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Panasonic CT-27C8G Service Manual

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  • Page 2: Safety Precautions

    1. Safety precautions General guidelines An isolation transformer should always be used during the servicing of a receiver whose chassis is not isolated from AC power line. Use a transformer of adequate power rating as this protects the technician from accidents resulting in personal injuryfrom electrical shocks. It will also protect the receiver from being damaged by accidental shorting that may occur during servicing.
  • Page 3 Unplug the A.C. cord and connect a jumper between the two plug prongs.Measure the resistance between the jumpered AC plug and expose metallic parts such as screwheads, antenna terminals, control shafts, etc. If the exposed metallic part has a returnpath to the chassis, the reading should be between 240k and 5.2M .

  • Page 4: Service Notes

    Measure the high voltage. The high voltage should be 29.25 ± 1.25kV. If the upper limit is out of tolerance, immediate service and correction is required to insure safe operation and to prevent the possibility of premature component failure. Horizontal oscillator disable circuit test This test must be performed as a final check before the receiver is returned to the customer.
  • Page 5 1. Put a small amount of solder on the board soldering pads. 2. Hold the chip component against the soldering pads with tweezers or with a miniature alligator clip and apply heat to the pad area with a 30 watt iron until solder flows. Do not apply heat for more than 3 seconds.
  • Page 6 4. Position the new Flat IC in place (apply the pins of the Flat IC to the soldering pads where the pins need to be soldered). Properly determine the positions of the soldering pads and pins by correctly aligning the polarity symbol 5.
  • Page 7 chassis. Connect the test equipment to the proper ground(hot) or (cold) when servicing, or incorrect voltages will be measured. 2.1. X-Ray Protection Circuit Check& Adjustments This test must be performed as final check before the receiver is returned to the customer. If voltages are out of tolerance, immediate service and correction is required to insure safe operation and to prevent the possibility of premature componentfailure.

  • Page 8: Eeprom Replacement

    5. Apply a monoscope pattern. 6. Set customer picture and brightness controls to the minimum. 7. Set current within 50 A to 100 A by changing the picture and bright controls. 8. Slowly increase AC voltage at the input of the isolation transformer and confirm HHS voltage measure 33kV.

  • Page 9: About Lead Free Solder (Pbf)

    the same procedure as step 4. 6. When replacing a new EEPROM be sure to set the correct ID switch values for each model. 7. Once that all 3 registers are set with the correct address value, perform all of the remaining adjustments and servicing. IMPORTANT: Correct ID switch configuration should be input when replacing EEPROM for each television model, otherwise if wrong values are...

  • Page 10: Receiver Feature Table

    opposite side. Suggested Pb free solder There are several kinds of Pb free solder available for purchase. This product uses Sn+Ag+Cu (tin, silver, copper) solder. However, Sn+Cu (tin, copper), Sn+Zn+Bi (tin, zinc, bismuth) solder can also beused. 5. Receiver feature table...

  • Page 11: Board Description Table

    Specifications are subject to change without notice or obligation. Dimensions and weights are approximate. 6. Board description table CT-27G8G / CT-27G8UG BOARD PART NUMBER DESCRIPTION TNP2AH047GA MAIN BOARD TNP2AA122GA CRT BOARD CT-27L8G / CT-27L8UG / CT-27L8SG / CT-27C8G BOARD PART NUMBER DESCRIPTION TNP2AH047GB MAIN BOARD TNP2AA122GA CRT BOARD...
  • Page 12 NOTE When ordering a replacement board assembly, append an “S” to the board number EXAMPLE To order the A Board, for CT-27G8G the replacement board is TNP2AH047GAS. 7. TV Location of controls...

  • Page 13: Location Of Controls (Remote)

    8. Location of controls (remote) 8.1. EUR7713010 Note: For additional information about this remote please refer to the owner’s manual section remote operation, listed on the parts list section. 8.2. EUR7613Z10...
  • Page 14 - 3 screws at the top edge of the receiver. - 1 screw by the A/V jacks. - 1 screw at each lower corner of the receiver. - 1 screw by the Flyback. - 1 screw by the AC cord (only in CT-27C8G models).
  • Page 15 A-Board - Main chassis 1. Slide the chassis completely out of the guide rails. 2. Stand the receiver on its edge. The underside of the board is completely accessible for component replacement. Note: Some tie-wraps that secure the wire dressings may need to be unfastened for chassis removal. C-Board - CRT output The board plugs onto the socket on the CRT neck.
  • Page 16 3. Unplug the CRT 2nd anode button from the main board. 4. Remove the C-Board from the CRT base and unplug the black wires (CRT dag ground) C10 & C11. 5. Disconnect the speakers plug from the A-Board. 6. Lift the main chassis (A-Board) and all mounted boards completely out with the CRT board attached.
  • Page 17 IMPORTANT NOTICE When ordering the CRT, please order CRT and CRT kit also. Please see parts list section for part numbers. 9.2. Back Cover Removal Back Cover (CT-27C8G). Back Cover (CT-27L8G/UG/SG, CT-27G8G/UG)

  • Page 18: Chassis Service Adjustment Procedures

    10. Chassis service adjustment procedures All service adjustments are factory preset and should not require adjustment unless controls and/ or associated components are replaced. Note: Connect the (-) lead of the voltmeter to the appropriate ground. Use IC801’s heat sink when the HOT ground symbol is used. Otherwise, use COLD ground (Tuner shield, IC451’s heat sink or FA2).
  • Page 19 Note: Components and test points within doted areas are located on trace side. B+ voltage check 1. Set the BRIGHT and PICTURE to minimum by using the PICTURE menu. 2. Connect the DVM between C825 (+ side) or TPD14 and cold ground.
  • Page 20 A-BOARD TEST VOLTAGE POINT TPD14 131.0 ± 2.0V SOUND C823 (+) 18.1 ± 1.0V STB12V C827 (+) 12.8 ± 1.0 V 220V TPA14 217 ± 10 V VERTICAL TPD8 27.4 ± 1.5V IC551 pin 3 9.0 ± 0.5V IC552 pin 3 5.0 ±...
  • Page 21 5. Adjust VOLUME to minimum (0). 6. Press VOL (decrease) on receiver. Red “CHK” appears in upper corner. To toggle between aging and service modes: While the “CHK” is displayed on the left top corner of the CRT, pressing “ACTION” and “VOL” UP on the TV simultaneously will toggle between the modes.
  • Page 22 If service mode is accessed by this method be sure to reset the set after service is performed. 11.1. Service adjustment default values for items NAME DESCRIPTION REGISTER VALUE CT-27C8G CT-27G8G/UG CT-27L8G/UG/SG MTSIN MTS INPUT LEVEL SEPAL MTS LOW LEVEL SEPARATION...

  • Page 23: Service Adjustments (Electronic Controls)

    NAME DESCRIPTION REGISTER VALUE CT-27C8G CT-27G8G/UG CT-27L8G/UG/SG ID2* ID SWITCH 2 ID3* ID SWITCH 3 IMPORTANT: These table values are approximated and could change due to variation of electrical characteristics in each set, except for the ID switch values. *Note: The correspondent ID switch (ID1,ID2, ID3) data configuration should not be modified in any way.
  • Page 24 GND level at TP35. (See waveform detail). 2. In service mode, select DAC for contrast adjustment “CONT”, and adjust data to obtain between 7.5IRE and 100IRE level at TP35. (See waveform detail) 12.2. Color output adjustment / Service DAC adjustment (COLOR, TINT) NOTE if a rainbow pattern generator is available perform the following procedure;...
  • Page 25 3. In service mode adjust “TINT” register until the waveform measured is as the one shown. Tint level from A and B peaks must be almost in the same level (0.35 Vp). TP37 Waveform. 4. Connect the oscilloscope to TP35 and GND. 5.
  • Page 26 3. In service mode adjust “TINT” data so that the color does not become greenish or redish. 4. In service mode adjust “COLOR” data so that the color level is not too high (saturated) or too low (tending to black and white). 5.
  • Page 27 4. Preset the following service DACs for best results: - BRIGH______________________1 D0 - CUT R______________________02 00 - CUT G______________________02 00 - CUT B______________________02 00 - R DR_______________________07 FF - B DR_______________________07 FF PROCEDURE 1. Connect the oscilloscope to KG (CRT-Board). 2.
  • Page 28 12.5. Deflection adjustments To reset deflection adjustments To reset deflection adjustments to factory adjusted default, enter to service mode (with red CHK displayed), press POWER button on remote to display the service menu, then press and hold RECALL button for at least three seconds, a reset messagewill appear in the image. Use this feature when deflection adjustment gets off adjustment to the point that it cannot be adjusted back easily.
  • Page 29 1. Apply a crosshatch pattern 2. Normalize the picture settings. PROCEDURE 1. Enter service mode, select DAC adjustment / “V-POS” and adjust monoscope pattern to the center vertical position of the CRT center mark. 2. Adjust linearity data “V-C” so that interval of “a” is same as “b” (a= 3.

  • Page 30: Identification Of Components

    2. Normalize the picture settings. PROCEDURE 1. Enter to service mode 2. Check a and b sizes, If b-a < -1.5mm (in top & bottom extending case) - Increase “V-S” DATA by one step NOTE Repeat “a” and “b” until b-a ± 1.5mm 3.
  • Page 31 13.1.1. C-Board Chassis C-Board component locations 13.1.2. A-Board Chassis A-Board chassis (Top view)
  • Page 32 13.1.3. A-Board Surface-mounted components A-Board (bottom view)

  • Page 34: Conductor Views

    14. Reference for PDF Colors 15. Conductor Views 15.1. A-Board Printed Circuit (Left Side) 15.2. A-Board& C Board Printed Circuit (Right Side) 16. Block Diagrams 16.1. Video Signal Block Diagram 16.2. Audio Signal Block Diagram 17. Schematics 17.1. English Schematic Notes...
  • Page 36 17.2. Notas de Esquemáticos en Español...

  • Page 38: Parts Location

    17.3. A-Board Schematic TNP2AH047GA/GB (page 1 of 4) 17.4. A-Board Schematic TNP2AH047GA/GB (page 2 of 4) 17.5. A-Board Schematic TNP2AH047GA/GB (page 3 of 4) 17.6. A-Board Schematic TNP2AH047GA/GB (page 4 of 4) 17.7. Voltages 17.8. Waveforms 18. Parts Location 19. Parts List 19.1.
  • Page 39 19.2. Parts List...
  • Page 40 Ref. No. Part No. Part Name & Description Remarks CAPRISTORS CRA801 TP00842-51 TAPING GAP TERMINAL CAPACITORS C003 ECA1HM4R7B CAP E 4.7UF-50V C004 TCJ2VC1H150J CAP C 15PF-J-50V C005 TCJ2VC1H150J CAP C 15PF-J-50V C008 TCJ2VF1H103Z CAP C .01UF-Z-50V C009 ECJ2VF1H104Z CAP C .1UF-Z-50V C010 TCJ2VC1H680J CAP C 68PF-J-50V...
  • Page 41 CAP E 10UF/50V C062 ECA1HM100B CAP E 10UF/50V C063 ECJ2VF1C104Z CAP C .1UF-Z-16V / CT-27G8G CT-27G8UG CT-27L8G CT-27L8UG C063 TCJ2VF1C104Z CAP C .1UF-Z-16V / CT-27L8SG CT-27C8G C064 ECA1CM101B CAP E 100UF/16V C066 TCJ2VC1H330J CAP C 33PF-J-50V C067 TCJ2VC1H680J CAP C 68PF-J-50V...
  • Page 42 Ref. No. Part No. Part Name & Description Remarks C512 ECA2CM100B CAP E 10UF-160V C531 ECA1HM4R7B CAP E 4.7UF-50V C540 TCJ2VF1H103Z CAP C .01UF-Z-50V C551 ECA1VHG471B CAP E 470UF-35V C554 ECKR2H561KB5 CAP C 560PF-K-500V C555 ECA2EM220E CAP E 22UF-250V C556 ECA1CM471B CAP E 470UF-16V C557...
  • Page 43 AP335K016CAE CAP T 3.3UF/16V C2208 ECJ2VB1C104K CAP C .1UF-K-16V / CT-27G8G CT-27G8UG CT-27L8G CT-27L8UG C2208 TCJ2VB1C104K CAP C .1UF-K-16V / CT-27L8SG CT-27C8G C2209 ECJ2VB1C104K CAP C .1UF-K-16V CT-27G8G CT-27G8UG CT-27L8G CT-27L8UG C2209 TCJ2VB1C104K CAP C .1UF-K-16V / CT-27L8SG CT-27C8G C2210 ECJ2VB1C104K CAP C .1UF-K-16V CT-27G8G / CT-27G8UG CT-27L8G CT-27L8UG...
  • Page 44 MAZ31100ML DIODE ZENER FUSES F801 XBA2A00101 FUSE 6.3A 125V INTEGRATED CIRCUITS IC001 MN101E03GTB3 IC002 TVR2AJ165S EEPROM / CT-27G8G CT-27G8UG IC002 TVR2AJ166S EEPROM / CT-27L8G CT-27L8UG CT-27L8SG / CT-27C8G IC003 GP1UE282GK IR SENSOR IC004 PST9128NR RESET IC005 PQ3RD13 3.3V STBY REGULATOR...
  • Page 45 L805 EXCELDR35V FERRITE BEAD L806 EXCELDR35V FERRITE BEAD L807 EXCELSA35V FERRITE BEAD L808 EXCELSA35V FERRITE BEAD L2301 EXCELDR35V FERRITE BEAD / CT-27L8G CT-27L8UG CT-27L8SG CT-27C8G L2301 EXCELSA35V FERRITE BEAD L2305 EXCELSA35V FERRITE BEAD TRANSISTORS Q001 2SD601ARTX TRANSISTOR Q070 2SD601ARTX TRANSISTOR...
  • Page 46 Ref. No. Part No. Part Name & Description Remarks Q357 2SD601ARTX TRANSISTOR Q358 2SD601ARTX TRANSISTOR Q359 2SD601ARTX TRANSISTOR Q360 2SB709ARTX TRANSISTOR Q361 2SB709ARTX TRANSISTOR Q362 2SB709ARTX TRANSISTOR Q411 2SB0710AQL TRANSISTOR Q412 2SD0602AQL TRANSISTOR Q451 2SB709ARTX TRANSISTOR Q501 2SC4212HLB TRANSISTOR Q551 2SC5902000LK TRANSISTOR Q560...
  • Page 47 Ref. No. Part No. Part Name & Description Remarks R041 ERJ6GEYJ222V RES M 2.2K-J-1/10W R042 ERJ6GEYJ222V RES M 2.2K-J-1/10W R043 ERJ6GEYJ153V RES M 15K-J-1/10W R044 ERJ6GEYJ101V RES M 100-J-1/10W R045 ERDS2TJ101T RES C 100-J-1/4W R046 ERJ6GEYJ102V RES M 1K-J-1/10W R047 ERJ6GEYJ472V RES M 4.7K-J-1/10W R048...
  • Page 48 Ref. No. Part No. Part Name & Description Remarks R372 ERJ6GEYJ101V RES M 100-J-1/10W R373 ERJ6GEYJ101V RES M 100-J-1/10W R374 ERJ6GEYJ102V RES M 1K-J-1/10W R375 ERJ6GEYJ102V RES M 1K-J-1/10W R376 ERJ6GEYJ102V RES M 1K-J-1/10W R377 ERJ6ENF3300V RES M 330-F-1/10W R378 ERJ6ENF3300V RES M 330-F-1/10W R379...
  • Page 49 Ref. No. Part No. Part Name & Description Remarks R552 ERDS1FJ1R0T RES C 1.0-J-1/2W R557 ERJ6GEYJ103V RES M 10K-J-1/10W R558 ERQ1CKPR56S RES F .56-K-1W R559 ERG2FJ683H RES M 12K-J-2W R561 ERG2FJ102H RES M 1K-J-2W R562 ERG2FJ270H RES M 27-J-2W R563 ERG3FJ150H RES M 15-J-3W R564...
  • Page 50 Ref. No. Part No. Part Name & Description Remarks R2357 ERJ6GEYJ472V RES M 4.7K-J-1/10W R2362 ERJ6GEYJ221V RES M 220-J-1/10W R2364 ERJ6ENF1001V RES M 1K-F-1/10W R2370 ERJ6GEYJ222V RES M 2.2K-J-1/10W R3002 ERJ6GEYJ221V RES M 220-J-1/10W R3003 ERJ6GEYJ221V RES M 220-J-1/10W R3004 ERDS2TJ101T RES C 100-J-1/4W R3005...
  • Page 51 7-KEY BUTTON (GRAY) / CT-27L8G CT-27L8UG CT-27L8SG TBX2AA1701GS 7-KEY BUTTON / CT-27G8G CT-27G8UG TBX2AA2602 7-KEY BUTTON / CT-27C8G JK3001 TJB2AA0221 REAR A/V JACK / CT-27L8G CT-27L8UG CT-27L8SG CT-27C8G JK3001 TJB2A9064B REAR A/V JACK / CT-27G8G CT-27G8UG JK3002 TJB2AA0046 FRONT A/V JACK...
  • Page 52 CT-27C8G / CT-27G8G / CT-27G8UG / CT-27L8G / CT-27L8UG / CT-27L8SG A-BOARD 1 of 4 TNP2AH047GA/GB...
  • Page 53 CT-27C8G / CT-27G8G / CT-27G8UG / CT-27L8G / CT-27L8UG / CT-27L8SG A-BOARD 2 of 4 TNP2AH047GA/GB...
  • Page 54 CT-27C8G / CT-27G8G / CT-27G8UG / CT-27L8G / CT-27L8UG / CT-27L8SG A-BOARD 3 of 4 TNP2AH047GA/GB...
  • Page 55 CT-27C8G / CT-27G8G / CT-27G8UG / CT-27L8G / CT-27L8UG / CT-27L8SG A-BOARD 4 of 4 TNP2AH047GA/GB...
  • Page 56 ..1.70 ..3.30 ..0.40 ..0.00 ..0.40 ..3.30 CT-27C8G / CT-27G8G / CT-27G8UG / CT-27L8G / CT-27L8UG / CT-27L8SG...
  • Page 57 0.00 0.00 Q820 Q830 Q831 130.40 129.80 0.60 0.00 130.40 0.20 130.80 130.50 0.00 C - BOARD Q351 Q352 Q353 3.90 3.80 4.00 163.00 165.30 160.20 3.60 3.60 3.70 CT-27C8G / CT-27G8G / CT-27G8UG / CT-27L8G / CT-27L8UG / CT-27L8SG...

  • Page 58: Audio Signal Path Block Diagram

    JK3001 REAR L&R Mixed AUDIO *(1) MPX IN IC2201 R-OUT L-OUT JK3001 REAR AUDIO *(2) R-IN L-IN IC2301 JK3002 AUDIO AMP FRONT AUDIO R-OUT L-OUT MUTE ON/OFF IC001 CT-27G8G / CT-27G8UG *(1) CT-27C8G / CT-27L8G / CT-27L8UG / CT-27L8SG *(2)
  • Page 59 CT-27C8G / CT-27G8G / CT-27G8UG / CT-27L8G / CT-27L8UG / CT-27L8SG A-BOARD 1 of 2 TNP2AH047...
  • Page 60 CT-27C8G / CT-27G8G / CT-27G8UG / CT-27L8G / CT-27L8UG / CT-27L8SG A-BOARD 2 of 2 TNP2AH047 C-BOARD TNP2AA122...

  • Page 61: Video Signal Path Block Diagram

    VIDEO *(1) R OUT G OUT B OUT MSCIN JK3002 FRONT VIDEO Q360 Q361 Q362 JK3003 S-Video Q357 Q358 Q359 A-BOARD Q354 Q355 Q356 Q351 Q352 Q353 C-BOARD CT-27G8G / CT-27G8UG *(1) CT-27C8G / CT-27L8G / CT-27L8UG / CT-27L8SG *(2)
  • Page 62 IC451 PIN 3 (PUMP UP) IC501 PIN 4 (H-DRIVE) A12 PIN 2 (HEATER) 1.29 kVp-p 398 Vp-p 2.92 Vp-p 121 Vp-p Q551 Collector (H OUT) IC801 PIN 1 IC801 PIN 7 Q501 Collector CT-27C8G / CT-27G8G / CT-27G8UG / CT-27L8G / CT-27L8UG / CT-27L8SG...

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