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(Topic ID: 232585)

Stern Stars wacky display issue

By lowkeyfilms

5 years ago



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    #1 5 years ago
    OP
     
    BMX

    lowkeyfilms

    Inactive member

    US Clearwater, FL

    8y 19,150 22 5 7

    Stern stars w rebuilt driver board.

    Displays all have 22. On them and scoring is random. It mostly just puts 2's, 3's 6's and 7's with no ryme or reason.

    All other funtions work. (Except pop bumper which is dissconnect as it stays energizered on boot up)

    All game play lights and plays as it should.
    It cycles players and 5 balls.

    Bonus works and drop downs pop up.

    Any advice would help allot.

    Ive had all the boards off and inspected and tested on T points. Tests good. (Ill recheck its been a while)

    20181227_112704 (resized).jpg20181227_112704 (resized).jpg
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    #2 5 years ago
     
    PIP

    Quench

    Pinside member

    8y 114K 8,035

    There's 4 signals from the MPU board to the displays which tells them which number to display.
    On the MPU board schematic, these 4 signals marked D0, D1, D2 and D3 come off connector J1 pins 25, 26, 27 and 28 respectively.
    In the table below I've listed all 16 binary combinations of these 4 signals (0=0 volts, 1=5 volts) which determine the display number.
    Since you're only seeing numbers 2, 3, 6 and 7 we can see that the displays are never seeing signal D1 go to zero volts.
    It means you likely have a bad connection on that signal and it's probably at the MPU board terminal pin 26 of connector J1.
    You'll have to inspect the MPU board J1 pin header for corrosion and remove the wire terminal from pin 26 of the connector housing and replace it.

    DDDD
    3210 .. Digit
    =============
    0000 .. 0
    0001 .. 1
    0010 .. 2
    0011 .. 3
    0100 .. 4
    0101 .. 5
    0110 .. 6
    0111 .. 7
    1000 .. 8
    1001 .. 9
    1010 .. blank
    1011 .. blank
    1100 .. blank
    1101 .. blank
    1110 .. blank
    1111 .. blank

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    #3 5 years ago
     
    KK

    creepykenny

    Pinside member

    US Meridian, ID

    9y 33,800 198

    quench, good stuff i like it!

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    #4 5 years ago
    OP
     
    BMX

    lowkeyfilms

    Inactive member

    US Clearwater, FL

    8y 19,150 22 5 7

    Quench I cannot thank you enough for taking the time to spell that out for me. I have a schematic but never would have figured that out. I hope santa was good to you

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