XOCECO LC30B1, Service Manual

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6) Power for liquid crystal screen C159 anode 12 V±0.3 V
7) AD9883A power C410,C17 3.3 V±0.1 V
c) Connect VGA line, small conversion board of RS232 electric level and PC set, then run the
program for FLASH upgrading. Turn on the power adapter switch and then the indication lamp
of infrared receiving board should be in off state. About 4 minutes later, upgrading is completed
and the indication lamp turns red.
d) FLASH write DDC program
2.5 Adjustment and calibration of TV board
2.5.1 Connect main board, TV board and infrared receiving board. Turn on the power supply adapter
switch and the indication lamp of the infrared receiving board will be in green. Measure TV board
X2 and PIN3 = 5 V±0.2 V.
2.5.2 Press the menu twice in the TV state to enter the item of sound adjustment. Then move the
cursor to the item of equilibrium. Open the cover of remote control set. Press the mute key at the
upper left corner and enter the factory menu. Press the menu key again and you can see the
preset item of ex-works. Select this preset item and press volume key (+ or -) once to execute
the ex-works presetting. The press confirm key to exit the factory menu.
2.5.3 Press channel key +/- to access the ex-works preset channel and check if the screen display is
normal.
2.6 Adjustment of white balance(Use white balance meter CA210 and signal generator K7253
specialized for LCD. )
2.6.1 Assemble the complete set.
2.6.2 Press “signal source” key to enter YpbPr.
2.6.3 Input signal YPbPr:640x480p 60 Hz (K7253).
2.6.4 Enter user menu and set the brightness to 50 and contrast to 50. Press factory key to enter
factory menu. Input dark field and execute “black calibration”. The input white field, execute
“white calibration” and then finish.
2.6.5 It’s unnecessary to do white balance adjustment for other channels.
2.6.6 For color coordinates, refer to Table 1.
Table 1 Color temperature coordinates
Color temperature Color coordinate X Color coordinate Y
9300K 0.281±0.020 0.311±0.020
7300K 0.298±0.020 0.321±0.020
6500K 0.313±0.020 0.329±0.020
3 Performance check
3.1 Station searching function of TV
Enter station searching menu → auto station search. Connect RF port to central signal source.
After system is set up, check if there is station skipping. Check the semi-auto search and see if
the fine adjustment is normal.
3.2 AV/S terminals
a) Connect AV and S terminals and check if they are normal.
b) Press the video key of the remote control and switch the picture frame
to the state of AV and S-VIDEO. Check if the color is normal and if there are mixed lines, snow