Sony XTL-W70 Service Manual page 11

VCOM Amplitude Adjustment
Procedure:
1. Press the TV/VIDEO button (S106) to the VIDEO mode,
display the gray scale screen on the monitor screen.
2. Connect an oscilloscope to TP401 on the MONITOR board.
3. Adjust RV411 so that the level A of the output waveform is
6.88 ± 0.02 Vp-p.
Adjustment Location: See page 12.
VCOM Bias Adjustment
Procedure:
1. Press the TV/VIDEO button (S106) to the VIDEO mode,
display the gray scale on the monitor screen.
2. Connect an oscilloscope to TP401 on the MONITOR board.
3. Adjust RV412 so that the waveforms A and B meet the
specified value.
specified value A: 5.20 ± 0.04 V
B: -1.68 ± 0.04 V
Adjustment Location: See page 12.
Freerun Frequency Adjustment
Procedure:
1. Set the input signal with no signal.
2. Press the TV/VIDEO button (S106) to the VIDEO mode.
3. Connect a frequency counter to TP16 on the MONITOR board.
4. Adjust RV902 so that the reading on the frequency counter is
15.37 ± 0.02 kHz.
Adjustment Location: See page 12.
H CEN Adjustment
Procedure:
1. Input the mono scope signal from a NTSC pattern generator.
2. Press the TV/VIDEO button (S106) to the VIDEO mode,
display the mono scope on the monitor screen.
A
3. Adjust RV901 so that the mono scope is displayed in
symmetrical pattern on the monitor screen.
Adjustment Location: See page 12.
A
0V
B
XTL-W70
11