Panasonic TC-21FG20M-MALAYSIA, Service Manual

Page: 7 / 30

2.5.1. +B Voltage
Item / preparation
1. Operate the TV set.
2. Set control as follows :
Brightness ........... minimum
Contrast ............... minimum
Adjustment procedure
1. Confirm the DC voltage at the indicated test points, as
follows :
TPA 10 : 141.0 ± 1.5V
TPA 8 : 8 ± 1V
TPA 9 : 5 ± 1V
TPA 21 : 175 ± 15V
2.5.2. RF AGC
Item / preparation
1. Receive a colour bar signal at an RF level of 69 ± 1-2 dBU
with 75
Ω
loaded.
2. Connect digital multimeter to RF AGC at Tuner.
Adjustment procedure
1. Select “RF AGC” indication in CHK2, on Screen by remote
control at factory mode.
2. Set RF AGC by using remote control Volume (+) or Volume
(-) button until voltage AGC at Tuner reaches 2.3 ± 0.1V at
TPA 15 (Tuner point).
3. Increase RF signal strength by 2dB, confirm AGC at Tuner
voltage drop.
2.5.3. High Voltage
Item / preparation
1. Receive the crosshatch pattern.
2. Set to 0 Beam.
Screen VR .......... minimum
Contrast .............. minimum
Adjustment procedure
1. Connect a DC voltage meter to TPA 10 and confirm the +B
voltage is 141.0 ± 1.5V.
2. Connect a high frequency voltmeter to heater and confirm
that voltage reads 6.3 ± 0.24 (VRMS).
3. Normalize the brightness and contrast.
2.5.4. NTSC TINT COLOUR
Item / preparation
1. Connect oscilloscope probe to TPL1 (R OUT) with 10k
Ω
series resistor.
2. Press Main Menu and set system to use AV-NTSC (3.58
MHz).
DYNAMIC ................... Normal
Channel CLR Set ..... STD
Adjustment procedure
1. Adjust Sub-Tint so that No. 2, 3 and 4 becomes level
waveform is similar to Fig. 3.
2. Confirm phase at Tint is changes more than ± 15 by Tint
control.
3. Confirm that colour level is maximum when colour DAC is
adjusted to maximum position.
Note: Use remote control only when adjusting user mode to
Sub-Tint.
2.5. Adjustment Procedure
7
TC-21FG20M-MALAYSIA