1- Vif Detector Output Level Confirmation; 3- Buzzing Confirmation (Audio Circuit); 4- Anode And Heater Voltage Confirmation - Panasonic TC-20KL04A Service Manual

TC-20KL04A / TC-20KL04P / TC-29KL04A / TC-29KL04P
ADJUSTMENTS
ITEM / PREPARATION
1- RF AGC ADJUSTMENT
1. Supply a color bar pattern and adjust the RF input signal
of 69 dB µV (75Ω opened channel 07 RF freq.: 175.25
MHz).
2. Connect the digital multimeter in TPA15.
2- VIF DETECTOR OUTPUT LEVEL
CONFIRMATION
3- BUZZING CONFIRMATION
(AUDIO CIRCUIT)
1. Connect the oscilloscope with a 7kHz filter between A22-
2 and A22-3 speakers terminals .
2. Adjust the sound to maximum.
3. Adjust AVL: OFF

4- ANODE AND HEATER VOLTAGE CONFIRMATION

1. Supply a crosshatch signal.
2. Adjust the current beam to zero. (0 beam).
3. Adjust "SCREEN VR" and "CONTRAST" to minimum.
Nota:
(When using a high voltage meter resistive type, it is
necessary to use an electrostatic meter type to verify the
values)
PROCEDURE
ADJUSTMENT:
1. Select "RF AGC" on "CHK2" service mode.
2. Adjust "RF AGC" by pressing VOL(+) or (-) until obtaining
2.2±0.1V in TPA15.
3. Increase the input level by +2 dB and confirm that the
voltage decreases in TPA15.
CONFIRMATION:
1. Install the chassis in the VIF calibration JIG and tune in a
63 dBU colorbar pattern (75Ω opened).
2. Connect the oscilloscope in TPA31.
3. Confirm that the output video sign is 1.05 ± 0.15 Vp-p in
TPA 31.
CONFIRMATION:
1. Supply a colorbar signal with local frequency adjusted
and the AFC ON (Channel with sound bearer and without
modulation).
2. Assure that the width in the buzzing waveform is smaller
than 500 m Vp-p.
CONFIRMATION
1. Connect a voltage meter between TPA10 and ground.
Confirm that the voltage +B is within a range of 140.5V±
1.5V
2. Connect a high frequency voltage meter (VRMS) among
the heater, and confirm that the voltage is as below:
20" PHILIPS A48EAK01X
20" SAMSUNG A48KRD89X
29" PHILIPS A68AJB82X
3. Connect the high voltage meter in the CRT anode pin,
and confirm that the high voltage is within
CRT
29"
20"
- 12 -
smaller than
500 m Vp-p
6,15 ± 0,25 Vrms
6,30 ± 0,24 Vrms
6,30 ± 0,24 Vrms
range.
[A]
[A]
30,5 ~ 27,6
27,2 ~ 25,0