V-Com Adjustment (Pk-45 Board); White Balance Adjustment (Pk-45 Board) - Sony MVC-FD91 Service Manual

8. V-COM Adjustment (PK-45 board)

Set the DC bias of the common electrode drive signal of LCD to the
specified value.
If deviated, the LCD display will move, producing flicker and
conspicuous vertical lines.
Mode Playback
Signal No signal
Measurement Point Check on LCD screen
Measuring Instrument
Adjustment Page F
Adjustment Address 36
Specified Value The brightness difference between the
section A and section B is minimum.
Note 1: Perform "Bright Adjustment" and "Contrast Adjustment" before
this adjustment.
Adjusting method:
1) Select page: 0, address: 01, and set data: 01.
2) Select page: 3, address: 02, and set data: 01.
3) Select page: 3, address: 18, and set data: 01.
4) Select page: 3, address: 19, and set data: 10.
5) Select page: F, address: 36, change the data so that the
brightness of the section A and that of the section B is equal.
6) Press the PAUSE button of the adjustment remote commander.
7) Select page: 3, address: 02, and set data: 00.
8) Select page: 3, address: 18, and set data: 00.
9) Select page: 3, address: 19, and set data: 00.
10) Select page: 0, address: 01, and set data: 00.
B
A
B
A
Fig. 5-1-25.
A
B
A
B

9. White Balance Adjustment (PK-45 board)

Correct the white balance.
If deviated, the LCD screen color cannot be reproduced.
Mode
Signal
Measurement Point
Measuring Instrument
Adjustment Page
Adjustment Address
Specified Value
Note 1: Check the white balance only when replacing the following parts.
If necessary, adjust them.
1. LCD panel
2. Light induction plate
3. IC802
Adjusting method:
1) Select page: 0, address: 01, and set data: 01.
2) Select page: 3, address: 02, and set data: 01.
3) Select page: 3, address: 18, and set data: 01.
4) Select page: 3, address: 19, and set data: 00.
5) Select page: F, address: 32 and 33, set the data to the initial
value.
Note: Press the PAUSE button of the adjustment remote commander
each time to set the data.
Address
32
Data
77
6) Check that the LCD screen is not colored. If colored, change
the data of page: F, address: 32 and 33 so that the LCD screen
is not colored.
Note: To write in the non-volatile memory (EEPROM), press the
PAUSE button of the adjustment remote commander each time
to set the data.
7) Select page: 3, address: 02, and set data: 00.
8) Select page: 3, address: 18, and set data: 00.
9) Select page: 0, address: 01, and set data: 00.
5-28
Playback
No signal
Check on LCD screen
F
32, 33
The LCD screen should not be
colored.
33
7A