URGENT HELP NEEDED please!! Major problem on my projector right before an event...

Hi guys, I need some quick help to correct a major problem :(

Today I installed a new quad RED module (as in this post).

At home it worked nice, but I noticed a strange problem : the red was at full power if the ground of the power supply was touching the main board of the laser. So I disconnected that, and that seemed to work.

So, tomorrow I have an event with my projector, I installed the it and all that, but I noticed that RED laser was on full power all the time now!!! I discovered it was a strange ground loop between my portable computer and the projector. I corrected (temporarily) the problem by removing the earth on my portable computer power supply.

But some hours later, the problem reappeared by itseld, and nothing to do to correct it!!! I think it's a problem related to the new RED module and its driver (FlexMod N2), as before I never had that problem.

--- All the diodes are already insuled individually from the base plate ---


So I am really really annoyed now, I had to unmount my projector and take it back to home... Does anyone can help me before I return to the location tomorrow? I'll be infinitely recognizing!!!

Put an isolation transformer in the projector.

I'm not sure it will work. The ground is going from my portable computer to the USB to the FB3, which go to the projector ground.
Maybe I should remove the earth or ground connection on the FB3, but don't really know why doing that...

You can also power your FB3 from USB, if that helps.

There's either a jumper, or a spot to solder one in. (two pins)

I did that with mine at SELEM last year after getting a phantom ground. Of course, you'd want your computer to be on the same circuit as your projector, ideally.

-Jonathan

FB3 was already powered by USB...

I think problem is resolved now :( Seems like all my diodes, the driver and my gain/offset board have just DIED :( :mad: :mad: :mad: :mad: :mad: :mad: :mad:

Hopefully, my green and blue lasers are still alive.

So I go to bed now, and tomorrow I'll have the choice between re-installing my old red or to suicide myself...

Hi, I posted this in your other thread..

sbk, very nice workmanship! I like the design. I can see that you isolated the diode cathodes from the casing with thermal pads, good but I see some gaps in the insulation at pressure points. Make sure that this hasn't shorted out for any of them. You can do a reistance measurement with the power off from the diode case to the mounts. Other than that, the driver operation is simple: mod- is the same potential as power -, the controller should drive mod+ from 0 (off) to 5V (full on)