Service manual

14
LC-20B8U-S
LC-20B9U-S
LC-20B9U-SM
(Onscreen display of adjustment process menu page 1)
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[5] Adjustments
5-1. AD converter level adjustment
1 D3 input
1) Feed only the Y component of D3 75% color bar signal.
Equipment used: LEADER LT446
Signal name: COLOR BAR 75%
Setting: 01: 1920 x 1080 / 60i
H: 33.72 kHz, V: 29.97 Hz
2) Turn on the AUTO GAIN-OFFSET1 item on adjustment process page 7.
2 PC input
1) Feed the VGA white 0% signal.
2) Turn on the AUTO OFFSET2 item on adjustment process page 8.
3) Feed the VGA white 100% signal.
4) Turn on the AUTO GAIN2 item on adjustment process page 8.
5-2. Common bias adjustment
1) Adjust the "COM BIAS" setting on adjustment process page 2 so that flickering gets to minimum. With the
setting changed, the flicker check built-in test pattern will show up.
5-3. TAMP adjustment
1) Receive the 75% standard color bar signal in the TV input mode.
2) If the "YDATA" reading on adjustment process page 2 is not within the range in the table below, readjust the
"NTSC TAMP" item on the same page and make sure the "YDATA" reading is as specified.
* Note that the setting range may be different from model to model.
3) Then add 6 to the "NTSC TAMP" setting and enter this value for "PAL-M TAMP" and "PAL-N TAMP".
Model LC-20B8U LC-20B9U
Setting 155-158 155-158
[4] Initialization
4-1. Connect both pins (81) and (82) of IC2001 (microprocessor) to GND, and turn on the power.
4-2. Make sure the model number "A628" is selected. *Note: This setting cannot be changed.
4-3. Make sure "20" (inches) is selected for the screen size. *Note: This setting cannot be changed.