Electrical Adjustments; Monitor Section - Sony XTL-750W Service Manual

MONITOR SECTION

Equipment Used
The measuring equipment below are used for these electrical
adjustments:
• Oscilloscope
• NTSC pattern generator
• Regulated DC power supply
• Digital voltmeter
Connection of Equipment
Unless otherwise specified, the measuring equipment should be
connected as shown below:
INPUT (1)
MONITOR OUT
(VIDEO)
NTSC pattern
Tuner unit
generator
XT-991V/992V
VIDEO OUT
(75 Ω )
Parking
Setup for Adjustment
The adjustment signal is a 5-step gray scale signal from a NTSC
pattern generator.
Input the gray scale signal into the tuner unit and connect an oscil-
loscope to TP14 on the MONITOR MAIN board. Check that the
width between the black and white levels of the gray scale signal is
0.74 Vp-p.
DC/DC Converter Voltage Adjustment
Procedure:
1. Display the gray scale on the monitor screen.
2. Connect a digital voltmeter to TP57 on the MONITOR MAIN
board.
3. Adjust RV401 so that the reading on the digital voltmeter is
5.35 ± 0.05 V.
Adjustment Location: See page 11.
SECTION 3

ELECTRICAL ADJUSTMENTS

Monitor
XVM-750W
Regulated DC
power supply
ACC cord
+
–
white
0.74Vp-p
black
Inverter Voltage Adjustment
Procedure:
1. Display the gray scale on the monitor screen.
2. Connect a digital voltmeter to TP64 on the MONITOR MAIN
board.
3. Adjust RV601 so that the reading on the digital voltmeter is
7.80 ± 0.05 V.
Adjustment Location: See page 11.
Bright Adjustment
Procedure:
1. Display the gray scale on the monitor screen.
2. Connect a digital voltmeter to TP70 on the MONITOR MAIN
board.
3. Adjust RV201 so that the reading on the digital voltmeter is
2.13 ± 0.02 V.
Adjustment Location: See page 11.
VCOM Adjustment (1)
Procedure:
1. Display the gray scale on the monitor screen.
2. Connect an oscilloscope to TP102 on the MONITOR MAIN
board.
3. Adjust RV210 so that the amplitude of the output waveform is
7.5 ± 0.1 Vp-p.
4. Adjust RV211 so that the level A of the output waveform is at
5.5 ± 0.05V DC.
Adjustment Location: See page 11.
RGB Amplitude Adjustment
Procedure:
1. Display the gray scale on the monitor screen.
2. Connect a digital voltmeter to TP63 on the MONITOR MAIN
board.
3. Adjust RV208 so that the reading on the digital voltmeter is
2.37 ± 0.02 V.
Adjustment Location: See page 11.
γ 2 Adjustment
Procedure:
1. Display the gray scale on the monitor screen.
2. Connect a digital voltmeter to TP67 on the MONITOR MAIN
board.
3. Adjust RV213 so that the reading on the digital voltmeter is
2.19 ± 0.02 V.
Adjustment Location: See page 11.
– 9 –
A
7.5Vp-p
0V