LC-37HV4E (serv.man20) - Sharp TV Service Manual (repair manual). Page 17

5. Adjustment

5-1 VLSBIAS/15V voltage adjustment

Shift to Item of VLS BIAS cursor up/down key, and select the value by cursor right/left key. Connect the
digital voltage meter to MAIN PWB TP4101/No.30 pin of panel gate socket CN4102, and adjust to be
15.00±0.05V by the cursor up/down key.

5-2 GRAY LEVEL/14.5V voltage adjustment

Shift to Item of GRAY LEVEL by cursor up/down key, and select the value by cursor right/left key. Connect
the digital voltage meter to MAIN PWB TP4104/near IC4105, and adjust to be 14.50±0.05V by cursor up/
down key.
This adjustment should be correctly made because this power voltage is a reference voltage of tonal
voltage.

5-3 COMBIAS adjustment

Shift to Item of COMBIAS by cursor up/down key, and select the value by cursor right/left key. If the value is
varied by cursor up/down key, the test pattern is made, so adjustment should be made so that the flicker
near the screen center becomes minimum.

5-4 Background adjustment

With AVC center connected, start the set and adjust the display background.
Sequence:

~

Display the screen for adjustment/High-side 200 gradation & Low-side 48 gradation.

~

Adjust ROFFSET, GOFFSET and BOFFSET to allow 200-gradation patterns as a standard.
Adjust the chromaticity of High pattern/screen left to be x=0.278 and y=0.283.

~

Adjust R GAMMA, G GAMMA and B GAMMA to allow 48-gradation patterns as a standard.
Adjust the chromaticity of Low pattern/screen right to be x=0.235 and y=0.230.

The above adjustment can be made in the following method:

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Adjustment with RS-232C

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Prepare the personal computer with
WINDOWS95/98/Me/2000/xp inputted and provided with COM port/RS-232C, together with RS-232C
cross cable.

~

Start the set with RS232C cable connected.

~

Start the terminal software. The free ware normally found on the Internet is allowed.

~

The following should be set:
Baud rate        9600
Data             8bits
Parity            None
Stop              1bit
Flow control       None

~

If they are set correctly, press ENTER key on the personal computer. "ERR" appears atop the terminal
software.