(Topic ID: 265962)

WPC: Row 2 has 73.5v in Switch Matrix - Power Driver Board Issue

By BroMike

3 years ago



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  • 2 Pinsiders participating
  • Latest reply 3 years ago by pinmike
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#1 3 years ago

Hi all, my Getaway has been having an issue with Opto 2 in the supercharger and I finally figured out it's because Row 2 is showing 73.5v instead of 11.5-12v. I had been focusing on the MPU and Accelerator Board (swapped the LM339's) but after disconnecting the ribbon cable between the MPU and Power Driver Board, the voltage was normal. I swapped out the Power Driver Board from my Fish Tales and everything works.

Any ideas what would be causing the high voltage issue? It looks like there are a 2 - 4N25 chips in the circuit so I'm guessing one or both went bad? I tested the resistors with my DMM and they seem to be fine. Do people socket 4N25's or solder them directly on the board. The C2 capacitor is also showing signs of leakage which I heard causes some switch matrix issues. Just wanted to get some more opinions if anything else could be causing this issue.

Thanks,
Mike

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#2 3 years ago

If the C2 capacitor is leaking that’s the main suspect and to test a resistor you must remove one one off the board.But C2 is the culprit

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