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(Topic ID: 266162)

Judge Dredd missing letters on DMD

By mermaidlover

4 years ago



Topic Stats

  • 6 posts
  • 5 Pinsiders participating
  • Latest reply 4 years ago by Crash
  • No one calls this topic a favorite

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    Judge Dredd 3 (resized).JPG
    Judge Dredd 2 (resized).JPG
    Judge Dredd 1 (resized).JPG
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    #1 4 years ago
    OP
     
    ???

    mermaidlover

    Pinside member

    US Macon, GA

    9y 16,250 2

    Judge Dredd letters on DMD are missing. Have replaced ribbon cables. Have repaired DMD controller and swapped with a known good one. Using a Rottendog MPU because of battery damage on original. replaced bottom connectors on MPU. Don't have an MPU DCS to swap. Can anyone help? Won't go into test, but test button works and causes sound like a muffled gunshot. First image is what displays when test button is pressed. Weird. Thank you for your help.

    Judge Dredd 1 (resized).JPGJudge Dredd 1 (resized).JPGJudge Dredd 2 (resized).JPGJudge Dredd 2 (resized).JPGJudge Dredd 3 (resized).JPGJudge Dredd 3 (resized).JPG
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    #2 4 years ago
     
    PAR

    PAR

    Pinside member

    10y 29,850 48 8

    If you can't get into tests sounds like a CPU board connection issue, are there dip switches on that particular rottendog cpu?
    Maybe reseat the chips on the CPU too?

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    #3 4 years ago
     
    ???

    pinmike

    Inactive member

    US Bossier City, LA

    13y 56,600 5,368

    Reseat the game roms

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    #4 4 years ago
     
    ABC

    Crash

    Pinside member

    12y 141K 14,136

    Whoa, that's bizarre. I've never seen anything like that that. It appears the ASCII text data streaming from the CPU to the DMD controller is getting corrupted.

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    #5 4 years ago
     
    TK

    Tuukka

    Pinside member

    FI Lempäälä

    5y 78,350 1,761 16 18

    The data from CPU to DMD controller is bitmap images, not ASCII text. Looks like DMD controller RAM addressing problem. Maybe the buffer chip in CPU board, that outputs data/address to DMD is failing.

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    #6 4 years ago
     
    ABC

    Crash

    Pinside member

    12y 141K 14,136

    You're right, I forgot the image data is in the CPU ROM on WPC games.

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