Troubleshooting dead dmd
- Thread starter frolic
- Start date
sylvain
Active Member
First, check the supply voltages arriving on the DMD board, and connectors leaving the power supply.
Often the issue is with high voltage regulation parts on the power supply (diodes, transistors, resistors, caps).
Good luck !
- Sylvain.
Often the issue is with high voltage regulation parts on the power supply (diodes, transistors, resistors, caps).
Good luck !
- Sylvain.
Before you start swapping anything around, test the HV section with your DMM as Syl suggested. (also check the two fuses on the DMD controller) The HV section on these has a high failure rate.
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frolic said:
Yes, they are the same and TSPP is not the new style and plasma. I was just talking to Doug now and he said if you are going to do the swap test put the TSPP DMD into TOM. DMD's can develop internal shorts which would take out the HV and last thing you need is to take out your TSPP as well :evil:
Not sure how the Stern is wired up, but I thought I had a dead DMD on my TFTC until I realized I had plugged in a ribbon wire backwards... red strip is for pin 1!
...turns out it wasn't dead but just outgassed :FP:
...turns out it wasn't dead but just outgassed :FP:
PhilGreg said:
Here is what the back of the DMD on Spiderman looks like:
Here is my Star Trek The Next Generation for reference:
I don't think frolic's ribbon cable would be plugged in backwards as it has been working fine since he setup the game. Any updates or have you tried swapping the DMD or take any measurements with your DMM?
haven't had any time to work on this. One of my problems was we blew a fuse when diagnosising the DMD.
The fuse was on the dmd controller board, it was a 3/8 amp.
I went to Sayal, and all they sold was 250 and 500s.
Has anyone ever seen a 3/8 before? Is that normal? Can i use a 250 or 500 instead?
Once that fuse is replaced I can continue with the diagnosis of the original dmd problem.
The fuse was on the dmd controller board, it was a 3/8 amp.
I went to Sayal, and all they sold was 250 and 500s.
Has anyone ever seen a 3/8 before? Is that normal? Can i use a 250 or 500 instead?
Once that fuse is replaced I can continue with the diagnosis of the original dmd problem.
I have to ask how you managed to blow that fuse during diagnostics? And if you cannot get a 3/8, roll with the 250ma as I have used those in a pinch in that location. (and never ever over fuse!)
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thanks Doug. I can't recall exactly what happened, we were pulling the dmd out to start checking, pulling cables, something must have shorted from carelessness. The one thing for certain was it was AFTER the dmd went blank, so it is an unrelated problem.
Are 3/8 sold anywhere locally? I'll try the 250 for now since I have them and so I can at least continue checking it out.
Are 3/8 sold anywhere locally? I'll try the 250 for now since I have them and so I can at least continue checking it out.
I never buy my fuses locally because they are too expensive and never have what I'm looking for, unless I order 100pcs through my work. (yes, all the same value - 100pcs / bag)
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Brock came over tonight and installed his replacement dmd board which got it back up and running. Not sure what happened to the old one, he thought it looked a little fried. Guess it was an accidental short but I still don't know why it happened.
Oh well, was fun to play some TOM again tonight. Those shots are smooth like butter.
Oh well, was fun to play some TOM again tonight. Those shots are smooth like butter.
The original HV section on the DMD PCB's fail frequently, just the nature of the design. Glad Brock sorted you all out.
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