Adjustment Procedure - Panasonic TX-21GV1C Serviceanleitung

ADJUSTMENT PROCEDURE

Item / Preparation
Sub Tuner AFT
1) Set a signal generator with
-RF FREQUENCY = 38,9MHz
-RF OUTPUT LEVEL = 80±5dBuV.
2) Connect a signal generator RF output to TP2 (TUNER IF
OUTPUT). Ensure there is no signal input to the
TUNER.
3) Connect the DC voltage meter to TP3.
Main Tuner AGC
1) Set a pattern generator with RF level 60 ± 2dBuV,
210,25MHz.
2) Connect an oscilloscope to P101 (Tuner AGC Input).
Sub Tuner AGC
1) Set a pattern generator with RF level 60 ± 2dBuV,
210,25MHz.
2) Connect an oscilloscope to P101 (Tuner AGC Input).
Screen
1) Apply a Colour Bar Pattern signal.
2) Connect an oscilloscope to P906 (CRT Cathode RGB).
3) Press the SCREEN key.
Focus
1) Apply a RETMA Pattern signal.
White Balance
1) Apply a Colour Bar Pattern signal.
X-Position Adjustment, P2 and P3
1) Play DP-2 Test tape (Colour bar, Audio 6KHz).
2) Enter Service Mode using Service Remote and
deactivate Auto-Tracking by pressing ATK-OFF key.
3) Set oscilloscope to CHOP mode and connect CH1 to
VIDEO HEAD SW (PYO4 pin 6). Connect CH2 to the
PB ENVE (PYO4 pin 4) and trigger CH1.
Azimuth Adjustment
1) Connect an oscilloscope to the AUDIO OUTPUT
terminal (P601).
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Adjustments
Adjust L201 (AFT COIL) for 2,2V ± 0,1V.
Adjust using "AGC UP/DOWN" key until the voltage drops to
1,0Vdc ±0,2Vdc below its maximum voltage.
Press the "SUB AGC" key in Service mode and monitor the
SUB TUNER picture whilst adjusting R202 (SUB AGC VR) to
1,0Vdc ±0,2Vdc below its maximum voltage.
Adjust the screen volume on the FBT so that the highest
black level voltage is 130V ± 5Vdc {150V ± 5Vdc}.
Adjust FOCUS VOLUME on the FBT for optimum setting.
Adjust the RGB UP/DOWN key to obtain optimum
WHITE BALANCE.
Adjust, with the corn screw, until both TRK MAX and
TRK MIN have the same size of envelope.
Adjust P2, P3 so that both the beginning and the end of the
envelope waveform are flat.
After test tape playback, adjust the output level, using the
outer screw of the A/C head to obtain maximum waveform.
(6KHz -3,8dBm +1dBm / -3dBm).
Fix the azimuth screw with locking paint.
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