Prima PS-42T8 Service Manual page 6

3.2.2 Enter factory menu mode (service mode)
Press the MENU button, press the number button: 1 → 9 → 7 → 9, enter factory menu, then use
VOL+/- select item value and CH+/- change it. Press the MENU button exit the factory menu.
3.2.3 VGA channel adjustment
3.2.3.1 VGA channel mode preset
Input VGA signal of K-7253, select 640*480/75Hz/85Hz, 1024*768/70Hz/75Hz/80/Hz/85Hz,
800*600/75Hz/85Hz, 1280*1024/60Hz/75Hz and 1600*1200/60Hz respectively, press "AUTO" to do
the auto adjustment until the screen is filled with picture.
3.2.3.2 ADC adjustment of VGA channel
Input the signal of 16 grades of grey density to VG-849 TIME921, PATTERN889, enter factory
menu, select ADC auto correction.
3.2.3.3 White balance adjustment of VGA channel
a. Input K-7253 8 level gray-scale signal of TIME303 (640*480/60Hz/) and PATTERN4718, enter
white balance adjustment menu; adjust the third and seventh levels using white balancer.
b. Select 9300k of "mode", fixed offset_R to 128, adjust offset_G and offset_B, let the color
coordinate of the third level be 285 and 290 and its brightness be 4.5-5nit. Fixed gain_B to 128,
Adjust gain_R and gain_G, let the color coordinate of seventh level be 285 and 290. Adjust offset_G
and offset_B and gain_R and gain_G repeatedly until the value of the two levels gray-scale to 285
and 290.
c. Select 12000k of "mode", fixed offset_R to 128, adjust offset_G and offset_B, let the color
coordinate of the third level be 270 and 283 and its brightness be 4.5-5nit. Fixed gain_B to 128,
Adjust gain_R and gain_G, let the color coordinate of seventh level be 270 and 283. Adjust offset_G
and offset_B and gain_R and gain_G repeatedly until the value of the two levels gray-scale to 270
and 283.
Note: after white balance adjustment, adjust 3.2.3.2 item, ADC auto correction again.
3.2.4 AV/TV channel adjustment
3.2.4.1 sub-brightness and sub-contrast adjustment
Input the AV color bar signal (PM5518 COLOUR BAR 100%) to VIDEO terminal, adjust the
sub-brightness and sub-contrast items of the factory menu, exit the factory menu and observe the
effect, repeat the adjustment until it become best.
3.2.4.2 white balance adjustment of AV/TV channel
a. Input AV signal (PM5518, 8 level gray-scale signal), enter white balance adjustment menu; adjust
the third and seventh levels using white balancer.
b. Select 9300k of "mode", fixed offset_R to 128, adjust offset_G and offset_B, let the color
coordinate of the third level be 285 and 290 and its brightness be 4.5-5nit. Fixed gain_B to 128,
Adjust gain_R and gain_G, let the color coordinate of seventh level be 285 and 290. Adjust offset_G
and offset_B and gain_R and gain_G repeatedly until the value of the two levels gray-scale to 285
and 290.
c. Select 12000k of "mode", fixed offset_R to 128, adjust offset_G and offset_B, let the color
coordinate of the third level be 270 and 283 and its brightness be 4.5-5nit. Fixed gain_B to 128,
Adjust gain_R and gain_G, let the color coordinate of seventh level be 270 and 283. Adjust offset_G
and offset_B and gain_R and gain_G repeatedly until the value of the two levels gray-scale to 270
and 283.
3.2.5 White balance adjustment of YPbPr channel
a. ADC adjustment of YPbPr channel: input the VG-849 TIME976 and PATTEN984 SMPTE Color
4