(Topic ID: 146911)

DMD just died, was a perfect dmd, no outgas

By balboarules

8 years ago


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    #1 8 years ago

    IS there anything I can do with this now, it was a perfect DMD, no lines out, not outgassed, it just died.. I confirmed in another game.. if not, anyone have a decent used one for sale, money is tight, I just laid out a ton on parts and repairs.. if anyone has one they are not going to use and can give me a good price, please pm me, or if someone knows someway I can save this one even better.

    Thanks
    Steve
    Balboarules
    CARGPB#37

    #2 8 years ago

    Just curious, are the voltages to it correct?
    --
    Chris Hibler - CARGPB #31
    http://www.Team-EM.com
    http://webpages.charter.net/chibler/Pinball/index.htm
    http://www.PinWiki.com - The new place for pinball repair info

    #3 8 years ago

    Yes, I hooked up another dmd from another game, and that one booted right up, then put the dead one in the other game and dead. One was for Addams which does not seem to be a good game for a weak DMD, but the other was DM, and that one seems to bring new life to older DMD's

    #4 8 years ago

    Yes...that's good. I want to know if the board is causing the two negative high voltages to draw together.
    I just fixed a DMD with this same issue.
    --
    Chris Hibler - CARGPB #31
    http://www.Team-EM.com
    http://webpages.charter.net/chibler/Pinball/index.htm
    http://www.PinWiki.com - The new place for pinball repair info

    #5 8 years ago
    Quoted from ChrisHibler:

    Yes...that's good. I want to know if the board is causing the two negative high voltages to draw together.
    I just fixed a DMD with this same issue.>

    What on the board would cause the high voltages to be drawn together? I lost my HV on my WPC95 and I am afraid to use my old DMD in another game in case it was the DMD that cause it. How do you test the DMD to make sure its ok and not causing these failures?

    #6 8 years ago

    So you fixed the dmd itself, or t he game? I am out about 1k in parts and labor between the two, spend 260 taking both CPUs to be checked, still need an elevator opto board, 200 for one rottendog, 35.00 on a used elevator opto board, 40 to pre order a new elevator. Board, 200 for a new solder station and solder sucker as I had a crap iron and hand help sucker...now I am down a dmd so I cannot do much repair on demo without a display!

    #7 8 years ago

    Can you check the voltages on the power connector that plugs into the DMD panel itself? There are two rails, one at about -108V and the other at about -120, that Chris is talking about. It's possible that the DMD panel itself is pulling them to the same voltage, which is bad.

    (Edit - if anyone has any dead DMD panels, and doesn't mind freighting them, I'm interested in buying them. Both totally dead and outgassed.)

    #8 8 years ago

    I've had a couple perfectly good DMDs just crap out instantly. This is out of hundreds I've had.

    But it does happen.

    #9 8 years ago
    Quoted from CrazyLevi:

    I've had a couple perfectly good DMDs just crap out instantly

    Yep, it definitely does happen. I suspect that it's the electronics going bad when that happens, rather than the plasma panel itself, so probably repairable (though would often take a lot of work).

    #10 8 years ago
    Quoted from balboarules:

    260 taking both CPUs to be checked

    Ouch. Seems high depending on the repair necessary.

    Quoted from balboarules:

    So you fixed the dmd itself?

    The electronics on the display. Documented here.
    http://www.pinwiki.com/wiki/index.php?title=General#DMD_Display_Panel_Repair

    Quoted from falco:

    Can you check the voltages on the power connector that plugs into the DMD panel itself? There are two rails, one at about -108V and the other at about -120, that Chris is talking about. It's possible that the DMD panel itself is pulling them to the same voltage, which is bad.

    Exactly.
    How to test voltages...
    http://www.pinwiki.com/wiki/index.php?title=Williams_WPC#Testing_DMD_Controller_Power

    --
    Chris Hibler - CARGPB #31
    http://www.Team-EM.com
    http://webpages.charter.net/chibler/Pinball/index.htm
    http://www.PinWiki.com - The new place for pinball repair info

    #11 8 years ago

    -122
    -136

    The repairs included parts and a ACIS chip, and the burning of a new rom.

    #12 8 years ago
    Quoted from ChrisHibler:

    I just fixed a DMD with this same issue.

    Thanks Chris!

    #13 8 years ago

    they seem too high to me

    #14 8 years ago

    Sorry, got confused with something else that I needed, actually it was 180 for the repairs and parts including the ASIC chip and the rom.. plus I had a socket installed to add the battery eliminator and I bought 4 U shaped opto sockets all this was 160. There were 2 other sockets replaced as well.

    #15 8 years ago

    Those voltages are too high. While they might work, in the past when I've seen voltages that high, the display would have a "plasma affect" where images that were supposed to be on the display would have surrounded by dots that were not supposed to be lit. And, while I can't say with certainty, those high voltages may be a factor in the death of that display panel.

    I'd take a look at the HV section of the dot controller card.
    --
    Chris Hibler - CARGPB #31
    http://www.Team-EM.com
    http://webpages.charter.net/chibler/Pinball/index.htm
    http://www.PinWiki.com - The Place to go for Pinball Repair Info

    #16 8 years ago

    At least the 12V differential is there. Well, 14V, but that's probably not fatal, so the row driver logic should be happy. As Chris says, I'd definitely check the power supply, that seems too far out of spec. Maybe it is low enough that it's exploded the row driver or panel. I'd expect the panel to do weird things for a while before failing, though.

    #17 8 years ago

    I took one dmd from another game and put it into Addams, and it is working, that game has an aftermarket DMD board in it from either Pinled or Pinbits, I cannot remember off the top of my head, and I honestly do not want to take the glass off the head now that it is working 100% again, my poor Demo man is going to be waiting a while for parts.. I have no idea what happened, but I had a few pinsiders offer me some decent deals on used DMD's so I have one coming to put into Demo man, I am still going to attempt to fix this one, as it was PERFECT before Addams started having all the issues..

    I broke my own personal rule on this one, and it cost me, DO NOT TAKE WORKING BOARDS OUT OF WORKING GAMES TO TRY IN A GAME WITH ISSUES... I went from Demo Man down, to Demo and Addams down because of this, and lost a DMD, bought a new CPU board, spent way too much money especially at this time of year. I should NEVER have broken my own rules.... Grrrrrrrr!

    Thanks for the help guys, appreciate it as always, Happy Holidays to all, especially my CARGPB brother Chris...

    Steve
    Balboarules
    CARGPB#37

    #18 8 years ago

    Ok, I just put the Babcock into Demo Man and turned it on, measured voltages on the connector of the DMD itself not the connector from the game

    1. 64.5
    2. 8.0
    3. 4.9
    4 0
    5 0
    6 0
    7 -87.9
    8 -110.4

    Still trying to find somewhere with information on what I could possibly do to save this display, it was perfect, not outgassed, no lines out.. strong display, I hate to just toss it.

    Thanks

    #19 8 years ago

    I note that pins 7 and 8 have a 22V difference. This should be only 12V. If you didn't have a display connected when you took the measurement, those voltages would be about right as the lower of the two negative voltages often tests low when not under load. Also, pin 2, is supposed to be about 12VDC.

    Shoot a picture of the back of the display. I want to see what kind of row and column drivers it has on it.
    --
    Chris Hibler - CARGPB #31
    http://www.Team-EM.com
    http://webpages.charter.net/chibler/Pinball/index.htm
    http://www.PinWiki.com - The new place for pinball repair info

    #20 8 years ago

    DSC01948.JPGDSC01948.JPGDSC01949.JPGDSC01949.JPGDSC01950.JPGDSC01950.JPG

    #21 8 years ago

    In your DM, the voltage readings with a known working display connected are normal, right?
    It's the Problematic Babcock display that causes the lower negative voltage to vary from nominal, right?
    --
    Chris Hibler - CARGPB #31
    http://www.Team-EM.com
    http://webpages.charter.net/chibler/Pinball/index.htm
    http://www.PinWiki.com - The new place for pinball repair info

    #22 8 years ago

    That is correct

    #23 8 years ago

    One of those ICs on the back is FUBAR.
    I can't say which one.
    I'd get an identical display and do some probing around. It's the same design that Vishay/Dale used.
    --
    Chris Hibler - CARGPB #31
    http://www.Team-EM.com
    http://webpages.charter.net/chibler/Pinball/index.htm
    http://www.PinWiki.com - The Place to go for Pinball Repair Info

    #24 8 years ago

    I would not even know what to probe around for my friend..

    #25 8 years ago

    It was Tom Brady he deflate it hehe!!!!

    #26 8 years ago

    11-2 clinched the division already.. We love Tom Brady!!!!

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