(Topic ID: 274307)

*SOLVED* Gottlieb 300 sometimes doesn’t advance player and ball count

By Zog

2 years ago

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  • 6 posts
  • 2 Pinsiders participating
  • Latest reply 2 years ago by Zog
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300 Player Unit (resized).jpg
8BC0E790-DE03-4276-8897-55CF81B1F62E (resized).jpeg

#1 2 years ago

I’m working on a Gottlieb 300 for a friend. It had sat for years and had plenty of issues, as you can imagine.

I’ve got it working nearly perfectly, except about once a game it doesn’t advance the player or ball count. I’ve cleaned the stepper unit.

The owner is happy with the way it is, but I’d prefer to have it working perfectly before he takes it.

What exactly sends the signal to the stepper unit? Is it the score motor? If so, does anyone know what switch?

Thanks in advance.

8BC0E790-DE03-4276-8897-55CF81B1F62E (resized).jpeg

#2 2 years ago

The Add Player Unit circuit has a lot going on and is often discussed here. Here is the 300 circuit:
300 Player Unit (resized).jpg
Can you elaborate on when it fails to advance? Any particular ball or player? Any number of players on a game? The better you can characterize the issue the more you can eliminate from this schematic.


#3 2 years ago

It seems very random. No particular player or ball.

Looks like 1A controls it?

#4 2 years ago

The Score Motor 1A switch has to close for the Player Unit to advance, but so do a whole bunch of other switches. If it happens during a 1 player game we can eliminate the P2G, P3G and P4G circuits at the bottom. That still leaves the Score Motor 2C switch and switches on the U and P relays for example that could be part of the problem or any of the normally closed switches if they're intermittent.

#5 2 years ago

Thanks! I’ll check those switches and let you know.

#6 2 years ago

The switch at 1A was misaligned. I also gave the othet switches a quick cleaning.

Thanks MarkG! That completely solved the issue!

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