(Topic ID: 223569)

Bally switch matrix woes.

By Moto_bone

5 years ago



Topic Stats

  • 7 posts
  • 3 Pinsiders participating
  • Latest reply 5 years ago by barakandl
  • Topic is favorited by 1 Pinsider

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#1 5 years ago

Hello everyone.

I've got a phantom switch closure issue that I just can't seem to comprehend. This is on a granny and the Gators game.

I can't use the rectangle method to solve this one because it's doing something I've never seen.

Switch test shoes 0 initially. I'm having a phantom closure on switch 3 which is a rollover.

The game will randomly show switch 3 closed and then go back to 0.

To make things a little more odd. If I hit switch 19 which is a roll under on that same return. It will trigger 3, 11, 19, 27, and 35 as momentarily closing and then it usually returns to showing 3 in closed again.

Anyone ever seen something like this?

#2 5 years ago

Coincidentally, switch 3, 19 and 35 are the only switches that exist in that matrix. Switch 11 and 27 don't exist.

#3 5 years ago

Switch 3 keeps closing. As soon as I go in to switch test. 3 is active but it's not. I've replaced the diode with 1n4148 and also tried a 1n4004. Replaced the diode on switch 35 and also 19. Switch 19 causes all sorts of random switch closures though.

I've also shotgun repaired the 6821's. No luck.

Anyone?

#5 5 years ago
Quoted from Nokoro:

Perhaps a short to ground?
I had some weird behavior with switches all firing in the same column on my Special Force. Turned out I was leaning on the rail at the same time I was pressing the metal rivet on the switch with my finger creating my own short to ground.

Well kind of...

I did solve this and it was an extremely weird problem that I still can't quite understand but I'm going to press the "I believe" button.

I clear coated this playfield late last night and then wet sanded it after work today. Put it back together and then had this problem. Apparently the moisture from we sanding is giving me a ground through the playfield.

If I touched the switch and then put my fingers on various screws on the playfield- I was seeing random switch closures.

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