Sharp LC-20SH4U, Service Manual

Page: 10 / 54

LC-20SH4U
10
SUPPLEMENT
[4] Initialization
4-1. Ground pins (81) and (82) of IC2001 (microprocessor) and turn on the power.
4-2. Make sure the screen size is set at 20 inches.
4-3. Make sure the model number is A630A.
(Adjustment Process Menu Page 1)
[5]
5-1. Model-by-model sending data
Separately published.
5-2. ROM collection
Separately published.
[6] Adjustment
6-1. Common bias adjustment
1) Feed a built-in signal.
2) Apply the specified instrument at the center of the screen.
3) Observe the instrument output on an oscilloscope.
4) Adjust the "COM BIAS" setting on Adjustment Process Page 2 so that the peak-to-peak of the wave be
minimized.
6-2. TAMP adjustment
1) Receive the standard color bar signal.
2) See if the "Y" reading (maximum) on Adjustment Process Page 2 is within the range in the following table.
If not, adjust the "NTSC TAMP" setting on the same page to have the "Y" reading (maximum) within this range.
Reference
(Adjustment Process Menu Page 2)
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
1
M O D E L 6 A A 3
2
O F
0
0
0
F
I N C H S I Z E
E R R O R N O R E S E T
P U B L I C M O D E
0
1
2
3
4
O F F E X T C O N T R O L
4
6
Model LC-20SH4U
Setting (NTSC) 155~158
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
2
C O M B I A S
4 5
5 1
0
5
5 1 8
5 1 8
2 1 0
T A M P L
Y D A T A
T A M P H
0
1
2
3
4
N T S C T A M P
5
6
Y Data
(White 75%)