V-Com Adjustment (Pk-59 Board) - Sony MVC-FD75 Service Manual

7. V-COM Adjustment (PK-59 Board)

This adjustment corrects the DC bias of common electrode drive
signals of the LCD panel. If shifted, the LCD screen will be coarse,
or flicker, or vertical streaks will appear.
Mode
Signal
Measurement Point
Measuring Instrument
Adjustment Page
Adjustment Address
Specified Value
Note: "Contrast Adjustment" and "Bright Adjustment" must be
already finished.
Adjusting method:
Order Page Address Data
1 0 01 01
2 3 02 01
3 3 18 10
4 F 37
5 F 37
Processing after Completing Adjustment:
Order Page Address Data
1 3 18 00
2 3 02 00
3 0 01 00
B
A
B
A
Fig. 5-1-19
PLAY
Alignment disk: 50% white
signal
Check on the LCD screen
F
37
The brightness difference
between the section A and B is
minimum.
Procedure
Press PAUSE button.
Change the data so that the
brightness of the section A
and section B is equal.
Press PAUSE button.
Procedure
Press PAUSE button.
A
B
A
B
8. White Blance Adjustment (PK-59 Board)
This adjustment corrects the white balance.
If disordered, the colors on the LCD screen will not be reproduced.
correctly.
Mode
Signal
Measurement Point
Measuring Instrument
Adjustment Page
Adjustment Address
Specified Value
Note: 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:
Order Page Address Data
1 0 01
2 3 02
3 3 17
4 3 18
5 F E0
6 F 33
34
7 F 33
34
Processing after Completing Adjustment:
Order Page Address Data
1 F E0
2 3 17
3 3 02
4 0 01
5-20
PLAY
Alignment disk: 50% white
signal (with burst)
Check on the LCD screen
F
33, 34
LCD screen must not be colored
Procedure
01
01
01 Press PAUSE button.
00 Press PAUSE button.
15 Press PAUSE button.
Change the data and so that
the LCD screen is not
colored.
Press PAUSE button.
Procedure
1B Press PAUSE button.
00 Press PAUSE button.
00
00