: ampli
tude of eye pattern) will below.
Repla c e ment of la ser pickup
(3) Semi-fixed resistor on the APC PC board
The semi-fixed resistor on the APC printed circuit board which is attached to the pickup is used to a djust the laser
power. Since this a djustment should be performed to match the chara cteristics of the whole optical block, do not
touch the semi-fixed resistor .
If the laser power is lower tha n the specified value, the la ser diode is almost worn out, a nd the laser pickup should
be replaced.
If the semi-fixed resistor would be adjusted when the pickup operates normally , the la ser pickup may be da maged
due to excessive current.
1-21
Description of major ICs
n VIDEO CD PROCESSOR CHIP PINOUT
n VIDEO PC PROCESSOR CHIP PIN DESCRIPTION
1-22
n VIDEO CD COMPANION CHIP
1. Pinout
1-23
2. Pin description
1-24
Loading...