Sanyo PLC-XU22E Service Manual page 31

Electrical Adjustments
WHITE UNIFORMITY ADJUSTMENT
This adjustment should be carried out when existing unbalanced white uniformity on the screen or after replacing
the LCD panels. (When replacing the main board-A, the memory IC, IC302 on the main board-A should be
replaced with the one on previous board, so that the white uniformity adjustment may not be required because
the data of white uniformity adjustment are stored in this memory IC, IC302.)
White uniformity compensation adjustment system of this model divided the screen into 13 in vertical direction and
16 in horizontal direction and specified the area by using its co-ordinate, and then adjust the RGB white balance
on the specified area, refer to the figure below.
Please note that the selected area and dividing lines are not indicated on the screen. Roughly select the area you
wish to adjust with vertical and horizontal address number as shown figure below.
[Before adjustment]
- Set to normal display mode.
- Confirm the white uniformity compensation mode on.
Enter to the service mode , select item no. "83" and confirm that the data value is "186" (mode On). If the data
value is "58"(mode OFF), change value to "186" by pressing the VOLUME
- Initialize the all of compensation data. (This is required when the LCD panel is replaced more than 2 panels.)
1) Enter to the service mode, select item no. "82" and increase the data value from "0" to "10". When the value
reaches "10", the data value is automatically return to "0" and the initializing has been completed. The all of
compensation data for RGB are to be "32".
- Mode : Video or Computer mode
- Input Signal : White raster signal
- Picture control : Normal level
[How to adjust white uniformity]
[1] Enter to the service mode.
[2] Chose the area you wish to adjust. For example, choosing 3rd area from the top and 10th area from the left.
Select Item No. "77" (Vertical area no. selection mode) and select Data No. "2" , and select Item No. "78"
(Horizontal area no. selection mode) and select Data No."9" . The area no. starts from "0".
[3] Adjust white balance in selected area.
Select Item No."79" (Red), "80" (Green) or "81" (Blue), and change data value to adjust white balance.
[4] Repeat steps 2 to 3 until obtaining better white uniformity.
[5] Exit from the service mode.
0 1 2 3 4 5 6
0
1
2
3
4
Service Mode
5
Video
6
7
8
9
10
11
12
9
7 8 10 11 12 13 14
Item Data
77 2
15
Item : <77> Data : <2>
Item : <78> Data : <9>
Item Initial Value Range
77 0 0 ~ 12
78 0 0 ~ 15
79 32 0 ~ 63
80 32 0 ~ 62
81 32 0 ~ 62
82 0 0 ~ 10
83 186 58 or 186 White uniformity comp. On/Off
-30-
or VOLUME button.
Description
Vertical area no. selection
Horizontal area no. selection
Red white balance adjustment
Green white balance adjustment
Blue white balance adjustment
Reset of white uniformity comp. data