Hong Kong! (Bet you haven't heard that before)

[The_Doctor]

Autopsy time.

Ok, go through those minutes carefully in your mind. Sit and recall each moment as best you can. I won't try to guide you too much on this, can't do much worse than put useless ideas in the mind of a person trying to learn, but there are two things to try to remember specifically: Did you see, or add, many reflections of that light that might have got back to the diode? And can you remember a specific detail on that light; was it a sharp, deep specular (grainy) red, or was it in any way washed out, smeared or pastel-shaded even when no other colour was mixed with it? Try to recall carefully from whatever impressions you have, now, before memory fades. Details at this point might determine cause of death and help you any number of times in the future. The more you get this right early, the less diode's you kill. Odds are you did nothing wrong here, but never mind, the thing is to know what happened, because even if blame matters some time it can't be placed without knowing why.

[silentgloves]

Ok, so I have a cheapo DMX controller laying around. Hooked up the DMX, started tinkering (the projector didn't come with a manual so I was mapping out what each channel did). My goal was to program chases with the built-in patterns with the Y-axis reduced about 50%. Figured out which channel controlled the Y zoom. Started programming scenes into the DMX controller. Suddenly, I noticed Purple, Yellow and Red were gone, and white was cyan. There was no fade out. At first, I thought that I might have been sending something weird via DMX. So I shut everything down, reset the DIP switches to auto mode, and let it run with the key off (thought it might have over heated).

After letting it cool for about 20 minutes, I fired it up in auto mode. No red.

The only reflecting surface in the beam path was a copper pipe which I masking taped over prior to using the projector, and about 30 feet away, there was a CFL bulb. One of those screw in ones, I didn't think that would be much of an issue given it wasn't directly in front of the beam, off to the side about 5 feet, and pretty far away.

Edit: When the red was working, it was bright, crisp and lovely. The red diode is a 300mw 638nm.

[silentgloves]

Here it is working. It's pointing up into the rafters because I didn't want to blind myself, but there's nothing reflective there. I just went down and looked to verify. https://www.facebook.com/photo.php?v...78376277773786

[silentgloves]

Regardless of this little mishap, I'm sooooo hooked. All my other hobbies just flew out the window with my cheap, chinese red diode.

[The_Doctor]

I think you need a real picture host. I can't see that. Facebook seem to know as much about simple image hosting as Heath Robinson or Rube Goldberg.

Anyway, your best shot might be to see if the diode is easy to replace yourself, as the diodes are cheap enough. If you can find some half-power images frames that make steady patterns that let you see individual diode outputs at leisure, you might get some easy time analysing, otherwise you're s**t out of luck, my autopsy idea was based on the assumption that you had some simple set of conditions. I should have known better. Cheap scanner system usually tries to impress by doing everything at once as fast as possible...

What you might test if possible, is your scan controller output. See if it overshoots safe voltage limits. It is possible that the laser's own driver can't handle that when it should. it doesn't seem like you did anything it shouldn't have been ok with, but anything you can do to eliminate possible causes is worth doing now, before you get a new diode to try. You might get some inspired idea about what went wrong the day after, too. If reflections were involved, it sounds like internal ones, your room sounds about as safe as it gets for reflections unless you're firing many watts around (at which point you worry about the soft furnishings more, probably.

[silentgloves]

Thanks man, I appreciate your help.

I tested all the rail voltages coming from the PSU. 12.82V on the mains that supply the single RGB laser module. Other voltages seem to be around 8V or 5V. I have a picture, it's an all-in-one RGB unit:



So I doubt I'll be replacing a single diode in that unit. It'd be great if I could pull that one out, send it back, and have Goldenstar ship me a new one. Winni?

[silentgloves]

Here it is running in lonely GBC mode.

[silentgloves]

Even without red, my house parties are still exactly 1,431 times cooler than anybody else's on my block. I have 2,800 Watts of EV sound, I figure that makes up for a missing red diode, at least for one party.

[The_Doctor]

Looks like a nice layout in the case, one module that could save a lot of postage charges compared to the whole thing. Supply volts sound convincing (for what little I know about the specifics there). I was thinking of your DMX controller though, if that's putting analog signals to a laser driver, and has overshoot of its own, it may be that a diode driver is faithfully trying to copy a dangerous signal instead of limiting it as it should. The one thing you can find out (if you have an oscilloscope) is whether the controller is doing this or not.

Going to leave this for others now, I ran out of good ideas.

[silentgloves]

Unfortunately, I do not have an oscilloscope. Thanks anyway. I paid $365 for this thing shipped, even with a broken red diode, it's still quite impressive for the price. The circles are genuine circles (I'm not sure why, but this seems relevant). Even running animations there isn't any flicker, which seems decent for 20k.

Goldenstar was quite responsive pre-purchase. Let's see how they do when I have a problem to determine if I shop there again.