Grand Prix
Williams, 1976My Grand Prix was gone through pretty recently but I'm starting to see an issue where the left bonus countdown no longer resets to 5K, and subsequent plays seem to prevent the spinner from advancing the bonus. The unit moves freely and the bonus collect relay gets to the end, but its supposed to advance forward 1 tick after collecting the bonus, right? I've enclosed video showing what's going on.
Quoted from HowardR:Does this happen when the ball drains, or when it goes in the left hole?
Both
Since the Left Bonus unit doesn't advance to zero when the ball drains,
Inspect and diagnose this circuit with Alligator clip jumper wires
pasted_image (resized).png
https://pinside.com/pinball/forum/topic/gottlieb-big-shot-repair#post-6305153
http://www.planetimming.com/Pinball/troubleshooting/EM%20Troubleshooting.pdf
http://www.pinrepair.com/em/index3.htm#features
Example of a pinsider actually doing this https://pinside.com/pinball/forum/topic/red-baron-tech-question#post-5858156
I agree with HowardR on the red path for advancing when ball drains. Check score motor cam 2 switch A with black-orange & black-green wires connected.
For the left hole bonus advance after zero, check the left hole switch with black-yellow & black-green wires connected.
Clean, inspect, and adjust switches if needed.
Make sure the assembly is square. Align the square brown boards so the swiped contacts are on the right bonus score.
You can move them with your hands.
It is common to set the pf down on this part and it gets out of alignment.
It is always the left score because that’s the best be the tests in the lockdown bar when working on the pf.
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Boulder, CO