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