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CTC203
TROUBLESHOOTING
Main Troubleshooting Flow Chart
Dead Set 7-2
EEPROM Error Codes 7-3
System Control 7-4
Power Supply 7-5
Horizontal 7-6
Vertical 7-7
Tuner 7-8
Tuner Band Switching 7-9
Color 7-10
Video 7-11
Buttons 7-12
Infrared 7-12
OSD 7-13
Gemstar 7-14
F2PIP 7-15
Analog Comb 7-16
General Audio Problems 7-18
Distorted Audio 7-20
Stereo Seperation 7-20
No Stereo 7-21
Sound Logic 7-22
Page 7-1 Return To Main Flow Chart
CTC203
TROUBLESHOOTING
DEAD SET TROUBLESHOOTING
Set Will Not Turn On
Degauss Relay
Switching Check EEPROM Error Codes
YES
ON/OFF? Using Chipper Check
NO
Microprocessor
U13101 Reset YES Check System Control
Pin 51 = 5V?
NO
Check Power Supplies
Page 7-2 Return To Main Flow Chart
CTC203
TROUBLESHOOTING
EEPROM Error Codes
Error code: Chassis: Error: Action
HEX DEC POWER CONTROL ERRORS
00 0 ALL No Errors
01 1 ALL 16V_STBY fault Check Power Supplies
03 3 ALL 12V_RUN fault Check Power Supplies
08 8 ALL T4chip XRP (X-ray protection) Check Power Supplies
09 9 ALL T4chip POR (power on reset) Check Horizontal
0A 10 w/ F2PIP F2PIP POR Check F2PIP
0B 11 ALL Stereo Decoder POR Check General Audio
10 16 ALL Run I2C bus latched Check System Control
12 18 ALL Standby I2C bus latched Check System Control
HEX DEC I2C ACKNOWLEDGE ERRORS
22 34 w/Gemstar Failure to get acknowledge from Gemstar module Check Gemstar
2C 44 w/ F2PIP F2PIP fault Check F2PIP
66 102 w/Gemstar Gemstar bus fault Check Gemstar
80 128 ALL Stereo Decoder fault Check General Audio
A0 160 EEPROM EEPROM bus fault Check System Control
BA 186 ALL T4chip fault Check System Control
C4 196 ALL Main Tuner PLL bus fault Check Tuner
C6 198 ALL Main Tuner DAC bus fault Check Tuner
Page 7-3 Return To Main Flow Chart
CTC203
TROUBLESHOOTING
System Control Troubleshooting
Microprocessor
U13101 Check Micro Reset Circuit.
NO
Pin 51 = 5V? Q13501, Q13503, etc.
YES
Check R13128,
EEPROM R13181,Q13104.
U13102 U13101 U13101 Pin 20
Pin 8 = 5V?
NO
Pin 20 ~4.5V? NO should be High
YES
YES Impedance. If
not replace.
Replace Q13104
Microprocessor
U13101 Replace 4MHz Crystal Y13101,
NO
Pins 40,42 = 4MHz? R13107,C13106,C13107
YES
Plug in AC. Check Bus
Activity on U13101 Pins
Check EEPROM and Power
23,24. Do Transmissions NO
Stop after a few moments? Supplies
YES
Microprocessor
U13101 KD1
Pin 5 = 5V Pulse?
NO Check Power Supply
YES
Note: Pin 5, Drive
Line, should have a Microprocessor
20ms pulse. If this U13101 Sense Lines Check Front Panel for Stuck or
pulse is seen on a Pins 6,7,8 = Steady NO Shorted Button or Missing 5V.
sense line then a 5V with No pulses?
YES
button is closed.
Check EEPROM Error Codes
Using Chipper Check
Page 7-4 Return To Main Flow Chart
CTC203
TROUBLESHOOTING
Power Supply Troubleshooting
Raw B+
@TP14210 NO
Check F14201, R14202,
~ 150V ? CR14201-CR14204
YES
+16V stanby
Cathode CR14108 NO Check CR14108
~ 16V?
YES
RegB+ Cathode
CR14106 Check RegB+ Circuit. R14116,U14101,U14102,
NO
~ 130V? Q14102,Q14103,Q14106,Q14107,Q14101
YES
+5V stanby
U14103 Pin 1
U14103 Pin 3 NO
~ 14.8V? NO Check CR14110
~ 5.2V? YES
YES
Replace Q14104,Q14105
Replace U14103
+12V Switch YES
U14104 Pin 3 U14104 Pin 1 U13101 Pin 19~5V
NO ~ 16V? NO with Power Button
~ 12.2V? Pressed?
If the Degaus YES
YES
NO
Relay is clicking
then the +12Vs Replace U14104
and +7.5Vs will Troubleshoot System
be ON only Control
momentarily at
turn ON. +7.5V Switch
U14150 Pin 3 U14150 Pin 1
NO ~ 10V? NO Check R14151
~ 7.3V?
YES
YES
Replace U14150
Power Supplies OK
Page 7-5 Return To Main Flow Chart
CTC203
TROUBLESHOOTING
Horizontal Troubleshooting
NOTE: If the Set is going into XRP shutdown the Degaus Relay will click
and the pulses below will only be present momentarily at turn ON
T4 Chip
U12101 NO Check U14150
Pin20 =7.6V?
YES
T4 Chip U12101 T4 Chip U12101 Troubleshoot
Pin 22 =7.2Vp-p Bus Activity on
NO NO System
Square Wave? Pins 43, 44? Control
YES YES
Replace U12101
(See Note at Top)
Q14302 Emitter
= 5.3Vp-p NO Replace Q14302
Square Wave?
YES
Q14301Collector
= 224Vp-p ? NO Replace Q14301
YES
Q14401 Base With Set OFF is
there Continuity Replace
~ 3.1Vp-p? NO NO
T14301
in T14301?
YES YES
Check Base Components
Q14401
Collector Check Bad Q14401, Shorted or open
NO
= 1060 Vp-p? T14401, Bad Horizontal Yoke Winding.
YES
Check C14403, CR14403 and RegB+.
EEPROM Code
indicates XRP Horizontal Test
Fault?
NO
Complete
YES
Check XRP Circuitry Q14901, CR14902,
R14902, R14903, R14905
Page 7-6 Return To Main Flow Chart
CTC203
TROUBLESHOOTING
Vertical Troubleshooting
T4 Chip U12101 T4-Chip
Pin 15 ~2.4V NO
U12101 Pin Check U14150
NO
Sawtooth ? 26 =7.6V?
YES
YES
T4-Chip
U12101 Pin Check R14153
NO
20 =7.6V?
YES
Reinitialize EEPROM Vertical
Settings. Replace U12101 if Reinit
doesn't work
U14501 Pin 1
~2V Parabola ? NO Replace RN14501
YES
U14501
Pin 2 ~ 23V? NO Troubleshoot Power Supply
YES
U14501
Pin 6 ~ 23V? NO Check CR14501
YES
U14501
Pin 3 ~ 1.5V? NO Replace U14501
YES
U14501 Pin 5
~50V Vertical NO Replace U14501
Ramp?
YES
Check Connection P14501
and Choke Continuity
Page 7-7 Return To Main Flow Chart
CTC203
TROUBLESHOOTING
Tuner Troubleshooting
NOTE: If the GEMSTAR is set up to use a DSS or Cable Box the Tuner may be locked
to the input channel for that device. The OSD will still show a channel change but the
Channel DOES NOT change therefore the tuning voltages will NOT change
Check Supplies to Tuner.
+5,+9,+12,-12,+33
All Supplies
Present? NO Troubleshoot Power Supplies
YES
Does OSD Troubleshoot
Does Set Tune? NO
Change? NO Control System
YES YES
See Note at Top of page
Goto Band Switch U17401 Pins18,19.
Troubleshooting NO
Do All Bands Is There Bus NO Troubleshoot
on next page. Tune? Activity? Control System
YES YES
See Note at Top of page
Check U12101 Does AGC Voltage U17401 Pins 5,6,7,8.
Pin 5 and Are Voltages Close NO
NO Change when Input Replace U17401
components in is Attenuated? To Voltage Chart?
AGC Line. YES YES
Use Chipper Check to U17301 Pin 11.
Check Tuner alignment Does Voltage
and EEPROM Values change with NO Replace Q17402
Bands?
YES
Does AGC Voltage
Change when Input NO Replace U17301
is Attenuated?
YES
Troubleshoot Video
Page 7-8 Return To Main Flow Chart
CTC203
TROUBLESHOOTING
Tuner Troubleshooting (continued)
Troubleshoot Band Switches
Check Supplies to Tuner.
+5,+9,+12,-12,+33
See Note at Top of previous page
U17401 Pins 5,6,7,8.
Are Voltages Close NO Replace U17401
To Voltage Chart?
YES
Q17404
Switching NO Replace Q17404
Voltages Correct?
YES
Q17402
Switching NO Replace Q17402
Voltages Correct?
YES
Set Tunes Replace CR17101, CR17114,
Band 3? NO CR17102, CR17103, CR17301,
CR17304 & Q17101
YES
Set Tunes Q17403
Either Band NO
Switching NO Replace Q17403
1 or 2? Voltages Correct?
YES YES
Check Diodes CR17105, CR17112, Replace CR17106, CR17107,
CR17109, CR17110, CR17303. CR17108, CR17111, CR17113,
Replace as needed CR17302 & Q17102.
Page 7-9 Return To Main Flow Chart
CTC203
TROUBLESHOOTING
Color Troubleshooting
No Color
U12101 Pin 42 Check Input Signal strength.
Color Burst > NO Troubleshoot Tuner if strong
200mV?
YES
signal is attached to input.
U12101 Pin 40
Color Burst >
NO Troubleshoot Video Module
100mV?
YES
NOTE: Color Killer is active if Pin 39 ~1.5V
U12101 Pin 39 Check R12801, R12802, R12804 and
Color Killer NO C12801. If components are good
~3.5V?
YES
Replace U12101
U12101 Pin 13 Check attached components and for
Chroma APC NO
~5.5V?
7.6VrA
YES
U12101 Pin 41 Check attached components and for
Test Filter NO
~5.5V? 7.6VrF
YES
Replace U12101
Page 7-10 Return To Main Flow Chart
CTC203
TROUBLESHOOTING
Video Troubleshooting
No Video
U12101 Pin 42 Check Input Signal strength.
~ 2Vp-p? NO Troubleshoot Tuner if strong
YES
signal is attached to input.
U12101 Pin 38 Troubleshoot Video Module
~ 1Vp-p-? NO
(F2PIP or Analog Comb)
YES
U12101 Pin 30,
31,32 ~ 2.5Vp-p
Video Signal?
NO Replace U12101
YES
Video present at
collectors of
Q12701, Q12702, NO Replace Faulty Transistors
Q12703?
YES
Check that pins in connec-
tor are soldered properly.
12VrK Present at
bases of Q12701, NO Troubleshoot 12V supply
Q15102, Q15103?
YES
Video present at
collectors of
Q15101, Q15102, NO Replace Faulty Transistors
Q15103?
YES
Check the CRT Screen
Control and that the
Filaments are glowing.
Page 7-11 Return To Main Flow Chart
CTC203
TROUBLESHOOTING
User Interface Troubleshooting
If a Button is shorted or stuck closed the set will not
respond to either the Remote Control or Button Press.
Set does not respond to some
button presses.
U13101Pin5
~ 20ms Square Troubleshoot System Control
NO
Wave?
YES
U13101 Pin 6,7,8 Check 5V and R13113,
= 5V? NO
R13118, R13119.
YES
When Power, Volume Up, or Volume Down is pressed there should be ~20ms
low pulse on their respective sense line. If pulse is not present check for a
bad switch. If Channel Up, Channel Down or Menu is pressed their respec-
tive sense line should go Low for the duration of the button press. If not
check for a bad switch.
Set does not respond to
Remote Control.
Set Responds to
all buttons? NO Troubleshoot Buttons
YES
5V at VCC Pin of
IR receiver? NO Troubleshoot Power Supply
YES
~5Vp-p Transmis-
sion at Output Pin NO Replace IR Receiver
of IR receiver?
YES
Troubleshoot System Control
U13101 Pin 36.
Page 7-12 Return To Main Flow Chart
CTC203
TROUBLESHOOTING
OSD Troubleshooting
Set does not have Channel
Numbers or Menus
U13101Pin 35
Horizontal
Present?
NO Check Q13301
YES
U14150 Pin 3 ~
1.5V? NO Replace U14150
YES
U13101 Pin 34
Check Pin 3 U14150, JC14105,
Vertical Present ? NO
13320, R13314.
YES
Press "Menu".
U13101Pin 26,
27,28 is OSD NO Replace U13101
Present?
YES
Press "Menu".
U12101Pin 34,
Check components between
35, 36 is OSD NO
Present? U13101 and U12101
YES
If Video is normal replace U12101.
If Video is missing Troubleshoot
Video
Page 7-13 Return To Main Flow Chart
CTC203
TROUBLESHOOTING
GEMSTAR Troubleshooting
Tune set to a channel with valid GEMSTAR program information on the
Vertical Blankin Interval (VBI). Gemstar is auto-detected by the micro-
processor. Select the Main menu. If GEMSTAR has been detected there
will be a menu item "Guide Plus+ Menu".
If item is not present check
Main Menu Module Cables the cable(s) to the GEMSTAR
displays "GUIDE seated Properly module to make sure they are
NO NO
PLUS+ Menu" ? ? seated properly. Select the
YES
menu again, item will show up
YES
if this was the problem.
+5.2V present
U26401 pins 12, Troubleshoot +5.2V network
24, 31, 42, 51, NO
and supply
61, 65, 73?
YES
4.03MHz OSC
Check for proper components
on U26401 Pins
NO and that all parts are soldered.
66,67?
Replace Y26401.
YES
Pulsed Bus Check bus lines and compo-
activity on U26401 NO nents and that all parts are
Pins 69, 70? soldered.
YES Check U13101 pins 13,14.
Replace U26401
GUIDE Menu is Vertical present on Check line and components
present ? NO U26405 pin 2 ? NO back to J13103.
Troubleshoot Vertical.
YES YES
Vertical present on
U26401 pin 36 ? NO Replace U26405
YES
Horizontal
present on Check Q26403
NO
U26401 pin 39 ?
YES
NEXT PAGE
Page 7-14 Return To Main Flow Chart
CTC203
TROUBLESHOOTING
GEMSTAR Troubleshooting (cotinued)
FROM PREVIOUS PAGE
U26401Reset pin Check line to J13103.
71 ~5.2V ? NO
Troubleshoot System Control
YES
Check components attached
to U26401pins 62,63. These
control the OSD dot clock.
RGB present
U26401 pins NO Replace U26401
48,49,50?
YES
FSW present
U26401 pin 53 ? NO Replace U26401
YES
Check Connector J13103
Troubleshoot Video
Make sure set is tuned to GEMSTAR data provider. Select
Valid Data "MainMenu", select "GUIDE Plus+ Menu", select
Stored in NO "GUIDE Plus+ Setup". On the Remote Control Press
GUIDE ? "Go Back" and then "TV". This will bring up the Factory
YES Diagnostic Screen.
ROM Test
Passed? NO Replace U26402
YES
RAM Test
Passed? NO Replace U26403
YES
VBI Test
Passed? NO Tuned to Non-VBI channel?
Check Q26405 composite
YES
Video also Q26404,Q26408
which supply sync during "set
Check Owners manual on GIUDE Plus+ Setup off" downloads.
procedures.
Page 7-15 Return To Main Flow Chart
CTC203
TROUBLESHOOTING
F2PIP Troubleshooting
EEPROM Error indicates a
F2PIP error.
Check Y18100, 14.318MHz
Does set turn crystal. Should be within 1Khz
ON?
NO
of nominal to guarantee
YES proper operation
Check 3.3V supply.
Set has a Main Check Data and Clock Lines.
Picture? NO
Check main Video Signal path.
YES If above is good replace U18100
PIP Turns ON? Check for proper Vert. &
Horz. Sync at U18100 Pin 24
NO
YES
PIP Picture Check PIP contrast and
Visible? NO Brightness alignments.
YES
Check PIP signal Path
PIP Picture
Distorted ? NO PIP Normal
YES
Use Chipper Check to check
PIP Alignments.
Page 7-16 Return To Main Flow Chart
CTC203
TROUBLESHOOTING
Analog Comb Troubleshooting
Connect a signal generator to the Tuner Input and to
the Video Input Jack. Check 5V and 12V supplies.
U26903
Pin 6 = TV NO Troubleshoot Video Signal
Video Signal
YES
U26903
Pin 3 = Input NO
Check R11406, C11403,
Video Signal R26921
YES
U26903 Pin 4 Check Q26903 and insure that
0V =TV Video NO
switching voltage is present
5.1V = Input Video
from U13101
YES
U26903 Pin 8.
Signal can be
Luma
switched between TV
NO Replace U26903
Video and Input
Video?
YES
Luma & Chroma
present at Pins 3
NO Replace FL2601
& 5 on FL2601
YES
Chroma present at
Pin 8 U26902 NO Replace U26902
YES
Chroma
Luma present at Luma present at Replace
Pin 6 J26901 NO Pin 8 U26901 NO
U26901
YES YES
Analog Comb OK Replace Q26901
Page 7-17 Return To Main Flow Chart
CTC203
TROUBLESHOOTING
General Audio Troubleshooting
Connect a generator to the set. Adjsut "Sound Processor" Menu to "Speak-
ers ON", Fixed Level Mode OFF", "Sound Logic OFF".
Sound Quick Checks:
1. Check that Speaker's plug is seated properly.
2. Check that the "Speakers" are turned ON & "Fixed Level Mode"is OFF
3. Check that Balance is Centered.
4. Check if there is audio present at Audio Output Jacks to isolate problem.
EEPROM Error Does set turn Check 9V regulator Q11603.
code indicates Audio ON? NO Check U11601 Bus lines
Problem. YES
Pins 9,10 .
Wide Band
Audio present at
Pin 17 U11601 ? NO
Check C11601, Pin 6 U12101
YES
U11601 Pin 39,
40 Audio
NO
ABSENT ?
YES
Check menu items again. Send
Volume Up Command.
U11601 Pin 22
Vcc~ 9.4V ? NO Check Q11603
YES
U11601 Pin 12, 13,
17, 39, 40 Bias NO Replace U11601
Voltage~ 4.1V ?
YES
U11601 Pin 12,
13, Audio NO Replace U11601
Present ?
YES
Go To Next Page
Page 7-18 Return To Main Flow Chart
CTC203
TROUBLESHOOTING
Genearl Audio Troubleshooting (continued)
Set Volume To Max
U11601 Pins 7, 8 U11601 Pins 1, 8
Audio Present? NO Bias ~4.1V? NO Replace U11601
YES YES
Components
on U11601 Replace with correct
Pins 1-4,7, 8 NO
components
Correct?
YES
Replace U11601
U11602 Pin 8
U11602 Pins 1, 7 ~+8V and Pin 4 Troubleshoot Power
NO NO
Audio Present? ~ -8V ? Supplies
YES YES
Components
on U11602 Replace with correct
NO
Correct? components
YES
Replace U11602
U11900/11901 +16V Supply
Pin 2 Audio Troubleshoot Power
NO present ? NO
Present? Supplies
YES YES
U11900/11901
Pin 3 Check Q11901, C11909,
NO
>7V ? U13101 Pin 2
YES
U11900/11901
Pin 4 Audio
YES Present NO Replace U11900/11901
( 71mVrms )?
Check Connector J11901
Page 7-19 Return To Main Flow Chart
CTC203
TROUBLESHOOTING
Audio Troubleshooting (Distortion)
Use a standard 1kHz or 3kHz Sine Wave as an input to the Audio System.
Scope Audio at HiFi or Speaker Outputs (whichever is failing) to determine
if distortion is visible. Move back along Audio signal path to determine
where distortion begins. If point of origin cannot be determined check the
things below.
Check for electrolytics installed backwards or solder shorts around U11601.
Anything that can cause shorts or improper bias on the IC pins. Check for
open traces or missing jumper wires.
Check values of R11704/11706. Excessive gain in Expanded Stereo can cause
Loop IN (U11601 Pins 41,41) to be overdriven. This can cause distortion in
All Modes.
Check voltages on Vcc pins at the Audio ICs as well as the power network
that supplies power to the audio circuit for proper voltage levels.
Check that the Pins of all Audio ICs are soldered properly. Unsoldered pins
can cause overheating and shutdown in the output devices.
If Speaker output is distorted but HiFi outputs are not then the problem is
probably in the U11900/11901 circuit area.
Check that coupling capacitors are loaded properly. Check for shorts
around U11900/U11901 and that the devices are not partially MUTED.
No Stereo Seperation
Problems with stereo seperation are mostly due to wrong, missing or back-
ward parts around U11601. Specifically C11605, C11610 and other parts
connected to pins 16, 18, 23, 24, 28, 29, 30 and 34. this can cause failure of
one of the alignments.
Page 7-20 Return To Main Flow Chart
CTC203
TROUBLESHOOTING
Audio Troubleshooting (No Stereo)
Tune to a channel with known good strereo. Set SOUND PROCESSOR
mode to STEREO. Insure set is working with Mono audio signal.
U11601 not locked to strereo pilot or pilot
Set OSD says level to low. Check components at pins 14,
STEREO? NO
15, & 16 for correct values and proper
YES installation.
Stereo signal
@ U11601 Pins
NO Replace U11601
23, 24, 31&32?
YES
Use Chipper Check to view Stereo alignment
U11601 Pins values. Values near one end of the alignment
39,40 Stereo range may indicate wrong or missing compo-
NO
Present? nents. Noisy or improperly aligned SIF or
YES poorly aligned stereo alingment. Attempt to
realign.
U11601 Pins
14,15,16,19,28,29,30 Check components at dbx pins for correct
&34 bias NO values and proper installation. If compo-
correct? nents are correct Replace U11601
YES
U11601 Pins 7,
8 stereo signal
both channels?
NO Replace U11601
YES
U11602 Pins 1
& 7stereo
signal both NO Replace U11602
channels?
YES
U11900/11901
Pin 2, stereo
signal both NO Replace device without signal
channels?
YES
Check connector J11901, P11901
and speakers
Page 7-21 Return To Main Flow Chart
CTC203
TROUBLESHOOTING
Audio Troubleshooting (Sound Logic)
Tune to a channel with strong MONO signal. Connect a DC
voltmeter to cathode of CR11503.
Voltmeter
Check components around U11501 for
reading ~4V ? NO
correct values and proper installation. In-
sure that there is a strong WBAudio Signal
YES at U11601 Pin 17.
Remove Audio input
Voltmeter Check +12V and -12V supplies. Check for
reading <100mV NO missing parts, wrong values or solder prob-
?
lems. Replace U11501
YES
U13101 Pin 37
Voltage same as Check components in Sound logic line be-
NO
@ CR11503 ? tween U13101 pin 37 and CR11503
YES
Sound Logic OK
Page 7-22 Return To Main Flow Chart