7. Electrical Parts List ...................................................................................................................................... 32
X
R582 Confi rmation Method (Hold Down Confi rmation) and Readjustments...........................14
KV-20S90 / 21SE43C
— 2 —
SPECIFICATIONS
KV-21SE43CKV-20S90
Power requirements220V 50Hz120V 60Hz
Number of Inputs/Outputs
Audio Input
Speaker output (W)4W x 23W x 2
Power Consumption (W)
In use (Max)95W90W
In Standby1W1W
Dimensions(W/H/D)
1)
Video
2)
22
22
mm522 x 477 x 479 mm522 x 477 x 479 mm
5
/
in 20
x 18 13/16 x 18 7/8 in. 20 5/8 x 18 13/16 x 18 7/8 in.
Design and specifi cations are subject to change without notice.
— 3 —
KV-20S90 / 21SE43C
WARNINGS AND CAUTIONS
CAUTION
Short circuit the anode of the picture tube and the anode cap to the metal chassis, CRT shield, or carbon painted on the CRT,
after removing the anode.
WARNING!!
An isolation transformer should be used during any service to avoid possible shock hazard, because of live chassis. The chassis of
this receiver is directly connected to the AC power line.
!SAFETY-RELATED COMPONENT WARNING!!
Components identifi ed by shading and ! mark on the schematic diagrams, exploded views, and in the parts list are critical for
safe operation. Replace these components with Sony parts whose part numbers appear as shown in this manual or in supplements
published by Sony. Circuit adjustments that are critical for safe operation are identifi ed in this manual. Follow these procedures
whenever critical components are replaced or improper operation is suspected.
ATTENTION!!
Apres avoir deconnecte le cap de l’anode, court-circuiter l’anode du tube cathodique et celui de l’anode du cap au chassis metallique
de l’appareil, ou la couche de carbone peinte sur le tube cathodique ou au blindage du tube cathodique.
Afi n d’eviter tout risque d’electrocution provenant d’un chássis sous tension, un transformateur d’isolement doit etre utilisé lors de tout
dépannage. Le chássis de ce récepteur est directement raccordé à l’alimentation du secteur.
! ATTENTION AUX COMPOSANTS RELATIFS A LA SECURITE!!
Les composants identifi es par une trame et par une marque ! sur les schemas de principe, les vues explosees et les listes de
pieces sont d’une importance critique pour la securite du fonctionnement. Ne les remplacer que par des composants Sony dont
le numero de piece est indique dans le present manuel ou dans des supplements publies par Sony. Les reglages de circuit dont
l’importance est critique pour la securite du fonctionnement sont identifi es dans le present manuel. Suivre ces procedures lors de
chaque remplacement de composants critiques, ou lorsqu’un mauvais fonctionnement suspecte.
— 4 —
SAFETY CHECK-OUT
KV-20S90 / 21SE43C
After correcting the original service problem, perform the following
safety checks before releasing the set to the customer:
1. Check the area of your repair for unsoldered or poorly soldered
connections. Check the entire board surface for solder splashes and
bridges.
2. Check the interboard wiring to ensure that no wires are “pinched” or
touching high-wattage resistors.
3. Check that all control knobs, shields, covers, ground straps, and
mounting hardware have been replaced. Be absolutely certain that
you have replaced all the insulators.
4. Look for unauthorized replacement parts, particularly transistors,
that were installed during a previous repair. Point them out to the
customer and recommend their replacement.
5. Look for parts which, though functioning, show obvious signs of
deterioration. Point them out to the customer and recommend their
replacement.
6. Check the line cords for cracks and abrasion. Recommend the
replacement of any such line cord to the customer.
7. Check the B+ and HV to see if they are specifi ed values. Make sure
your instruments are accurate; be suspicious of your HV meter if sets
always have low HV.
8. Check the antenna terminals, metal trim, “metallized” knobs, screws,
and all other exposed metal parts for AC leakage. Check leakage
as described below.
Leakage Test
The AC leakage from any exposed metal part to earth ground and from
all exposed metal parts to any exposed metal part having a return to
chassis, must not exceed 0.5 mA (500 microamperes). Leakage current
can be measured by any one of three methods.
1. A commercial leakage tester, such as the Simpson 229 or
RCA WT-540A. Follow the manufacturers’ instructions to use these
instructions.
2. A battery-operated AC milliampmeter. The Data Precision 245 digital
multimeter is suitable for this job.
3. Measuring the voltage drop across a resistor by means of a VOM
or battery-operated AC voltmeter. The “limit” indication is 0.75 V,
so analog meters must have an accurate low voltage scale. The
Simpson’s 250 and Sanwa SH-63TRD are examples of passive VOMs
that are suitable. Nearly all battery-operated digital multimeters that
have a 2 VAC range are suitable (see Figure A).
How to Find a Good Earth Ground
A cold-water pipe is a guaranteed earth ground; the cover-plate retaining
screw on most AC outlet boxes is also at earth ground. If the retaining
screw is to be used as your earth ground, verify that it is at ground
by measuring the resistance between it and a cold-water pipe with an
ohmmeter. The reading should be zero ohms.
If a cold-water pipe is not accessible, connect a 60- to 100-watt troublelight (not a neon lamp) between the hot side of the receptacle and the
retaining screw. Try both slots, if necessary, to locate the hot side on the
line; the lamp should light at normal brilliance if the screw is at ground
potential (see Figure B).
To Exposed Metal
Parts on Set
Trouble Light
Ohmmeter
0.15 F
1.5 K Ω
AC Outlet Box
AC
Voltmeter
(0.75 V)
Earth Ground
Figure A. Using an AC voltmeter to check AC leakage.Figure B. Checking for earth ground.
— 5 —
Cold-water Pipe
KV-20S90 / 21SE43C
SELF-DIAGNOSTIC FUNCTION
Self Diagnosis
Supported model
The units in this manual contain a self-diagnostic function. If an error occurs, the STANDBY/TIMER LED will automatically begin to fl ash. The number
of times the LED fl ashes translates to a probable source of the problem. A defi nition of the STANDBY/TIMER LED fl ash indicators is listed in the
instruction manual for the user’s knowledge and reference. If an error symptom cannot be reproduced, the Remote Commander can be used to review
the failure occurrence data stored in memory to reveal past problems and how often these problems occur.
Diagnostic Test Indicators
When an error occurs, the STANDBY/TIMER LED will fl ash a set number of times to indicate the possible cause of the problem. If there is more than
one error, the LED will identify the fi rst of the problem areas.
Results for all of the following diagnostic items are displayed on screen. No error has occurred if the screen displays a “0”.
Diagnostic Item
Description
Power does not turn on
+B overcurrent (OCP)*
Vertical Defl ection
Stopped
White Balance failure
(not balanced)
No. of times
STANDBY/ TIMER
lamp fl ashes
Does not light
2 times
4 times
5 times
Self-Diagnositc
Display/
Diagnostic Result
2:0 or 2:1
4:0 or 4:1
5:0 or 5:1
Probable Cause Location
• Power cord is not plugged in.
• Fuse is burned out (F601). (A Board)
• H.OUT (Q502) is shorted.(A Board)
• IC1751 (C Board) is shorted.
• +13V is not supplied. (A Board)
• IC541 is faulty. (A Board)
• Video OUT (Q392 to Q394) is faulty.
(A Board)
• IC301 is faulty. (A Board)
• Screen (G2) is improperly
Detected Symptoms
• Power does not come on.
• No power is supplied to the TV.
• AC Power supply is faulty.
• Power does not come on.
• Load on power line is shorted.
• Has entered standby state after horizontal raster.
• Vertical defl ection pulse is stopped.
• Power line is shorted or power supply is stopped.
• No raster is generated.
• CRT Cathode current detection reference pulse
output is small.
*If a +B overcurrent is detected, stoppage of the vertical defl ection is detected simultaneously. The symptom that is diagnosed fi rst by the
mircrocontroller is displayed on the screen.
**Refer to Screen (G2) Adjustments in Section 2-4. of this manual.
Display of Standby/Timer LED Flash Count
2 times
4 times
5 times
LED ON 0.3 sec.
LED OFF 0.3 sec.
LED OFF
3 sec.
Standby/Timer LED
Diagnostic Item Flash Count*
+B Overcurrent 2 times
Vertical Defl ection Stopped 4 times
White Balance Failure 5 times
*One fl ash count is not used for self-diagnostic.
Stopping the Standby/Timer LED Flash
Turn off the power switch on the TV main unit or unplug the power cord from the outlet to stop the STANDBY/TIMER LAMP from fl ashing.
— 6 —
KV-20S90 / 21SE43C
Self-Diagnostic Screen Display
For errors with symptoms such as “power sometimes shuts off” or “screen sometimes goes out” that cannot be confi rmed, it is possible to bring up
past occurrences of failure on the screen for confi rmation.
To Bring Up Screen Test
In standby mode, press buttons on the Remote Commander sequentially, in rapid succession, as shown below:
Display
Self-Diagnostic Screen Display
Handling of Self-Diagnostic Screen Display
Since the diagnostic results displayed on the screen are not automatically cleared, always check the self-diagnostic screen during repairs. When you
have completed the repairs, clear the result display to “0”.
Unless the result display is cleared to “0”, the self-diagnostic function will not be able to detect subsequent faults after completion of the repairs.
Clearing the Result Display
To clear the result display to “0”, press buttons on the Remote Commander sequentially when the diagnostic screen is displayed, as shown below:
Channel
Quitting the Self-Diagnostic Screen
To quit the entire self-diagnostic screen, turn off the power switch on the Remote Commander or the main unit.
Channel
SELF DIAGNOSTIC
2: 000
3: N/A
4: 000
5: 001
101: N/A
8
ENTER
5
Sound Volume - Power ON
Note that this differs from entering the Service Mode (Sound Volume
Numeral “0” means that no fault was detected.
Numeral “1” means a fault was detected one time only.
+
).
Self-Diagnostic Circuit
FROM
CRT
IC301
Y/CHROMA JUNGLE
21
IK IN
IC541
V. OUT
REF
IC001
SYSTEM
IO-BDAT
3
17
I-PROT
36
IC003
MEMORY
5
BDA
FROM
18
IC521
PIN 7
+B overcurrent (OCP)
Occurs when an overcurrent on the +B (115V) line is detected by pin 18 of IC301. If the voltage of pin 18 of IC301 is less than 1V when V.SYNC is more
than seven verticals in a period, the unit will automatically turn off.
Vertical Defl ection Stopped
Occurs when an absence of the vertical defl ection pulse is detected by pin 17 of IC001. Power supply will shut down when waveform interval
exceeds 2 seconds.
White Balance Failure
If the RGB levels* do not balance within 2 seconds after the power is turned on, this error will be detected by IC301. TV will stay on, but there
will be no picture.
*(Refers to the RGB levels of the AKB detection Ref pulse that detects 1K).
HP/PROTECT
SDA
35
37
IO-SDAT
O-LED
18
DISPLAY
— 7 —
1-1. REAR COVER REMOVAL
KV-20S90 / 21SE43C
SECTION 1: DISASSEMBLY
2 Screws +BVTP 4x16
Rear Cover
Screw +BVTP 4x16
1-2. CHASSIS ASSEMBLY REMOVAL1-3. SERVICE POSITION
Screw +BVTP 4x16
Claw
Chassis Assembly
C Board
A Board
— 8 —
1-4. PICTURE TUBE REMOVAL
WARNING: BEFORE REMOVING THE ANODE CAP
High voltage remains in the CRT even after the power is disconnected. To avoid electric shock,
discharge CRT before attempting to remove the anode cap. Short between anode and CRT
coated earth ground strap.
KV-20S90 / 21SE43C
Coated
Earth
Ground
Strap
1
10
5
1. Discharge the anode of the CRT and remove the anode cap.
2. Unplug all interconnecting leads from the defl ection yoke, neck
8
7
assembly, degaussing coils and CRT grounding strap.
3. Remove the C Board from the CRT.
6
3
4. Remove the chassis assembly.
5. Loosen the neck assembly fi xing screw and remove.
2
6. Loosen the defl ection yoke fi xing screw and remove.
7. Place the set with the CRT face down on a cushion and remove
9
the degaussing coil holders.
8. Remove the degaussing coils.
9. Remove the CRT grounding strap and spring tension devices.
10. Unscrew the four CRT fi xing screws [located on each CRT
corner] and remove the CRT [Take care not to handle the CRT
by the neck].
4
ANODE CAP REMOVAL PROCEDURE
WARNING: High voltage remains in the CRT even after the power is disconnected. To avoid electric shock, discharge CRT before attempting to
remove the anode cap. Short between anode and coated earth ground strap of CRT.
NOTE: After removing the anode cap, short circuit the anode of the picture tube and the anode cap to either the metal chassis, CRT shield, or
carbon painted on the CRT.
c
b
a
Anode Button
Turn up one side of the rubber cap in
1
the direction indicated by arrow
a
.
Use your thumb to pull the rubber
2
cap fi rmly in the direction indicated
by arrow
.
b
HOW TO HANDLE AN ANODE CAP
1. Do not use sharp objects which may cause damage to the surface of the anode
cap.
2. To avoid damaging the anode cap, do not squeeze the rubber covering too hard.
A material fi tting called a shatter-hook terminal is built into the rubber.
3. Do not force turn the foot of the rubber cover. This may cause the shatter-hook
terminal to protrude and damage the rubber.
When one side of the rubber cap separates from
3
the anode button, the anode cap can be removed
by turning the rubber cap and pulling it in the
direction of arrow
.
c
— 9 —
SECTION 2: SET-UP ADJUSTMENTS
KV-20S90 / 21SE43C
The following adjustments should be made when a complete
realignment is required or a new picture tube is installed.
These adjustments should be performed with rated power supply
voltage unless otherwise noted.
Set the controls as follows unless otherwise noted:
VIDEO MODE: Standard
PICTURE CONTROL: Normal
BRIGHTNESS CONTROL: Normal
2-1. BEAM LANDING
Before beginning adjustment procedure:
1. Degauss the entire screen.
2. Feed in the white pattern signal.
ADJUSTMENT PROCEDURE
1. Input a raster signal with the pattern generator.
2. Loosen the defl ection yoke mounting screw, and set the purity control
to the center as shown below:
Purity Control
Perform the adjustments in order as follows:
1. Beam Landing
2. Convergence
3. Focus
4. Screen (G2)
5. White Balance
Note Test Equipment Required:
1. Color Bar Pattern Generator
2. Degausser
3. DC Power Supply
4. Digital Multimeter
6. Switch over the raster signal to red and blue and confi rm the
condition.
7. When the position of the defl ection yoke is determined, tighten it with
the defl ection yoke mounting screw.
8. If landing at the corner is not right, adjust by using the disk magnets.
3. Turn the raster signal of the pattern generator to green.
4. Move the defl ection yoke backward, and adjust with the purity control
so that green is in the center and red and blue are even on both
sides.
Blue Red
Green
5. Move the defl ection yoke forward, and adjust so that the entire screen
becomes green.
— 10 —
Diskmagnets
orrotatabledisk
magnetscorrect
theseareas(a-d)
b
d
Puritycontrol
correctsthisarea
ba
cd
Deflectionyokepositioning
correctstheseareas
a
c
KV-20S90 / 21SE43C
2-2. CONVERGENGE
Before starting convergence adjustments:
1 Perform FOCUS, VLIN and VSIZE adjustments.
2. Set BRIGHTNESS control to minimum.
3. Feed in dot pattern.
VERTICAL STATIC CONVERGENCE
1. Adjust V. STAT magnet to converge red, green and blue dots in the
center of the screen (Vertical movement adjust V.STAT RV701 to
converge).
Center dot
R G B
R
G
B
V.STAT magnet
If the blue dot does not converge with the red and green dots, peform
the following:
1. Turn the POWER switch ON. Input a white signal and set the
PICTURE and BRIGHTNESS controls to maximum.
2. Confi rm that the voltage between C574 (+) and ground is more than
99.8 VDC when set is operating normally with 120 +/- 2 VAC.
HOLD-DOWN OPERATION CONFIRMATION
1. Connect the current meter between Pin 11 of the FBT (T504) and
the PWB land where Pin 11 would normally attach (See Figure 1 on
the next page).
2. Input a dot signal and set PICTURE and BRIGHTNESS to minimum:
IABL = 95 + 100/-95µA.
3. Confi rm the voltage of A Board TP-600 is 117 ± 0.3 VDC.
4. Connect the digital voltmeter and the DC power supply via Diode
1SS119 to C574 (+) and ground (See Figure 1 on next page).
5. Increase the DC power voltage gradually until the picture blanks out.
6. Turn DC power source off immediately.
7. Read the digital voltmeter indication (standard: less than or equal to
127.3 VDC).
8. Input a white signal and set PICTURE and BRIGHTNESS to
maximum: (standard: less than or equal to 127.3 VDC).
9. Repeat steps 4 to 7.
HOLD-DOWN READJUSTMENT
If the setting indicated in Step 2 of Hold-Down Operation Confi rmation
cannot be met, readjustment should be performed by altering the
resistance value of R582 component marked with
X
.
T504
FBT
ampmeter
3.0 mA DC
range
ABL
+
-
A
IABL
3-2. B+ VOLTAGE CONFIRMATION AND
ADJUSTMENT
Note: The following adjustments should always be performed when
replacing the following components, which are marked with
schematic diagram on the A Board:
52FSCG Output On/Off0,101
53K-IDB Output On/Off0,100
54HOSCHorizontal VCO Oscillation Freq.0-15107
55VSSVertical Sync Slice Level0,100
56HSSHorizontal Sync Slice Level0,100
57HMSKHMASK On/Off0,111
58VTMSSelect Signal VTIM Pin0-300
59CDMDVertical Count Down Mode Switching0-333**
60AFCAFC Loop Gain Switching0-300*
61FIFRField Frequency0-333
62SBASSub Bass0-1588
63STRESub Treble0-1599
64SBALSub Balance0-151313
65DISPO.S.D Display Position0-127155
66PADJPOWER ADJUSTMENT0-635142
67HCHMH SYNCH SEP. LIMIT FOR TUNER0-1276969
68HCLMH SYNCH SEP. LIMIT FOR TUNER0-1271616
69HCHSH SYNCH SEP. LIMIT FOR VIDEO0-1276969
70HCLSH SYNCH SEP. LIMIT FOR VIDEO0-1271616
71ID00-255SEE ID MAP
72ID10-255SEE ID MAP
73ID20-255SEE ID MAP
74ID30-255SEE ID MAP
75ID4 0-255SEE ID MAP
76ID50-255SEE ID MAP
77ID60-255SEE ID MAP
78ID70-255SEE ID MAP
RANGE
INITIAL
DATAVIDEO
AVERAGE
DATA
* = TV/VIDEO = 0
** = TV = 0, VIDEO = 1
Notes:
Mode
No. 1-78 show the order that each adjustment mode may be selected while in Service Mode.
Data Range shows the range of possible setting for each Adjustment Mode.
Initial Data shows the standard settings for each Adjustment Mode.
Function
SERVICE
ID025
Data
ID MAP
ModelDestinationID-0ID-1ID-2ID-3ID-4ID-5ID-6ID-7
KV-20S90US25312273100
KV-21SE43CE1731195115100
4-4. A BOARD ADJUSTMENTS
H. FREQUENCY ADJUSTMENT
1. InputTV mode (RF) with no signal.
2. Set to Service Adjustment Mode.
3. Connect a frequency counter to base of Q501
(TP-500 H. DRIVE).
4. Check H. Frequency for 15735 ± 200 Hz.
5. Press
MUTING
then
ENTER
to save into the memory.
— 18 —
V. FREQUENCY CHECK
1. Select video 1 with no signal input.
2. Set the conditions for a standard setting.
3. Connect the frequency counter to TP-508 or CN501 pin
connector and ground.
4. Check that V. Frequency shows 60 ± 4 Hz.
6
SUB CONTRAST ADJUSTMENT (RDRV)
(V DY+)
KV-20S90 / 21SE43C
DISPLAY POSITION ADJUSTMENT (DISP)
1. Input a color-bar signal.
2. Set to Service Adjustment Mode.
3. Select DISP with
4. Adjust values of DISP with
5. Write to memory by pressing
6. Check to see if the text is displayed on the screen.
1
and 4 .
3
and 6 to adjust characters to the center.
MUTING
then
ENTER
.
1. Input a color-bar signal.
2. Set the red color on (1).
3. Set in Service Adjustment Mode.
4. Select the item DCOL level to 0.
5. Set the conditions as follows:
PICTURE: MAX
COLOR: MIN
BRIGHT: CENTER
R ON: ON (1)
G ON: OFF (0)
B ON: OFF (0)
Mode
SERVICE
6. Connect an oscilloscope probe to CN301 pin
ground .
1
7. Select RDRV with
8. Adjust the value of RDRV with
1.50 ± 0.05 Vpp.
and 4 .
Display
Item
RON
3
and 6 for
White
1.50 ± 0.05 Vpp
1: ON
0: OFF
26
2
(Red Out) and
Mode
SERVICEDISP15
Display
Item
Item
Data
SUB BRIGHT ADJUSTMENT (SBRT)
1. Input a crosshatch signal.
2. Set to Service Adjustment Mode.
3. Set the PICTURE and BRIGHTNESS to minimum.
4. Select the SBRT item with
5. Adjust the values of SBRT with
crosshatch.
6. Press
MUTING
then
1
and 4 .
ENTER
3
and 6 to obtain a faintly visible
to save into the memory.
SUB HUE, SUB COLOR ADJUSTMENT (SHUE,
SCOL)
1. Input a color-bar signal.
2. Set to Service Adjustment Mode.
3. Connect a probe to TP47B B-OUT (C Board).
4. Measure white V1 and blue V4.
4.1) Increase SCOL Register +1 setp.
Black
9. Reset the item DCOL to 1.
10. Press
11. Return the following back to normal after adjustment.
Perform this adjustment after performing H. Frequency.
1. Input a crosshatch signal.
2. Set to Service Adjustment Mode.
3. Select the HPOS item with
4. Adjust the value of HPOS with
5. Press
MUTING
then
1
and 4 .
3
and 6 for the best horizontal center.
ENTER
to save into the memory.
V. LINEARITY (VLIN), V. CORRECTION
1. Input a crosshatch signal.
2. V.Correction is automatically adjusted from the circuit and should
satisfy the conditions below.
V LINEARITY (VLIN)
V CORRECTION
— 20 —
5-1. CIRCUIT BOARDS LOCATION
SECTION 5: DIAGRAMS
Circled numbers are waveform references.
The components identifi ed by
been carefully factory-selected for each set in order to satisfy regulations
regarding X-ray radiation. Should replacement be necessary, replace
only with the value originally used.
KV-20S90 / 21SE43C
X
in this basic schematic diagram have
C Board
A Board
5-2. PRINTED WIRING BOARD AND
SCHEMATIC DIAGRAM INFORMATION
All capacitors are in µF unless otherwise noted. pF : µµF 50WV or less
are not indicated except for electrolytics and tantalums.
All electrolytics are in 50V unless otherwise specifi ed.
All resistors are in ohms. K=1000, M=1000k
Indication of resistance, which does not have one for rating electrical
power, is as follows:
Pitch : 5mm
Rating electrical power :
1
/
W in resistance, 1/
4
: nonfl ammable resistor.
: fusible resistor.
: internal component.
: panel designation and adjustment for repair.
All variable and adjustable resistors have characteristic curve B, unless
otherwise noted.
Readings are taken with a color-bar signal input.
Readings are taken with a 10M digital multimeter.
Voltages are DC with respect to ground unless otherwise noted.
Voltage variations may be noted due to normal production tolerances.
All voltages are in V.
S : Measurement impossibillity.
: B+line.
:B-line. (Actual measured value may be different).
: signal path. (RF)
1
W and 1/
10
/
W
4
W in chip resistance.
8
When replacing components identifi ed by
Y
, make the necessary
adjustments as indicated. If the results do not meet the specifi ed value,
change the component identifi ed by
X
and repeat the adjustment until
the specifi ed value is achieved. (Refer to Safety Related Adjustments
on Page 14.)
When replacing the parts listed in the table below, it is important to
perform the related adjustments.