V-Com Level Adjustment (Pk-50 Board); V-Com Adjustment (Pk-50 Board) - Sony MVC-FD85 Service Manual

7. V-COM Level Adjustment (PK-50 board)

Set the common electrode drive signal level of LCD to the specified
value.
Mode PLAY
Signal Arbitrary
Measurement Point Pin 8 of CN803 of FC-72 board
(COM)
Measuring Instrument Oscilloscope
Adjustment Page D
Adjustment Address D6
Specified Value LCD TYPE SH: A = 6.50 ± 0.05V
LCD TYPE CA: A = 5.65 ± 0.05V
Note: Refer to "1-5-1. LCD type check" for the discrimination of the LCD
type.
Adjusting method:
1) Select page: 0, address: 01, and set data: 01.
2) Select page: D, address: D6, change the data and set the V-
COM signal level (A) to the specified value.
3) Press the PAUSE button of the adjustment remote commander.
4) Select page: 0, address: 01, and set data: 00.
2H
Fig. 5-1-20.

8. V-COM Adjustment (PK-50 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
Signal
Measurement Point
Measuring Instrument
Adjustment Page
Adjustment Address
Specified Value
Note: Perform "Bright Adjustment" and "Contrast Adjustment" before this
adjustment.
Adjusting method:
1) Select page: 0, address: 01, and set data: 01.
2) Select page: 5, address: F1, set data: 02.
3) Select page: 2, address: 10, set data: 02.
4) Select page: D, address: D8, change the data so that the
brightness of the section A and that of the section B is equal.
5) Press the PAUSE button of the adjustment remote commander.
6) Select page: 5, address: F1, set data: 00.
7) Select page: 2, address: 10, set data: 00.
8) Select page: 0, address: 01, and set data: 00.
A
5-31
PLAY
Arbitrary
Check on LCD display
D
D8
The brightness difference between the
section A and section B is minimum.
B A
A
B
B A
A B
Fig. 5-1-21.