Sony Cyber-Shot DSC-P72, Service Manual

Page: 56 / 74

6-36
DSC-P72
7. Contrast Adjustment (SY-85 board)
Set the level of the VIDEO signal for driving the LCD to the specified
value. If deviated, the screen image will be blackish or saturated
(whitish).
Note: Do either of “Adjustment without Using Oscilloscope” or
“Adjustment Using Oscilloscope”.
7-1. Adjustment without Using Oscilloscope
Mode PLAY ( )
Signal Arbitrary
Measurement Point Data of page: 40, address: 11, 12
Measuring Instrument
Adjustment Page 4F
Adjustment Address 8A
Specified Value 0D6 to 0DE
Adjusting method:
Order Page Address Data Procedure
1 00 01 01 Set the data.
2 40 F1 01 Write the data.
3 4F 02 03 Write the data.
4 40 10 00 Write the data.
5 40 10 90 Write the data.
6 40 11 Read the data, and this data is
named D
11A
.
7 40 12 Read the data, and this data is
named D
12A
.
8 40 10 91 Write the data.
9 40 11 Read the data, and this data is
named D
11B
.
10 40 12 Read the data, and this data is
named D
12B
.
11 Calculate D
A
and D
B
using
following equation.
(Hexadecimal calculation.)
(Note1)
D
A
= (D
11A
×
4+ D
12A
/ 40)
D
B
= (D
11B
×
4+ D
12B
/ 40)
12 Calculate the signal level using
following equation.
(Hexadecimal calculation.)
When D
A
D
B
Signal level = D
A
– D
B
When D
A
< D
B
Signal level = D
B
– D
A
13 When the signal level satisfies the
specified value proceed to step 16,
in case of others proceed to step
14.
14 4F 8A Change the data. (Note2)
15 4F 8A Write the data, and return to step
4.
16 4F 02 00 Write the data.
17 40 F1 00 Write the data.
18 00 01 00 Set the data.
Note1:
When dividing D
12A
or D
12B
by 40. If there is a fraction below
decimal point, truncate it.
Note2: When the signal level is smaller than specified value, decrease the
data.
7-2. Adjustment Using Oscilloscope
Mode PLAY ( )
Signal Arbitrary
Measurement Point CL803 (Pin
ws
of IC801) (VG)
Measuring Instrument Oscilloscope
Adjustment Page 4F
Adjustment Address 8A
Specified Value A = 2.94 ± 0.05V
Adjusting method:
Order Page Address Data Procedure
1 00 01 01 Set the data.
2 40 F1 01 Write the data.
3 4F 02 03 Write the data.
4 4F 8A Change the data and set the
voltage (A) to the specified
value.
5 4F 8A Write the data.
6 4F 02 00 Write the data.
7 40 F1 00 Write the data.
8 00 01 00 Set the data.
2H
A
White (100%)
White (100%)
Fig. 6-1-18.