Adjustment Procedure; Voltage; Rf Agc; Eht & Heater - Panasonic TC-21P50R Service Manual

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Adjustment Procedure

Item / Preparation
B Voltage
1. Operate the TV set.
2. Set controls :
Bright..................
Sub Bright...........
Volume................

RF AGC

1. By using spectrum & attenuator ensure
the RF signal input to the TV is 69dBU
9
(75
open).
2. Connect digital multimeter to TPA20.
EHT & HEATER
1. After H-WIDTH Rough Adjustment.
2. Receive the crosshatch pattern.
3. Set to 0 beam.
(screen VR :MIN. CONTRAST :MIN.)

SUB CONTRAST

1. Connect oscilloscope probe to TPA41 (G OUT).
2. Receive the PAL colour bar pattern, and
adjust local frequency at the best tuned
position.
3. Connect short-jumper to TPA57 and
TPA50.
4. Connect short-jumper to FBT pin3 and
TPA32.
5. Picture menu : DYNAMIC NORMAL.
AI
: OFF
Channel colour SET....STD.
6. Set to 2.3 ± 0.2V by BRIGHT.
PAL COLOUR OUTPUT
1. Receive the PAL colour bar pattern, and
adjust local frequency at the best tuned
position.
2. Connect short-jumper to TPA57 and
TPA50.
3. Connect short-jumper to FBT pin3 and
TPA32.
4. Picture menu : DYNAMIC NORMAL.
AI
: OFF
Channel colour SET....STD.
5. Set to 2.3 ± 0.2V by BRIGHT.
1. Confirm that the indicated test points for the specified voltage:
TPA140 : 115.0 ±
TPA05 :
minimum
TPA32 :
minimum
TPA220 : 21.5 ±
minimum
1. Select "RF AGC" indication in CHK2. ON Screen by remote control
at factory mode.
2. Set RF AGC by control volume (-) or (+) at voltage TPA 20 reach
2.6 ± 0.3V.
3. Increase RF signal strength by 2dB. Confirm TPA20 voltage drop.
1. Connect DC voltage meter to D831 Cathode and confirm that +B
voltage is 142.0 ± 2V.
2. Connect High frequency voltmeter to heater, and confirm that voltage
reads
3. Connect High voltage meter to CRT anode, and confirm that high
voltage is less than 28.5 (+0.7, -1.5)V .
1. Adjust Sub-Contrast, so that waveform is 2.5 ± 0.1Vp-p as shown.
1. Connect oscilloscope prebe to TPA41 (G OUT) and adjust SUB
COLOUR, so that waveform is 2.5 ± 0.1Vp-p as in Fig.1.
2. Connect oscilloscope prebe to TPA40 (R-OUT) and conform the
waveform is 3.2 ± 0.5Vp-p as in Fig.2.
Adjustment Procedure
2.0 V
5.0 ±
1.0V
5.0 ±
1.0V
1.5V
6.3 ± 0.24 (VRMS)
- 11 -
TPA12 : 12.0 ± 1.0 V
TPA09 :
9.0 ± 1.0V
2.5±0.1Vp-p
2.3±0.2V
0V
2.5±0.1Vp-p
2.3±0.2V
Fig.1
0V
3.2±0.5Vp-p
2.3±0.2
Fig.2

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