Panasonic TC-29G12P service manual Electrical Inspections, Deflection Circuit PRE-ADJUSTEMENTS

Service Adjustments and Calibrations TC-20G12P / TC-29G12P / TC-29G12PU

ELECTRICAL INSPECTIONS

REQUIRED EQUIPMENTS / CONNECTIONS:

Voltmeter 150VDC: between C809 (+) and Ground HOT(-).

RMS Voltmeter: CRT Heater Terminal.

PROCEDURE:

1.Apply a PHILIPS pattern.

2.Adjust AC supply to 110 or 220 V. Adjust BRIGHT and CONTRAST control until get a totally black screen. The DC Voltmeter must be 130V±2.5V.

3.The heater terminal voltage must be: TC-20G12P→6,15V+0.40Vrms _0.24Vrms TC-29G12P/TC-29G12PU→6,3V+0.40Vrms _0.24Vrms

DEFLECTION CIRCUIT PRE-ADJUSTEMENTS

REQUIRED EQUIPMENTS / CONNECTIONS: Voltmeter (50KV): Connect between CRT anode and CRT DAG GROUND.

PROCEDURE:

1.Apply a PHILIPS pattern.

2.Adjust VERTICAL HEIGHT (DAC B:5) until get a circle.

3.Apply a CROSSHATCH pattern.

4.Adjust BRIGHT and CONTRAST control until get a totally black screen. The voltage on Voltmeter must be:

TC-20G12P→26,25kV±1,25kV TC-29G12P/TC-29G12PU→29,1kV+1.4kV_1.5kV

5.Apply a PHILIPS pattern and readjust the BRIGHT and CONTRAST control to get a correct image picture.

6.Adjust the HORIZONTAL CENTER (“Cc” register) until the image is correctly centered.

To TC-29G12P and TC-29G12PU only:

7.Confirm that the horizontal width is in normal range.

8.Correct E-W Pincushion by adjusting R761 in the Z-PCB.

9.Correct the horizontal width by adjusting R760 in the Z-PCB.

AGC CIRCUIT PRE-ADJUSTMENTS

REQUIRED EQUIPMENTS / CONNECTIONS:

Oscilloscope: TP2.

PROCEDURE:

1.Apply a 63dB±2dB pattern signal (75Ω open) (Using a high VHF channel 7 ~ 13).

2.Set the CONTRAST control on center position.

3.Verify the CONTRAST variation with SUB-CONTRAST (DAC B:3) to get a 3.0Vp-p wave form on the oscilloscope at TP2.

3Vp-p

Excluding the eraser part

WHITE BALANCE ADJUSTMENTS

REQUIRED EQUIPMENTS / CONNECTIONS: Oscilloscope: Connect to CRT board “GK” and ground.

PREPARATION:

1.Get turn ON the equipment for about 15 minutes.

2.Set standard WHITE BALANCE.

3.Adjust the image mode to “DYNAMIC”.

4.Fix the COLOR adjust in “NORMAL”.

5.Fix the CONTRAST adjust in “NORMAL”.

6.Enter in the service mode.

7.Adjust CUT OFF and DRIVE DATA to:

C0: CUT OFF_R= 0_64

C1: CUT OFF_G= 0_128

C2: CUT OFF_B= 0_64

C3: DRIVER_R= 64

C4: DRIVER_B= 64

8.Adjust SCREEN VR to minimum.

9.Connect the oscilloscope.

PROCEDURE:

1.In Service Mode, press “R-TUNE” on remote control to enter in the Horizontal Line mode.

2.Look (GK) on the oscilloscope, then adjust SUB-BRIGHT (DAC:B2) until the raster period be as the draw bellow.

GK waveform

TC-20G12P = 160VDC

TC-29G12P = 195VDC

TC-29G12PU = 195VDC

3.Adjust SCREEN VR to the first line stayed lightly illuminated.

Note: After adjust, the SCREEN VR doesn’t must be moved.

4.Adjust CUTT OFF to the horizontal line become white. (R,B CUT OFF) (DAC: C0) (DAC: C2).

5.Press again “R-TUNE” to exit of Horizontal Line mode.

6.Get appropriate White Balance moving the REC drive (DAC: C3) and BLUE drive (DAC: C4).

7.Apply a PHILIPS pattern.

8.Get a normal image adjusting CONTRAST, BRIGHT and FOCUS VOLUME controls. Then confirm the image doesn’t show serious convergence loss.

4.Verify if snow appear when the RF AGC register (DAC:Ca) is decreased. Then increase it slowly until the snow has disappeared.

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