(Topic ID: 251279)

Doctor Who Repair Manual/Site/Advice

By mwrussel

4 years ago



Topic Stats

  • 10 posts
  • 4 Pinsiders participating
  • Latest reply 4 years ago by mwrussel
  • Topic is favorited by 1 Pinsider

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    #1 4 years ago

    I have a Doctor Who pinball that I purchased in pretty rough condition about 10 years ago. As an amatuer, I was able to replace enough boards and fix it up enough to get it playing pretty well. A few of the optos didn't register, but it was very playable. Over the last 6 months, it started making beeps like the coin door switches were firing during the game. Wiggling a few wires around seemed to get it to stop. About a week ago it started making the noises again, then the playfield started raising/lowering to random positions, lots of errors were showing up on diagnostics. The volume suddenly went to maximum and i would not turn down using the volume control. I noticed a little corrosion below the battery bank, and thought maybe that had caused it. I ordered a rottendog MPU replacement board, but it didn't fix any of the problems and now the game just lights up, make a small amount of playfield movement then freezes. No DMD activity.......so, I'm interested in just starting at the beginning and trying to work my way through the machine slowly and check it part by part in a methodical manner. Any advice on resources would be greatly appreciated.

    #2 4 years ago
    Quoted from mwrussel:

    Any advice on resources would be greatly appreciated.

    I'd start with the coin door diagnostic buttons. Are they clean, work when tested with a meter to their backs ? The metal prongs off of each switch not shorting to metal behind them ? Flap on coin door fully depressing the memory protect switch ?

    LTG : )

    #4 4 years ago

    Sounds like you had some possible minor issues starting with the coin door buttons as LTG points out and possibly an issue with the playfield glass switch (top left corner) or secondary door switch which will warn the crap out of you due to the danger of the moving playfield. As you were close with the original board I personally would go Back to that point and loose the Rottendog board as I personally have not had much luck with those. Put it back as it was and start posting 1 issue at a time with pics if possible. Many will help you through this but you have to tackle this one step at a time. Just my thoughts and wish you luck. Great game love ours!

    #5 4 years ago

    Thank you all. I'll replace the old board and start at the coin door and will post pics.

    #6 4 years ago
    Quoted from mwrussel:

    Thank you all. I'll replace the old board and start at the coin door and will post pics.

    Start at the connectors to CPU. They may have corrosion.

    #7 4 years ago

    Initial steps, before I check the coin door....when the I power on the pin, the CPU board LEDs turn on....I hear a few popping noises from the speakers, but no lights or movement anymore. I swapped in the old board and it behaved the same way, so I put the new board without the corrosion below the battery terminals back in with all the chips transferred.

    I checked the power to the board, It appears all is normal there. At J210, I've getting 12V and pins 6 and 7, 5V and pins 4 and 5, 0 V at pin 3...all versus pin 1 which I believe is ground.

    The LED's on light up do the following...

    D19 (top when installed) lights up stays on
    D20 off
    D21 lights us stays on

    Also, I checked all the chips I put in to make sure all the pins did not look damaged. The Dr Who Rom and the processor appeared to be in good shape/undamaged. The new ACIS chip which was sent also appeared undamaged when I installed it.. I even zoomed in on the pins with my phone to make sure none were bent. I installed them in the same orientation that they had on the old board.

    Thoughts?

    #8 4 years ago

    Update....both MPU boards old and new are exhibiting the same LED behavior. According to my manual, the LED pattern in the previous post indicates power to the CPU but the CPU is processing improperly. Have two ASIC chips, I examined them both for any missing pins/chips/cracks. All pins on both chips are present, if one was slightly askew, I straigtened it out before replacing it the socket. The socket itself looks good and undamaged on both boards. I get the same behavior regardless of the chip board combo. The other unique chips would be the ROM chip and the Processor. I only have one of each and both appear to be undamaged visually.
    I believe all chips on the boards are in the proper orientation, (the little notches aligned, and the dot on the ASIC, aligned to the right where the arrow inside the socket points, also how it was before removal with tool). If I'm doing it wrong, what would happen if a chip was placed incorrectly?

    #9 4 years ago

    I unplugged the power to the MPU (J210) and powered up the machine. All GI came on, I got a single bong. The DMD light up with random pixelations that were static. I soon as I plug J210 back in, all lights, DMD go off with the same two MPU leds lit and a repetitive sounds of quick "dots" like its resetting. Could it be currently stuck in a reset on the MPU?

    #10 4 years ago

    eyeamred2u Yelobird LTG
    Don't if you followed this thread, but I believe all is well again, or at least 95% well. A little confession, the reason I couldn't get the CPU's up and running again was that I connected a long ribbon cable upside down, once corrected, everything came back to life. The old CPU board appears to have been the problem. The corrosion from the batteries was mostly on two chips, one of which involved the coin door operation. The new board seems to have resolved that. With all my mistakes, I apparently blew two of the fuses, but once replaced everything came back to life. I don't know much about how to fix these things, but it sure is fun learning and I appreciate your ideas, they got me looking in a more methodical manner that helped me find the problems.....now to get three of the miniplayfield optos working for the first time..thanks again!

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