Sharp LC-20D30U Service Manual page 16

LC-20D30U
7-3. White balance adjustment
1) Adjustment procedure (Call the AV input mode with INPUT2 or INPUT3.)
Adjust the white 40% setting at RGB CUTOFF2 first and then the white 80% setting at RGB-GAIN. (Set the
RGB GAMMA level at 0.9.)
(1) Test signal adjustment
[Input signal] Make the DVP-incorporated white balance test signal (white 80% on the left onscreen: 191-level
gradation, white 40% on the right onscreen: 92-level gradation) appear on the screen.
[Specifications] Adjustment Process Page 3: RGB CUTOFF2, RGB-GAIN
White 80%
White 40%
[Adjustment procedure with the bus]
Cut-off (RGB CUTOFF2) Fix the G CUTOFF2 setting at 0.
Vary the R/B CUTOFF2 settings accordingly.
Gain (RGB-GAIN) Fix the G-GAIN setting at 0.
Vary the R/B-GAIN settings accordingly.
(For the adjustment, use Minolta CA-210 at Engineering Department, and for the calibration, use
CH02"TOPCON" mode. Make measurements in the interchangeable mode with Production Department and
Production Engineering Department.)
7-4. Common bias adjustment
1) Generate the built-in signal.
2) Adjust the VR1 on the LCD control PWB until flickering gets minimum.
* Make this adjustment only when the LCD control PWB (CPWBX3335TPZZ) has been replaced.
[8] Factory settings
1) Hold down the "INPUT" and "VOL (–)" buttons of the set at once and turn on the power. Then keep pressing
the "CH (ù)" and "VOL (+)" buttons. (The "SETTING COMPLETE" message appears onscreen.)
2) Make sure that "SETTING COMPLETE" appears at the center of the screen a couple of seconds later.
SETTING COMPLETE
3) Turn off the power.
* Note: Immediately after making the factory settings, turn off the power switch. (At the next power-on, the set
gets started in the EZ SETUP mode. If any extra key-in is made after the factory settings are complete, the set
may run properly.)
Adjustment spec. / Inspection spec.
x=0.268 ±0.004
y=0.279 ±0.004
x=0.266 ±0.002
y=0.279 ±0.002
±0.01 Radius from center point
±0.01 Radius from center point
±0.01 Radius from center point
±0.01 Radius from center point
Adjustment range ±50
Adjustment range ±80
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