AOC C787 Service Manual page 11

E. To switches the input signal to the other Timing Mode. Please follow step C ~ D to get the optimum picture.
F. Select the "
returned to the original OSD window.(user's operating condition)
G. The setting data of the CONTRAST, BRIGHTNESS, PIN-BALANCE, PARALLELOGRAM, ROTATION,
COLOR TEMPERATURE are common mode saved in the memory. Don't needed adjust it individual at every
timing Mode and save in the memory.
H Model select: for factory only, service engineer can't changed.
3. White Balance, Luminance adjustment:
A. Bias (Low Luminance) adjustment:
(a) Set mode 2 640 × 480 Fh: 31KHz full white pattern.
(b) To make the adjustment condition is under the Factory preset window.
Same as step 2-C.
(c) Warm up more than 20 minutes.
(d) Brightness
make Y= 1.0FL ± 0.2FL
(e) Brightness set to raster just cutoff, adjust contrast to be 4FL, then adjust G-Bias
Bias
temperature x= 281 ± 10, y= 311 ± 10.
B. Gain (High light) adjustment:
(a) Set mode 2 640 × 480 Fh: 31.5KHz full white pattern.
(b) Brightness set to raster just cutoff and set the contrast to max.
(c) Adjust G-Gain
C. Recheck item A&B to make sure both of them in spec. Finally select OSD function to the 9300°K function, then
press the MENU Key. To make the setting data saved in the memory.
D. The adjustment of 6500°K white Balance, May follow step A ~ C , with the x=313 ± 10, y=329 ± 10.
E. Full white luminance:
(a) Set mode 2 640 × 480 Fh: 31.5KHz full white pattern.
(b) Image Size : H:300±4mm V:230±4mm.
(c) Brightness set to raster just cut off and set the contrast to max.
(d) Adjust VR701 to the luminance at 30 FL ± 2FL.
4. Focus Adjustment:
A. Set mode 2 640 × 480 Fh: 31.5KHz with character full page.
B. Adjust brightness to center and contrast to max.
C. Then adjust focus VR1 to a fine vertical line.
D. Adjust focus VR2 to a fine horizontal line.
E. Repeat step C & D..
5. Purity Adjustment
A. Be sure that the display is not being exposed to any external magnetic fields.
B. Ensure that the spacing between the Purity, Convergence, Magnet, (PCM), assembly and the CRT stem is
29mm .(See below diagram)
C. Produce a complete, red pattern on the display. Adjust the purity magnet rings on the PCM assembly to obtain a
complete field of the color red. This is done by moving the two tabs in such a manner that they advance in an
opposite direction but at the same time to obtain the same angle between the two tabs, which should be
approximately 180'.
D. Check the complete blue and complete green patterns to observe their respective color purity. Make minor
adjustments if needed.
" RETURN function and press the MENU Key, then the Factor Preset window will be
set to maximum. Contrast
, to make the setting value is(20), then adjust the R.G.B Bias individual to the color
, B-Gain , R-Gain
set to min. full white pattern, then adjust FBT screen VR to
, to make color temperature x=283 ± 10, y=297 ± 10.


10
, B-Bias , R-