(Topic ID: 177973)

Tech: Help with a system 1 MPU - locked on coils

By action76

4 years ago

Topic Stats

  • 6 posts
  • 3 Pinsiders participating
  • Latest reply 4 years ago by action76
  • Topic is favorited by 2 Pinsiders


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#1 4 years ago

Got a Genie I am working on that had a board with slight battery damage. I cleaned the board and neutralized the alkaline leakage. After replacing the board, it was booting and playing. After leaving it on a while, say 30 minutes, I noticed that the outhole and the kickout solenoid was locked on. I tested all the transistors on the driver board and they tested ok. If I unplug the connector between the MPU and driver board and power on the machine, the solenoids do not lock on. This tells me (I think) that the problem is with the MPU board? Could anyone help me figure out where to look for this problem? I am hoping it is not the U4 spider chip and can be fixed. Any help would be greatly appreciated.

#2 4 years ago

It may also need that harness between CPU and Driver rebuilt.

#3 4 years ago
Quoted from cody_chunn:

It may also need that harness between CPU and Driver rebuilt.

That could be true, although, the way it was working just fine and then all of a sudden these two coils decided to lock on makes me think a chip or something failed. I have disconnected and reconnected the harness several times, but it always locks on now, unless I leave it unplugged.

#4 4 years ago

Have you done the recommend System 1 ground mods? Locked on coils are one of the symptoms of poor grounds.

#5 4 years ago

I have not done the ground mods permanently yet, but I did do all the grounds temporarily with alligator clip jumpers just to eliminate that from being a possible cause.

#6 4 years ago

Anyone know any tests I can do to narrow down the culprit?

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