LG RD-JT51, Service Manual

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OSD Default value:
Item Value Item Value
DLP Brightness 32 CW Delay Adjustable
DLP Contrast 32
White Peak 10
The default values let optical engine to get maximum contrast and brightness.
Procedure:
1. Probe impedance matches 50 ohm
2. Open Factory OSD, and select color wheel delay item
3. Leave the image pure red (DMD red curtain)
4. Put the detector on the screen that red image was projected.
5. Watch the oscilloscope and notice the square waveform
6. Use the
“ ” and “ ” key to increment or decrement the color wheel delay value
7. No matter the waveform is square or not, let the waveform was lagged first
8. Then increment or decrement the value to let the waveform to be square
9. Do not adjust too much, let the signal get ahead, if it happens, go back to step 7
and do it again.
10. Change the input to pure blue and repeat the above procedures again.
11. Change the input to pure green and repeat the above procedures again.
3. Formatter board check procedure
Equipment:
- Pattern generator
Procedure:
1. Connect power, D-sub, into projector.
2. Light on projector.
3. Testing below patterns and resolution is
1024*768@60Hz (XGA); 800*600@60Hz
(SVGA)
(1) General-1 pattern. (Pattern 1)
(2) 32 grays pattern. (Pattern 48)
(3) White pattern. (Pattern 41)
(4) SMPTE pattern. (Pattern 5)
4. The formatter board would be note fail if above three image-quality is not good.
5. Test the connection between formatter board to keypad board and IR board.
6. The formatter board would be note fail if there are some wires is broken in
formatter board.
Lag Exact Ahead