(Topic ID: 260709)

1986 Bally Closed Switch Issue

By PinballGurus

1 year ago

Topic Stats

  • 3 posts
  • 3 Pinsiders participating
  • Latest reply 1 year ago by frunch
  • No one calls this topic a favorite


Linked Games

#1 1 year ago

I’m having an issue with my Special Force where it is reporting closed switches I know are open; when I unplug the switch connector from the board the problem resolved so I’m relatively certain it’s not an issue with the board, but the playfield. Has anyone else ever experienced this issue?

Rocket K
Rocket E (not sure)
Left sling
Outhole right
Outhole middle
Outhole left
Bomb B
Load Bombs

Inline DT Bot

#2 1 year ago

Could be the wiring is intermittent/pinched wire from playfield when being lifted up and down.The male header pins on the board might need a fresh reflow of solder or connector is not making full contact to male header pins.
If it happens again just go over what I stated above

#3 1 year ago

Looking at the schematic for this game, there are lots of switches on the switch matrix that use 0.5uf ceramic caps. If you cut a leg off each cap that's attached to a switch, you may find the problem goes away. These caps have a tendency to sometimes short internally when they got bad, which can screw with the switch matrix. They're there to help the mpu detect fast switch closures, so it's recommended to replace them if they're bad.

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