(Topic ID: 249256)

Firepower - Displays start on 222222

By RXTbone

2 years ago


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  • 12 posts
  • 4 Pinsiders participating
  • Latest reply 2 years ago by RXTbone
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    #1 2 years ago

    Game functioned properly for a period of time - now it's sits off for several months, then someone fires it up to play a game... Batteries are fresh. Upon startup, players 1 and 2 display 000000, and function properly during game play. Player 3 and 4 will start at 222222. Game play will change the numbers, but none of them are right.

    Of note: First issue with display 3 and 4 was that they originally displayed 333333. I cleaned the door/diagnostics connector on the MPU board servicing another issue with the door - and displays 3 and 4 went from 333333 from 222222.

    Any suggestion for where to start trouble shooting would be appreciated.

    #2 2 years ago

    put the game in display test and see what the count is and if numbers are certain displays are skipped and others repeated.

    I think you are going to have a connector issue at the MPU on 9 pin plugs across the top of the MPU.

    #3 2 years ago

    Any ideas why re-seating the door/diagnostics plug would switch the 3d and 4th player from 333333 to 222222?

    #4 2 years ago
    Quoted from RXTbone:

    Any ideas why re-seating the door/diagnostics plug would switch the 3d and 4th player from 333333 to 222222?

    because that plug is nearby the display digit count encoded data plugs and it made the board flex breaking/opening an intermittent connection. Probably broken solder joints on the connector pins. Take a picture of the back of the MPU board and we can probably see the bad solder.

    There is 4 bits from the MPU that get decoded by a 4543 chip to form a number. Here is the display decoder chip truth table. Note how bit B can change all zeros (what it should be) to all 2's. If B and A are wrong all zeros can turn to all 3's

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    Check this connector with the orange arrow pointing at it. Probably where the issue is.
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    #5 2 years ago

    Thank you for taking the time to provide such detailed info. I will check this out and follow-up. Thanks again!

    #6 2 years ago

    I tested the posts and solder joints this evening, and everything tested out OK. I did unplug the master display connection and the displays all went to 000000. Plugged it back in and 3 and 4 went to 222222 - then actually changed to 333333 before my eyes, untouched. Is this a chip fault somewhere?

    #7 2 years ago
    Quoted from RXTbone:

    Game functioned properly for a period of time - now it's sits off for several months, then someone fires it up to play a game... Batteries are fresh. Upon startup, players 1 and 2 display 000000, and function properly during game play. Player 3 and 4 will start at 222222. Game play will change the numbers, but none of them are right.
    Of note: First issue with display 3 and 4 was that they originally displayed 333333. I cleaned the door/diagnostics connector on the MPU board servicing another issue with the door - and displays 3 and 4 went from 333333 from 222222.
    Any suggestion for where to start trouble shooting would be appreciated.

    Suggest Re seating the cables on the Master Display Board.

    MD (resized).jpg
    #8 2 years ago

    Thank you for the help - already did a swap, between 2 and 3. Player 2 went to 333333, and 3 zeroed out. I think this is back to a chip identified as IC18/6820. But - this is beyond my testing abilities or knowledge.

    #9 2 years ago
    Quoted from RXTbone:

    Thank you for the help - already did a swap, between 2 and 3. Player 2 went to 333333, and 3 zeroed out. I think this is back to a chip identified as IC18/6820. But - this is beyond my testing abilities or knowledge.

    Good chance PIA is functions as its able to produce correct output at player 1 and player 2 displays good segment data, further distribution of signals is done on the Master display board after IC 6 which could be partially working and not throwing correct strobe timing at P3 and P4
    Before changing the PIA IC 18 or decoder IC 6 or Master display, the signals need to be checked for full presence at IJ5 , IJ6 and, IJ7 and if a signal(s) is missing will need to be traced to the source by isolation using a logic probe.

    #10 2 years ago

    Thank you for the reply! Is the forum allowed to recommend someone to work on boards? Been several years since I had board work done. Thanks!

    #11 2 years ago

    Chris Hibler is a well known tech here that can service your boards - http://chrishiblerpinball.com/.

    I've also used the Coin-Op Cauldron numerous times and they've always done good work. Good luck!

    #12 2 years ago

    Awesome - thanks for everyone's help! Always appreciate a responsive helpful forum.

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