I m trying to replace a burned in DMD and the new one tests perfect, and displays the score and other text perfect, but the pictures/animations are horrible. I've reseated and swapped back and forth - the problem definitely is in the DMD - any thoughts besides chuck it and buy another?
Original DMD - burned in, but functional
Replacement DMD that tests fine, but obviously isn't well
I'm no help...never have seen that. Would love to know the cause.
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The only thing I would do before going in for another DMD is to check your DMD voltages at the DMD. Other than that it appears to be a problem with the new replacement DMD.
Notice how all the full bright tones are represented. It's the half tones that are missing. I read somewhere that there are different signals sent to each pixel. Something like 100%, 75% 50%.
If the other signals are out.
Would "test" only test the high beams?
faz
Quoted from pinball_faz:Notice how all the full bright tones are represented. It's the half tones that are missing. I read somewhere that there are different signals sent to each pixel. Something like 100%, 75% 50%.
If the other signals are out.
Would "test" only test the high beams?
faz
Good observations - I didn't see anything but high beams in the test mode. If this theory is true, then I might benefit from something simple like reflowing connectors on the DMD board. Its an SMD board, but the pins should be workable.
Quoted from TrainH2o:Did you run the DMD test? How does that look?
Perfect.
Quoted from PinballManiac40:Looks like that you're trying it in Ironman. What does the new DMD do in the TZ ?
Haven't tried - could try in a whitewater tomorrow. TZ is all folded up in the shop awaiting restoration. Do you have a theory as to why it might behave differently?
Quoted from btw75:Haven't tried - could try in a whitewater tomorrow. TZ is all folded up in the shop awaiting restoration. Do you have a theory as to why it might behave differently?
I didn't notice you had a whitewater. That will work too.
no theory yet, just maybe it will help us understand the problem a bit better. Also this will help eliminate cables and DMD controllers as an issue working with that DMD.
And it will be helpful if you were going to send it back for repair/replacements under warranty. Had this new display long?
Quoted from btw75:I just bought it used - was likely to just ask for my money back or swap for another, but figured I'd be thorough as I could troubleshooting first.
So the DMD is not new? Oh boy....I smell ebay, "worked great last time we used it" but sold as is?
Try it in another pin and see what it looks like...WW will work.
Ok - so I swapped it into my NF. Different issue here - every row of txt has a sketchy top line - a little blinky/half tone, but animations work fine. As a negative test, I also swapped the known good NF DMD into IM and it worked fine. The problem is clearly with the DMD but it manifests itself differently on the WPC-S machine vs the SAM. I just don't know where to start troubleshooting the DMD itself, so we'll see about swapping or a refund and call it a day unless someone has a DMD repair thought.
PS - No worries on who sold it to me, no mal-intent involved.
Sounds like a tough problem to work on. Need a good technique for replacing surface mount parts as well.
I vote for trying to get a replacement for the replacement DMD.
Quoted from btw75:Ok - so I swapped it into my NF. Different issue here
This almost sounds like a cold solder joint on the DMD. Why would the behavior change this much on two machines?
Oxidation on contacts? Bent? Cold solder joint?
My 2¢.
faz
Quoted from pinball_faz:This almost sounds like a cold solder joint on the DMD. Why would the behavior change this much on two machines?
Oxidation on contacts? Bent? Cold solder joint?
My 2¢.
faz
I was wondering if it has to do with differences in the way Stern and Williams addressed the DMD?
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