Hi all

Just want to check what is going on with a DMD from TOTAN. When I got it, it looked like the display was out gassing (see pic). However I checked the voltages first and realised that it was actually being overdriven - I was getting about 145v and 133v on pins 1 and 2.

The high voltage section of the board was a mess. Very crispy and had been worked on before. I rebuilt the whole thing and now get nice 116v and 103v from the display driver board. However, the DMD no longer lights up at all. I installed another display, and this one lights up perfectly (see pic).

Has the old DMD been destroyed by being overdriven for so long? Or is it out gassed? It seems weird to me that it only works on the high (out of spec) voltages.

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Interesting! Did not know that. Thanks Chris.

Well, I spoke too soon. C28 on the display driver board just exploded. Lots of magic smoke. I'm not really sure what to do. I checked all of the traces were correct and it ran without issue for about an hour. Voltages to the display were good. Is there anything else I should check in particular, or just replace and monitor?

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The cap blew after the new display was installed. I will replace the cap and see what happens.

I would love to do this but the machine is not mine, and I can't convince the owner to drop A$750 on a new display!

Thanks Ken. I'll be checking my caps against this list in future. Won't be buying from that shop again...

I'm not in the US however I can get better quality caps from elsewhere so I will try that first.

The ones I installed were 220uf, 160v. Whether they were actually rated as it was written on the can is another matter.