Sharp LC-37HV4M Service 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=0.283 and y=0.286 (LC-37HV4M)
~ 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=0.288 and y=0.278 (LC-37HV4M)
The above adjustment can be made in the following method:
~ Adjustment with RS-232C
~ 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.
x=0.276 and y=0.285 (LC-37HV4H).
x=0.271 and y=0.274 (LC-37HV4H).
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LC-37HV4M
LC-37HV4H