Panasonic TC-20B12, TC-14A12P service manual Ntsc Sub-Tint Calibration, White Quality Calibration

TC-14A12P / TC-20B12

Service Adjustments and Calibrations

NTSC SUB-TINT CALIBRATION WHITE QUALITY CALIBRATION

1. PREPARATION:

1.1.Connect the oscilloscope to TPL1 (R OUT) in serie with a 10KΩ resistor.

1.2.Receive a rainbow pattern through VIDEO IN.

1.3.Adjust “IMAGE” to DYNAMIC NORMAL.

1.4.Adjust “COLOR FOR CHANNEL” to NORMAL.

1.5.Set the CHK2 service mode option, press “5” on the remote control unit and confirm that OSD becomes blue (AKB turned off).

1.6.Connect a short circuit jumper between TPA10 and TPA20.

2. CALIBRATION:

2.1.Adjust [C] for 5.0±0.2V through the BRIGHT control variation according to fig. 1.

2.2.Adjust the NTSC SUB-TINT level according to fig. 1 positions 2, 3 and 4.

2.3.Remove the jumper , press “5” and confirm that OSD becomes white (AKB turned on).

1 2 3 4 5 6 7 8 9 10

1. PREPARATION:

1.1.Adjust the HELMHOLTZ device to local magnetic field. Hori- zontal: 0 ± 0.003 X 10-4T

1.2.Receive a white purity pattern.

1.3.Adjust CONTRAST and BRIGHT controls to maximum.

1.4.Previously adjust the CONVERGENCE.

1.5.Fully degauss the CRT by using an external degaussing coil.

2. CALIBRATION:

2.1.Adjust the magnetic field in 0.4x10-4T (400 mG), and check the white quality with the CRT turned to EAST and to WEST.

2.2.Receive a red pattern, adjust the COLOR control to maximum and confirm the purity adjustment.

2.3.If purity error is found at the CRT corners, to apply magnetic tapes to correct it, fully degauss the CRT again and repeat the steps 1 and 2. Don't use this magnetic tapes on the internal side of the yoke.

2.4.Receive a white purity pattern, adjust the COLOR control to maximum and confirm the purity adjustment.

C

0V

Fig. 1

C

B

2 3 4 A:B = 1:2

Fig. 2

VERTICAL DEFLECTION

CALIBRATION AND CONFIRMATION

1. PREPARATION:

1.1.Adjust the HELMHOLTZ device to the local magnetic field

1.2.Adjust IMAGE to DYNAMIC NORMAL.

2.CONFIRMATION AND CALIBRATION S-CORR :

• CONFIRMATION IN 50HZ

2.1.Receive a PAL-N Philips pattern

2.2.Confirm that S-CORR 50Hz is in [18] DAC.

• CONFIRMATION IN 60HZ

2.3.Receive a monoscope pattern.

2.4.Confirm that S-CORR 60Hz is in [18] DAC.

• V-SLOPE CALIBRATION

2.5.Receive a monoscope pattern.

2.6.Adjust V_SLOPE so that the beginning of the black part of the image be aligned with the center of the CRT as below.

PROTECTION CIRCUIT (SHUTDOWN)

CONFIRMATION OF OPERATION

1. PREPARATION:

1.1.Receive a crosshatch pattern.

1.2.Adjust CONTRAST and BRIGHT controls to minimum.

2. CONFIRMATION:

2.1.Connect the voltmeter in TPA22 and confirm that the voltage is smaller than [A].

2.2.Connect a DC source in TPA22 and confirm that the protection circuit doesn't act when the voltage is [B].

2.3.Confirm that the protection circuit acts with smaller voltage than [C].

Condition	14 inches	20 inches
A	19,67V	21,18V
B	20,66V	22,31V
C	22,49V	24,37V

CRT

CENTER

3.VERTICAL CENTRALIZATION 50 HZ CALIBRATION

3.1.Receive a PAL-N Philips pattern

3.2 Adjust V-SHIFT 50Hz so that Philips pattern’s center it is in the CRT center.

4.VERTICAL CENTRALIZATION 60 HZ CALIBRATION

4.1.Receive a monoscope pattern.

4.2.Adjust V-SHIFT 60Hz so that the monoscope pattern’s it is in the CRT center

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