Center Voltage Adjustment (Pk-064 Board); V-Com Dc Adjustment (Pk-064 Board) - Sony Cyber-shot DSC-P71 Service Manual

DSC-P71/P71M

9. Center Voltage Adjustment (PK-064 Board)

Set the center level of VIDEO signal for driving the LCD to the
specified value.
Mode
Signal
Measurement Point
Measuring Instrument
Adjustment Page
Adjustment Address
Specified Value
Adjusting method:
Order Page Address Data
1 0 01
2 A 02
3 4 F1
4 A 8B
5 A 8B
Note: Adjust it between data 00 and 7F.
Processing after Completing Adjustments:
Order Page Address Data
1 A 02
2 4 F1
3 0 01
PLAY
Arbitrary
Pin 9 of CN903 (VG)
Digital voltmeter
A
8B
A = 7.00 ± 0.05 Vp-p
Procedure
01
03 Press PAUSE button
03
Change the data and set the
DC voltage (A) to the specified
value. (Note)
Press PAUSE button.
Procedure
00 Press PAUSE button
00
00

10. V-COM DC Adjustment (PK-064 Board)

Set the DC bias of the common electrode drive signal of LCD to
the specified value.
If deviated, the LCD display will be move, producing flicker and
conspicuous vertical lines.
Mode
Signal
Measurement Point
Measuring Instrument
Adjustment Page
Adjustment Address
Specified Value
Note 1: Perform "Bright Adjustment" and "Contrast Adjustment"
before this adjustment.
Adjusting method:
Order Page Address Data
1 0 01
2 A 02
3 4 F1
4 A 84
5 A 84
6
7
8
9 A 84
Note 2: Refer to table 5-2-2. "Hexadecimal-decimal conversion
table".
Processing after Completing Adjustments:
Order Page Address Data
1 A 02
2 4 F1
3 0 01
5-38
PLAY
Arbitrary
Check on the LCD screen
A
84
The brightness difference
between the section-A and
section-B is minimum
Procedure
01
03 Press PAUSE button
82
Change the data so that
brightness of the section A
and section B is equal.
Read the data and this data is
named Dref.
Convert Dref to decimal
notation, and obtain Dref'.
(Note 2)
Calculate D ' using
84
following equations.
(decimal calculation)
D ' = Dref' – 02
84
Convert D ' to a hexadeci-
84
mal number, and obtain D
(Note 2)
D Press PAUSE button.
84
Procedure
00 Press PAUSE buttton
00
00
A
B
A
B
B A
A
B
Fig. 5-1-22
.
84