SERVICE MANUAL LC-XB41 - TechEdu.com

Electrical Adjustments
Gain adjustment [Component]
1. Enter the service mode.
2. Receive the 16-step grey scale 480i-component signal
with Computer2 [Component] mode.
3. Connect an oscilloscope to test point “TP35G” (+) and
chassis ground (-).
4. Select group no. “0”, item no. “3” and adjust the amplitude
“a” to be minimum by changing the Data value.
(a)
White Level
n Common Center adjustment
1. Enter the service mode.
2. Receive the 50%-Whole Gray computer signal with
Computer1 [RGB] mode.
3. Select group no. “100”, item no. “92” and change
data value to “2” to reduce the panel frequency.
4. Project only green light component to the screen.
5. Select group no. “101”, item no. “1” and change data
value to obtain the minimum flicker on the screen.
6. Project only red light component to the screen.
7. Select item no. “0” and change data value to obtain
the minimum flicker on the screen.
8. Project only blue light component to the screen.
9. Select item no. “2 and change data value to obtain
the minimum flicker on the screen.
10. Select group no. “100”, item no. “92” and change
data value to “0” to reset the panel frequency.
b Auto Calibration adjustment [Video]
1. Enter the service mode.
2. Receive the 16-step grey scale composite video signal
with Video [Video] mode.
3. To start the auto-calibration for Component adjustment,
select group no. “260”, item no. “0” and then
change data value from “0” to “1”. After the auto-calibration
completed, "OK" will appear on the screen.
m 50% White adjustment [PC]
1. Enter the service mode.
2. Receive the 16-step grey scale computer signal with
Computer1 [RGB] mode.
3. Connect an oscilloscope to test point “TP35G” (+)
and chassis ground (-).
4. Select group no. “100”, item no. “6” and change data
value to adjust amplitude “a” to be 1.6 ±0.1V.
Below adjustment is performed when the above auto
calibration is failed.
Gain adjustment [Video]
1. Enter the service mode.
2. Receive the 16-step grey scale composite video signal
with Video [Video] mode.
3. Connect an oscilloscope to test point “TP35G” (+) and
chassis ground (-).
4. Select group no. “20”, item no. “0” and adjust the amplitude
“a” to be minimum by changing the Data value.
(a)
White Level
white level
, White Balance adjustment [PC]
1. Enter the service mode,
2. Receive the 16-step gray scale computer signal with
Computer1 [RGB] mode.
3. Select group no. “100” item no. “7” (Red) or “8” (Blue),
and change Data values respectively to make a proper
white balance.
(a)
white level
Confirm that the same white balance is obtained in video
and computer input.
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