XOCECO LC-27FB18, Service Manual

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4
to access. Press “CH+” and “CH-“ to move cursor up and down, when the cursor stays on a certain
adjustment item, press “VOL-“ and “VOL+” to adjust. Press “MENU” exit to the level one factory
menu; press “EXIT” to exit from the factory menu at any situation.
Note: channel switch isn’t available at adjustment menu, only after return to level one factory menu,
you can switch channel.
3.2 adjustment of white balance
3.2.1 input 16 level gray-scale signal from VG849 to HDMI channel (TMIING: select a support
format of HDMI), enter white balance adjustment page of factory menu, select cool color
temperature of item, fixed WBGG_HDMI to 50H, adjust WBRG_HDMI, WBBG_HDMI, let the color
coordinate of third level on the right be (270,283) at 400nits; fixed WBBO_HDMI to 50H, adjust
WBRO_HDMI, WBGO_HDMI, let the color coordinate of third level on the left be (270,283) at 5nits.
The brightness of 400nits and 5nits may obtain by adjusting the contrast and brightness of menu.
3.2.2 input 16 level gray-scale signal from VG849 to AV channel (TMIING:968), enter white balance
adjustment page of factory menu, select cool color temperature of item, fixed WBGG_NTSC to 50H,
adjust WBRG_NTSC, WBBG_ NTSC, let the color coordinate of third level on the right be (270,283)
at 400nits; fixed WBBO_ NTSC to 50H, adjust WBRO_ NTSC, WBGO_ NTSC, let the color
coordinate of third level on the left be (270,283) at 5nits. The brightness of 400nits and 5nits may
obtain by adjusting the contrast and brightness of menu.
3.2.3 input 16 level gray-scale signal from VG849 to VGA channel (TMIING: select a support format
of VGA), enter white balance adjustment page of factory menu, select cool color temperature of
item, fixed WBGG_VGA to 128, adjust WBRG_ VGA, WBBG_VGA, let the color coordinate of third
level on the right be (270,283) at 400nits; fixed WBGO_VGA to 128, adjust WBRO_VGA,
WBBO_VGA, let the color coordinate of third level on the left be (270,283) at 5nits. The brightness
of 400nits and 5nits may obtain by adjusting the contrast and brightness of menu.
3.2.4 input 16 level gray-scale signal of 480I from VG849 to YPbPr channel, enter white balance
adjustment page of factory menu, select cool color temperature of item, fixed WBRG_YPbPr480I,
WBGG_YPbPr480I, WBBG_YPbPr480I to 128, and WBRO_YPbPr480I to 128, adjust
WBRO_YPbPr480I, WBBO_YPbPr480I, let the color coordinate of third level on the left be (270,283)
at 5nits. The brightness of 5nits may obtain by adjusting the contrast and brightness of menu.
Input format signals separately list on table 1, repeat the operation above until the white balance
pass muster.
Note: the white balance adjustment of VGA and YPBPR must be done at the situation that the white
balance adjustment of HDMI is accurate.
4 Performance check
4.1 TV function
Connect RF-TV terminal to the central signal source, enter the setup menu
→ auto search, check if
there is station skipping, the output of earphone and speaker, the picture are normal.
4.2 AV/S-VIDEO terminal
Input AV/S signal, check if the picture and sound are normal.
4.3 YPbPr/YCbCr terminal
Input YUV signal (VG-849 signal generator), separate input YUV format signal of table 1 and check
if the picture and sound are normal.
Table 1 YUV signal format
No H-frequency (KHz) V-frequency (KHz) Signal
1 15.734 59.94 SDTV 480i