Contrast Y Level Adjustment; Contrast Level Adjustment - Sony CCU-700A Maintenance Manual

3-3. Video Signal System Adjustment

3-3-15. CONTRAST Y Level Adjustment

Rank: B
Equipment:
Oscilloscope, Waveform monitor
To be extended:
VA-156 board
Preparation
1. BARS button/MSU-700 → "OFF"
2. S126 (TEST ON/OFF)/VA-156 board → "ON"
3. CONTRAST ON/OFF button/MSU-700 → "OFF"
Test point:
VBS 1 OUT connector/CCU rear panel
Adjusting point: 1RV341 (CONTRAST Y)/
[For NTSC] A = 100 ±2 IRE
Specification:
[For PAL]
3-12
(75 Z terminated)
VA-156 board
A = 700 ±10 mV
A

3-3-16. Contrast Level Adjustment

Rank: B
Equipment:
Waveform monitor
To be extended:
VA-156 board
Preparation
• BARS button/MSU-700 → "OFF"
• TEST 1 button/MSU-700 → "ON"
• S126 (TEST ON/OFF)/VA-156 board → "ON"
• Set the CONTRAST adjustment value that is displayed
on the display block to "99" with control knob.
Test point: VBS 1 OUT connector/CCU rear
panel
Adjusting point: 1RV342 (GAMMA LEVEL)/VA-
156 board
Adjustment Procedure
• Adjust 1RV342 (GAMMA LEVEL)/VA-156 board so
that the signal level at VBS 1 OUT connector/CCU rear
panel is not fluctuated even if CONTRAST button/
MSU-700 is turned ON or OFF.
Note:
After the adjustment, re-check
"3-3-15. CONTRST Y Level
Adjustment" .
Make sure not to fluctuate.
CCU-700A
CCU-700AP