XOCECO LC20H3D, Service Manual

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Check if fine tuning is normal.
Check if the output of earphone or loudspeaker is normal and if the picture is normal.
b).Interface of AV/S Terminals
Connect to access the signal of AV/S terminals separately and check if the picture or sound is
normal.
c).AV OUT Termianl
Input the signals separately in the status of TV/AV/S terminal. Connect AV OUT terminal to monitor
and check if the output picture and sound from AV OUT is normal. (Note: In the status of S terminal, the
output picture from AV OUT is colorless.)
d).VGA Interface
Input VGA signal(K7253 signal generator). Separately input the four types of VGA format signals as
listed in Table 1. Wait till auto calibration is over. Then check if the picture and sound is normal. If there
has been interference to the picture then press the auto set key on the remote control once again and
check if the display is normal.
Table 2.VGA format signal
screen size resolution Image clock(MHz) H-SYNC(kHz) V-SYNC(Hz) remark
640x480 @ 60 25.175 31.469 59.900
720x400 @ 70 28.322 31.469 70.086
800x600 @ 60 40.000 37.879 60.317
1024x768 @ 60 65.000 48.363 60.004
640x480 @ 75 31.500 37.500 75.000
800x600 @ 75 49.500 46.875 75.000
15”
1024x768 @ 75 78.750 60.023 75.029
640x480 @ 60 25.175 31.469 59.900
720x400 @ 70 28.322 31.469 70.086
800x600 @ 60 40.000 37.879 60.317
1024x768 @ 60 65.000 48.363 60.004
640x480 @ 75 31.500 37.500 75.000
800x600 @ 75 49.500 46.875 75.000
1024x768 @ 75 78.750 60.023 75.029
1280x1024@60 108 63.981 60.2
17”
1280x1024@75 135 79.976 75.025
640x480 @ 60 25.175 31.469 59.900
720x400 @ 70 28.322 31.469 70.086
800x600 @ 60 40.000 37.879 60.317
640x480 @ 75 31.500 37.500 75.000
CMOscreen
nonsupport
20”
800x600 @ 75 49.500 46.875 75.000
CMOscreen
nonsupport
e). YprPb Interface
Connect to access YprPb signal(K7253 signal generator). Separately input the five types of YprPb
format signals -- 480P/50 Hz,480P/60 Hz,720P/60 Hz,1080I/50 Hz,1080I/60 Hz and check if the picture
and sound is normal after auto calibration is over.
Connect to access YprPb signal(DVD signal generator). Input the signals -- 480I/50Hz,480I/60 Hz