Technical Service Data
Volume 420, June 2003
Sets 4733, 4734, 4735, 4736, 4737, 4738, 4739,
4740, 4741, 4742, 4743, 4744 & Photofact Gold 24
This technical service data is available for you to consult but NOT TO PHOTOCOPY .
PHOTOCOPYING THIS MATERIAL IN PAPER OR DIGITAL FORM IS A
VIOLATION OF THE LAW. If you would like your own a paper or electronic copy of a
specific manual, you can order it from Sams Technical Publishing at
www.samswebsite.com or 1.800.428.SAMS. We appreciate your cooperation.
Reproduction or use of editorial or pictorial content, in any manner, electronically or
otherwise, without express permission is prohibited. No responsibility is assumed with
respect to application or patent liability of the included material.
Sams Technical Publishing LLC
9850 E. 30thSt.
Indianapolis IN 46229 U.S.A
www.samswebsite.com
© 2003, Sams Technical Publishing. All rights reserved.
ISBN 0-7906-5420-2
SAFETY PRECASAFETY PRECA
SAFETY PRECA
SAFETY PRECASAFETY PRECA
SERSER
VICE VICE
SER
SERSER
Only qualified service technicians who are familiar with safety checks
and guidelines should perform service work. Before replacing parts,
disconnect power source to protect electrostatically sensitive parts. Do
not attempt to modify any circuit unless so recommended by the
manufacturer. When servicing the receiver, use an isolation transformer
between the line cord and power receptacle.
SERSER
SER
SERSER
Use EXTREME CAUTION when servicing the high voltage circuits. To
discharge static high voltage, connect a 10K ohms resistor in series with a
test lead between the receiver ground and CRT anode lead. DO NOT lift
the CRT by the neck. Always wear shatterproof goggles when handling
the CRT to protect eyes in case of implosion.
X-RAX-RA
X-RA
X-RAX-RA
Be aware of the instructions and procedures covering X-ray radiation. In
solid-state receivers and monitors, the CRT is the only potential source of
X-rays. Keep an accurate high voltage meter available at all times. Check
meter calibration periodically. Whenever servicing a receiver, check the
high voltage at various brightness levels to be sure it is regulating
properly. Keep high voltage at rated value, NO HIGHER. Excessive high
voltage may cause X-ray radiation or failure of associated components.
DO NOT depend on protection circuits to keep voltage at rated value.
When troubleshooting a receiver with excessive high voltage, avoid close
contact with the CRT. DO NOT operate the receiver longer than
necessary. To locate the cause of excessive high voltage, use a variable
AC transformer to regulate voltage. In present receivers, many electrical
and mechanical components have safety related characteristics which are
not detectable by visual inspection. Such components are identified by a
# on both the schematic and the parts list. For SAFETY, use only
equivalent replacement parts when replacing these components.
GENERAL GUIDELINESGENERAL GUIDELINES
GENERAL GUIDELINES
GENERAL GUIDELINESGENERAL GUIDELINES
Perform a final SAFETY CHECK before returning receiver to customer.
Check repaired area for poorly soldered connections, and check entire
circuit board for solder splashes. Check board wiring for pinched wires or
wires contacting any high wattage resistors. Check that all control knobs,
shields, covers, grounds, and mounting hardware have been replaced. Be
sure to replace all insulators and restore proper lead dress.
WARNINGWARNING
VICE
WARNING
VICE VICE
WARNINGWARNING
VICING VICING
VICING
VICING VICING
Y RADIAY RADIA
Y RADIA
Y RADIAY RADIA
THE HIGH THE HIGH
THE HIGH
THE HIGH THE HIGH
TION AND HIGH TION AND HIGH
TION AND HIGH
TION AND HIGH TION AND HIGH
VV
OLOL
V
OL
VV
OLOL
TT
AA
GE AND CRGE AND CR
T
A
GE AND CR
TT
AA
GE AND CRGE AND CR
VV
OLOL
TT
V
OL
T
VV
OLOL
TT
TT
T
TT
AA
GE LIMITSGE LIMITS
A
GE LIMITS
AA
GE LIMITSGE LIMITS
UTIONSUTIONS
UTIONS
UTIONSUTIONS
SAFETY CHECKS — FIRE AND SHOCK HAZARDSAFETY CHECKS — FIRE AND SHOCK HAZARD
SAFETY CHECKS — FIRE AND SHOCK HAZARD
SAFETY CHECKS — FIRE AND SHOCK HAZARDSAFETY CHECKS — FIRE AND SHOCK HAZARD
Cold LeakaCold Leaka
Cold Leaka
Cold LeakaCold Leaka
Unplug the AC cord, connect a jumper across the plug pr ongs, and turn
the power switch on (if applicable). Use an ohmmeter to measure the
resistance between the jumped AC plug and any exposed metal cabinet
parts such as antenna screw heads, control shafts, or handle brackets.
Exposed metal parts with a return path should measure between 1M
ohms and 5.2M ohms. Parts without a return path must measure infinity.
Hot LeakaHot Leaka
Hot Leaka
Hot LeakaHot Leaka
Plug the AC cord directly into an AC outlet. DO NOT use an isolation
transformer. Use a 1500 ohms, 10W resistor in parallel with a .15µF
capacitor to connect between any exposed metal parts on the receiver and
a good earth ground. (See figure below.) Use an AC voltmeter with at
least 5000 ohms per volt sensitivity to measure the voltage across the
resistor. Check all exposed metal parts and measure voltage at each point.
Voltage measurements should not exceed .75VAC, 500µA. Any value
exceeding this limit constitutes a potential shock hazard and must be
corrected. If the AC plug is not polarized, reverse the AC plug and repeat
exposed metal part voltage measurement at each point.
gg
e Chece Chec
e Chec
e Chece Chec
ks fks f
ks f
ks fks f
g
gg
gg
e Current Chece Current Chec
g
e Current Chec
gg
e Current Chece Current Chec
or Receiveror Receiver
or Receiver
or Receiveror Receiver
kk
k
kk
s with Isolated Grs with Isolated Gr
s with Isolated Gr
s with Isolated Grs with Isolated Gr
oundound
ound
oundound
4733
SET 4733SET 4733
SET 4733SET 4733
SET 4733
Error Codes Chart .................................. 1
GridTrace Location
High Voltage Shutdown Test.................. 1
IC Functions ........................................... 2
Important Parts Information ................... 4
Miscellaneous Adjustments.................... 1
Parts List................................................. 4
Placement Chart ..................................... 1
Safety Precautions.................................. 1
Schematic Component Location ............ 3
Schematic Notes ..................................... 2
Schematics
Test Equipment....................................... 1
Tuner Information .................................. 1
INDEXINDEX
INDEX
INDEXINDEX
Main Board ..................................... 4
Audio ............................................... 3
Comb Filter ..................................... 3
Gemstar 4 ........................................ 3
Power Supply .................................. 2
Television ........................................ 2
Technical Service Data
RCARCA
RCA
RCARCA
Model G27648YX1 (Chassis CTC203AA)Model G27648YX1 (Chassis CTC203AA)
Model G27648YX1 (Chassis CTC203AA)
Model G27648YX1 (Chassis CTC203AA)Model G27648YX1 (Chassis CTC203AA)
Representative Model
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or seror ser
f
or ser
ff
or seror ser
Essential coEssential co
Essential co
Essential coEssential co
vicing a televicing a tele
vicing a tele
vicing a televicing a tele
ScSc
hematicshematics
•
Sc
hematics
ScSc
hematicshematics
veravera
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vera
veravera
vision receivervision receiver
vision receiver
vision receivervision receiver
ee
g
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ee
......
...
......
4733
4733
HIGH HIGH
VV
OLOL
TT
AA
HIGH
V
HIGH HIGH
VV
Momentarily short BC14901 (see Q14901 base) to ground. The receiver should lose raster and sound. If
receiver does not lose raster and sound, the shutdown circuit should be repaired. To resume normal
operation, remove AC power for approximately 30 seconds and then turn the receiver on.
The listing of any available replacement part herein in no case constitutes a recommendation, warranty, or guarantee by
SAMS Technical Publishing as to the quality and suitability of such replacement part. The numbers of the listed parts have
been compiled from information furnished to SAMS Technical Publishing by the manufacturers of the specific type of
replacement part listed.
Reproduction or use, without express permission, of editorial or pictorial content, in any manner, is prohibited. No patent
liability is assumed with respect to the use of the information contained herein.
© 2003 SAMS Technical Publishing LLC
9850 East 30th Street
Indianapolis, IN 46229
Printed in the United States of America 5 4 3 2 1
PP
aa
gg
e 1e 1
a
g
e 1
aa
gg
e 1e 1
SET 4733 SET 4733
SET 4733
SET 4733 SET 4733
P
PP
GE SHUTDOGE SHUTDO
OL
T
A
GE SHUTDO
OLOL
TT
AA
GE SHUTDOGE SHUTDO
WN WN
TESTTEST
WN
TEST
WN WN
TESTTEST
03PF02123
UPC
HERE
MODEL G27648YX1 (CHASSIS CTC203AA)MODEL G27648YX1 (CHASSIS CTC203AA)
MODEL G27648YX1 (CHASSIS CTC203AA)MODEL G27648YX1 (CHASSIS CTC203AA)
MODEL G27648YX1 (CHASSIS CTC203AA)
RCARCA
RCARCA
RCA
For Supplier AdFor Supplier Ad
For Supplier Ad
For Supplier AdFor Supplier Ad
See PHOSee PHO
See PHO
See PHOSee PHO
TT
T
TT
OFOF
OF
OFOF
AA
CT AnnCT Ann
A
CT Ann
AA
CT AnnCT Ann
dress,dress,
dress,
dress,dress,
ual Indeual Inde
ual Inde
ual Indeual Inde
xx
x
xx
Component locationsComponent locations
•
Component locations
Component locationsComponent locations
PP
arar
ts listts list
•
P
ar
ts list
PP
arar
ts listts list
Coverage includes these additional models and chassis:
ModelsModels
Models
ModelsModels
G27648YX51 CTC203AA5
G27648YX51 CTC203AA9
G27648YX52 CTC203AA5
G27648YX52 CTC203AA9
JUNE JUNE
2003 SET 4733 2003 SET 4733
JUNE
2003 SET 4733
JUNE JUNE
2003 SET 4733 2003 SET 4733
ChassisChassis
Chassis
ChassisChassis
PP
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SET 4733 SET 4733
SET 4733
SET 4733 SET 4733
P
a
PP
aa
TUNER INFORMATION
TUNER TUNER
TUNER
TUNER TUNER
PinPin
Pin
PinPin
(1) AGC 2.5V 2.5V 3.0V
(2) NC 1.3V 4.3V 5.7V
(3) +5V 5.2V 5.2V 5.2V
(4) CLOCK 5.1V 5.1V 5.1V
(5) DATA 5.1V 5.1V 5.1V
(6) +5V 5.2V 5.2V 5.2V
(7) +5V 5.2V 5.2V 5.2V
(9) +32V 34.5V 34.5V 34.5V
(11) IF 0V 0V 0V
NOTE: VHF Low Band voltages taken on channel 2.
VHF LoVHF Lo
VHF Lo
VHF LoVHF Lo
VHF High Band voltages taken on channel 7.
UHF Band voltages taken on channel 14.
w Bandw Band
w Band
w Bandw Band
VV
OLOL
TT
V
OL
T
VV
OLOL
TT
AA
GE CHARGE CHAR
A
GE CHAR
AA
GE CHARGE CHAR
VHF High BandVHF High Band
VHF High Band
VHF High BandVHF High Band
TT
T
TT
UHF BandUHF Band
UHF Band
UHF BandUHF Band
TUNER TUNER
TUNER
TUNER TUNER
(2)
(4)
(6)
TERMINAL GUIDETERMINAL GUIDE
TERMINAL GUIDE
TERMINAL GUIDETERMINAL GUIDE
(1)
t
t
(3)
t
t
(5)
t
t
(7)
t
(9)
t
(11)
t
MISCELLANEOUS ADJUSTMENTS
NOTE: All procedures require an antenna connected and power applied
to the set.
HIGH HIGH
VV
OLOL
TT
AA
HIGH
V
HIGH HIGH
VV
Tune in a picture. Set brightness, contrast, and color to minium. Connect
a high voltage probe to the CRT anode. High voltage should measure
between 26kV and 28kV.
SERSER
VICE MENUVICE MENU
SER
VICE MENU
SERSER
VICE MENUVICE MENU
The following adjustment procedures are accessed thru a service menu. To access the service menu, turn the receiver on, press the menu button
and hold it down while pressing the power button. While holding down the menu button, release the power button and press the volume +
button. The screen will display a one line menu, on the left the parameter P0, and on the right the value of that parameter V0. Release buttons.
Adjustments are made by selecting the proper parameter and changing the value of that parameter. To change the parameter number use channel
up and down buttons. To adjust the current value of that parameter use volume + and - buttons. To access and change any of the adjustments, the
proper parameter pass number must be entered. This information is listed at the beginning of the alignment. When these parameters are
modified, the T-Chip and the corresponding EEPROM are updated. All service adjustments are bus controlled, except focus and screen.
NOTE: In order to adjust the RF AGC, audio or video levels, tuner, PIP, or stereo circuits, the ChipperCheck hardware and software must be
used. This can be purchased from Thomson Electronics. Before making any changes to any of the values, record the On Set values.
SERSER
VICE ADJUSTMENT PARAMETERSVICE ADJUSTMENT PARAMETERS
SER
VICE ADJUSTMENT PARAMETERS
SERSER
VICE ADJUSTMENT PARAMETERSVICE ADJUSTMENT PARAMETERS
PP
arameterarameter
P
arameter
PP
arameterarameter
No.No.
No.
No.No.
GE CHECKGE CHECK
OL
T
A
GE CHECK
OLOL
TT
AA
GE CHECKGE CHECK
PP
arameter Namearameter Name
P
arameter Name
PP
arameter Namearameter Name
On SetOn Set
On Set
On SetOn Set
VV
aluealue
V
alue
VV
aluealue
VV
aluealue
V
alue
VV
aluealue
RangRang
Rang
RangRang
COLOR COLOR
COLOR
COLOR COLOR
NOTE: See Service Adjustment Parameters to change drive and bias
values.
Press menu button for collapsed raster service line. Disconnect the
antenna. Preset the red, green, and blue drive values to 32. Adjust
screen control for a service line that is just visible. Adjust red,
green, and blue drives to obtain a white raster. Check the low light
to high light gray scale tracking. Repeat the procedure, if necessary, to obtain the best performance.
ee
e
ee
TEMPERATEMPERA
TEMPERA
TEMPERATEMPERA
CommentComment
Comment
CommentComment
TURETURE
TURE
TURETURE
0 Pass number for service Must set to 76 - May not advance until value is set to 76.
adjustment parameters.
1 Error Code 1 0 0 - 255 Displays the first error detected. Set to 0 before exiting.
See Error Codes Chart.
2 Error Code 2 0 0 - 255 Displays the second error detected. Set to 0 before exiting.
See Error Codes Chart.
3 Error Code 3 0 0 - 255 Displays the last error detected. Set to 0 before exiting.
See Error Codes Chart.
4 Horizontal Phase 10 0 - 15 Tune in a crosshatch pattern, adjust to center the pattern on
the screen.
5 EW DC (Width) 16 0 - 31 Tune in a crosshatch pattern, adjust for slight horizontal
overscan.
6 EW Amplitude 8 0 - 15 Set value to 8.
7 EW Tilt 8 0 - 15 Set value to 8.
8 Top Corner Pin Correction 2 0 - 7 Set value to 2.
9 Bottom Corner Pin Correction 2 0 - 7 Set value to 2.
10 Vertical DC 33 0 - 63 Tune in a crosshatch pattern, adjust to center vertically.
11 Vertical Size 84 0 - 127 Tune in a crosshatch pattern, adjust for slight vertical
overscan.
12 Vertical Countdown Mode 0 0 - 3 Set value to 0. ( 0 = Standard, 1 = Non-Standard, 2 = 50Hz,
3 = 48Hz )
13 Red Bias 30 0 - 127 Press menu button on the TV set for setup line.
14 Green Bias 15 0 - 127 Press menu button on the TV set for setup line.
15 Blue Bias 34 0 - 127 Press menu button on the TV set for setup line.
16 Red Drive 41 0 - 63 17 Green Drive 33 0 - 63 18 Blue Drive 32 0 - 63 19 Gemstar Horizontal OSD Position 166 0 - 255 Set value to 166.
20 Gemstar Vertical OSD Position 68 0 - 255 Set value to 68.
21 Gemstar PIP Horizontal Position 40 0 - 255 Set value to 40.
22 Gemstar PIP Vertical Position 43 0 - 255 Set value to 43.
23 Gemstar PIP Window Vertical Size 3 0 - 13 Set value to 3.
SET 4733 PSET 4733 P
SET 4733 P
SET 4733 PSET 4733 P
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a
g
e 1
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ERROR CODES CHART
ErrErr
or Codeor Code
Err
or Code
ErrErr
or Codeor Code
DECDEC
DEC
DECDEC
0 00 No error code 1 01 16.0V fault 16.0V STBY source is failing.
3 03 12.0V run fault 12.0V source is failing.
4 04 T4 Chip Run supply failed.
8 08 T4 Chip X-ray protection caused high voltage shutdown.
9 09 T4 Chip (POR) Power supply problem at (POR) power on reset.
10 0A F2 PIP module error (POR) Power supply problem at (POR) power on reset/PIP.
11 0B Stereo decoder (POR) Power supply problem at reset/Stereo decoder.
16 10 Run IIC Bus held low Run IIC clock or data held low.
18 12 Standby IIC Bus held low Standby IIC clock or data held low.
23 17 Gemstar 4 Board Guide fatal error on set using Gemstar 4 Board.
24 18 Gemstar 4 Board Watchdog error on set using Gemstar 4 Board.
25 19 Gemstar 4 Board Task monitor error on set using Gemstar 4 Board.
26 1A Gemstar 4 Board Task monitor error on set using Gemstar 4 Board.
32 20 Gemstar 4 Board CPU error on set using Gemstar 4 Board.
34 22 Gemstar 4 Board Gemstar fails to acknowledge.
44 2C F2 PIP module error F2PIP fails to acknowledge.
102 66 Octal DAC Octal DAC fails to acknowledge.
128 80 Stereo decoder Stereo decoder fails to acknowledge.
160 A0 Main or PIP tuner EEPROM Main or PIP tuner EEPROM fails to acknowledge.
186 BA T4 Chip T4 Chip fails to acknowledge.
196 C4 Main tuner PLL/DAC Main tuner PLL IC fails to acknowledge.
198 C6 Main tuner PLL/DAC Main tuner DAC IC fails to acknowledge.
ERRERR
OR CODESOR CODES
ERR
OR CODES
ERRERR
OR CODESOR CODES
HEX HEX
HEX
HEX HEX
ErrErr
or Locationor Location
Err
or Location
ErrErr
or Locationor Location
Condition IndicatedCondition Indicated
Condition Indicated
Condition IndicatedCondition Indicated
TEST EQUIPMENT
Test equipment listed by participating manufacturer illustrates
typical or equivalent equipment used by Sams engineers to obtain
measurements. This equipment is compatible with most types used
by field service technicians.
EquipmentEquipment
Equipment
EquipmentEquipment
Oscilloscope SC3100
Generators
RGB CM2125
Multiburst Signal VG91
Color Bar VG91
TV Stereo VG91
Digital VOM SC3100
Frequency Meter SC3100
Hi-Voltage Probe HP200
Accessory Probes TP212
Isolation Transformer PR570
Capacitance Analyzer LC102
CRT Analyzer CR7000
AC Leakage Tester PR570
Inductance Analyzer LC102
Flyback Y oke Tester TV A92
Field Strength Meter SL753
Transistor Tester TF46
Horizontal Analyzer HA-2500
Video Analyzer VG91, TVA92
Sencore No.Sencore No.
Sencore No.
Sencore No.Sencore No.
If certain failures occur, the matching error codes will be stored in the EEPROM. These error codes will be displayed in parameters 1, 2, and 3. The first
failure error code will be stored at parameter 1 and the second failure error code will be stored at parameter 2. Parameter 3 will be updated to display the
most recent failure occurred in the chassis. If a failure of a bus IC occurred, the normal acknowledgment checking of that bus will be disabled in the
service mode and the address of that IC which failed will be stored in one of the error code parameters. After every repair is done to the chassis it is
recommended to check the error code parameters, and reset them back to value 0.