AT20 scanners

[ghostgeek]

I have a laser projector that uses Chinese made AT20 scanners and amps. The amps are in need of tuning, but I can't seem to find any schematic or diagram of the trim pots on the boards.

Does anyone happen to know what each of the pots on these boards correspond to?

Thanks.

 

[farbe2]

Just try the pots.
If you have never tuned drivers before, you will not get good results even if you have a pot labeling diagram.
If you have experience tuning drivers, you can deduce the function of the pot by just turning it a little and looking at the output.

The pots are likely gain, hfd, lfd, scale/size, offset/linearity and feedback led current.
Some drivers also have feedback gain. As there are 6 pots, its likely the first 6 I mentioned.
Size is easy to spot -> changes picture size
Gain is also easy -> changes sharpness, less gain, more overshoot.
hfd and lfd change the overshoot, HFD is high frequency, LFD is low frequency damping. Also easy to spot on corners.
Offset/linearity will just change the picture center a little.
Feedback stuff is a little harder. These pots most like do not change much if anything on the output, so leave them alone.
For tuning, you just need LFD/HFD/Gain.