BenQ PB8220 - XGA DLP Projector, Service Manual

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Chapter 5 Alignment Procedure
1. DMD Bias Voltage Alignment
Equipment:
- None
Procedure:
1. Watch DMD chip Label (Example: 9477000 0234
B )
2. Switch the DIP switch on DMD board according to the red character on the DMD chip
0 0
3. 00: B
01: C
10: D
11: E
2. Color Wheel Delay Alignment
Equipment:
- Battery Biased Silicon PIN Detector
- Oscilloscope
- Probe
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 “
Æ ” and “ Å ” 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
Ahead Exact Lag
6 3