(Topic ID: 291262)

DMD Black screen

By saddys

3 years ago

Topic Stats

  • 4 posts
  • 2 Pinsiders participating
  • Latest reply 3 years ago by saddys
  • No one calls this topic a favorite


Linked Games

No games have been linked to this topic.

    #1 3 years ago

    Good morning, I have a problem with one dmd controller (Wpc 89).

    The screen on dmd is Black.

    In the past I have always bought kits at the various sites and they have always worked at the first shot.

    Then I decided to buy the individual components on aliexpress.

    I replaced all the components of the high voltage (mje, 2n,vary resistor, zener diode, etc) with components bought on aliexpress.

    Result: The screen is Black.

    The voltages, however, seem correct to me:

    The first time I turn on, I have these values
    -110v -98v 12v 4.95v 62v

    After a few minutes
    -114v -102v 12v 4.95v 66v

    If I connect a pin2dmd to the controller I see everything correctly.

    If I use another controller I see everything well on the dmd gas.

    So there's something about high voltage that I can't figure out the problem, because everything seems ok. Any advice?

    Can it be the poor quality of some component even if the values are correct?

    Thank you!

    #2 3 years ago

    Loaded or unloaded?

    Did you measure those voltages with display connected?

    #3 3 years ago

    With display connected!

    I have to measure without it too?

    #4 3 years ago

    So, new complete measure of faulty board:

    With dmd: -110v -98v 62v (measured offset 11.92v), after one minutes on, offset reached 12.02v
    Without dmd i have: -112v -90v 64v

    With another controller board that is ok on dmd, i have:

    With dmd: -118.2v -106.2v 67v (measured offset 12.04v)
    Without dmd: -120.4v -96.7v 67v

    With a third controller board that is ok on dmd, i have similar voltages of the first faulty board:

    With dmd: -111.3v -99.3v 65v (measured offset 12.01v)
    Without dmd: -112v -91.5v 66v

    The only "different" thing is the offset which is just below 12v (11.92v) at power on, but soon rises to 12v. If then I turn off and turn on quickly, the dmd will not turn on despite offsets of 12.02v.


    Wanna join the discussion? Please sign in to reply to this topic.

    Hey there! Welcome to Pinside!

    Donate to Pinside

    Great to see you're enjoying Pinside! Did you know Pinside is able to run without any 3rd-party banners or ads, thanks to the support from our visitors? Please consider a donation to Pinside and get anext to your username to show for it! Or better yet, subscribe to Pinside+!

    This page was printed from and we tried optimising it for printing. Some page elements may have been deliberately hidden.

    Scan the QR code on the left to jump to the URL this document was printed from.