21HT-15H
"SCREEN ADJUSTMENT
1. G2 Adjustment
1. Apply mains voltage of 220V ac / 50H z to TV.
3.0 ? 0.1 Vdc
2. Go into service mode (refer to ?How to access service mode? section).
CHCH
3. Use / buttons in order to select ?BLUE-BACK: 1?.
4. Use the volume down button () to deactivate the blue-back feature. ?BLUE-
BACK: 0? will appear on screen.
5. Re-start the TV set with the mains switch button () to store the adjustment
and exit service mode.
1V
6. Normalise the picture control settings (contrast, colour, brightnes s...)
7. Press TV/VIDEO button in order to select ?SCART ? (without video signal: black
screen).
8. Apply the oscilloscope test probe to the test point <TP851> (R0 Ved output of
IC801) to see the signal shown in Fig.4.
Fig.4
9. Adjust SCREEN VR (G2) to obtain 3 Vdc ? 0.1 Vdc.
10. Go into service mode (refer to ?How to access service mode? section).
CHCH
11. Use / buttons in order to select ?BLUE-BACK: 0?.
12. Use the volume up button () to deactivate the blue-back feature. ?BLUE-BACK: 1? will appear on screen.
13. Re-set the TV with the mains switch button () to store the adjustment and exit service mode.
2. Focus Adjustment
1. Apply mains voltage of 220V ac / 50Hz to TV.
2. Receive the ?MONOSCOPE ? pattern signal to a level between 60 and 80 dB?V.
3. Normalise the picture control settings (contrast, colour, brightness...)
4. Adjust focus potentiometer to obtain maximum definition.
" AGC ADJUSTMENT
1. Receive the ?COLOUR BAR ? signal (Channel E-OSCILLOSCOPE
Fig.5
12). Signal
Strength: 57 dB?V ? 1 dB ?V (50 ohm open) or 59 dB
?V ? 1 dB ?V (75 ohm open).
0.1V
2. Connect the oscilloscope to test point <TP201> (R201
TP201
lead) and the voltmeter c.c., as show n in Fig.5.
3. Go into service mode (refer to ?How to access service
mode? section).
4.5V
4. Use CH / CH buttons in order to select ?AGC ?.
5. Use / to obtain the Tuner output pin drop: 0.1 V ~ TV SET
0.3 V below maximum voltage.
6. Change the antenna input signal to 66-70dB ?VOV, and LTMETER
make sure there is no noise.
7. Turn up the input signal to 90-95 dB ?V to be sure that
there is no cross.
8. Re-set the TV with the mains switch button () to store the adjustment and exit service mode.
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