Equipment Used; Connection Of Equipment; Adjustment; Frequency Adjustment - Sony XVM-R75 Service Manual

XVM-R75
When measuring, the ground should be connected to the ground (pin 15 of connector B1) in the display board unless otherwise specified.

1-1. EQUIPMENT USED

The following measuring equipment are used for these electrical adjustments:
• Oscilloscope
• NTSC pattern generator
• Stabilized power supply
• Digital voltmeter
• Frequency counter
• Connection box (XA-117)

1-2. CONNECTION OF EQUIPMENT

pattern generator
VIDEO IN
VIDEO
1-3. 5V ADJUSTMENT
1. Display gray scale on the monitor screen.
2. Connect digital voltmeter to the C10 position of L19.
3. Adjust VR1 so that the reading on the voltmeter stands at the specified value.
Specified value: 5.00 ± 0.05 V

1-4. FREQUENCY ADJUSTMENT

This frequency adjustment on the DC-DC converter is only performed if there is switching noise mixed on the screen.
Adjust RV20 to a position in which no noise appears on the screen.

1-5. PLL FREE RUN FREQUENCY ADJUSTMENT

1. Make the input signal no signal.
2. Connect frequency counter to pin th of IC U705.
3. Adjust the semi-fixed resistor VFRER until the frequency is at 15895 ± 20 Hz.
2
connection box
XA-117
G
N
D B+
stabilized
power supply
14.4V
monitor
XVM-R75