(Topic ID: 230582)

Alltek Bally displays always show no leftmost digit for certain player

By swampwiz

5 years ago



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  • 7 posts
  • 3 Pinsiders participating
  • Latest reply 5 years ago by swampwiz
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    #1 5 years ago

    This is the early standard for Bally (title specifically "Supersonic) with an Alltek MPU. I have a pair of display modules that work fine when installed at a certain player position (A), but do not have the leftmost digit in another player position (B). This would seem to indicate that there is no problem with these modules, but rather with the wiring or MPU for position B. (The MPU is an Alltek one.)

    I've read the article by Steve Kulpa on these displays, but it address problems with the display modules, not with problems that exist on any display module installed at a particular player position. I've taken a look at the schematic, and it seems that the only different line going to each display is the #6 pin - and I've successfully tested continuity from the boards (i.e., the MPU & display).

    I've also done the memory clear procedure (i.e., set the title dipswitches to 01111111, then power up and watch LED #4 flicker off & on every second), but the problem still persists.

    #3 5 years ago

    Why would the repinning work? I've already determined that there is continuity between the boards using that pin.

    #5 5 years ago
    Quoted from Billc479:

    It's possible the pin is corroded on the inside and not making good contact with the connector on the display unit. Also, reflowing the solder on the connector of the display unit is a good idea since the harness flexes every time the backbox door is opened, and that flex transmits force to the connector, causing the connection to break. You might read continuity while the door is open, but once the door is closed, the flexing may have caused a loss of continuity. Reflow the connector first before chasing after the pin.

    The check of the digits happens when the door is open.

    1 week later
    #7 5 years ago
    Quoted from Billc479:

    It's possible the pin is corroded on the inside and not making good contact with the connector on the display unit. Also, reflowing the solder on the connector of the display unit is a good idea since the harness flexes every time the backbox door is opened, and that flex transmits force to the connector, causing the connection to break. You might read continuity while the door is open, but once the door is closed, the flexing may have caused a loss of continuity. Reflow the connector first before chasing after the pin.

    The check of the digits happens when the door is open.

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