Hey everyone,

Game was weird for awhile, trying to hunt down a short and not really finding any - High level stuff, like are things isolated.

The issue final presented it self consistently:
> Left Flipper = Few Flashers, one special solenoid, and sometimes the ball kickers would twitch.
> And then either reset or freeze the game after 3 -12 flips.

Switch, or solenoid tests would not trigger any issues. PSU voltages remained in spec.

Inspected the wiring, gave everything a gentle wiggle, and the capacitor detached on one side. 3/8 into it's sleeve was a break.
Removed sleeve, tested it, and seemed good.

Held it contact point (wearing gloves) on the leaf. . . hit the flipper and the twitches went away.
Solder back on and so far game is behaving. . . for now.

I know this is supposed to only prevent arcing, but has any else experienced this?
Have no clue how this could have stopped the issue; Have been reading about MPUs reading the state of switches and needing a capacitor to do so. . . .

There are no diodes on the coils or in the documentation for the flippers solenoids.
Still very new to this stuff, so any insight is appreciated.

Riverboat Gambler

Ah, OK and doh! Was looking at the wrong diagrams; and not familiar with pinwiki (I will familiarize myself). Rooky mistake! Thank you!

I didn't see any diodes on either flipper; I was expecting these to be on the solder points for the coil - like many other games I've seen. I will attempt to check again.

Found the diodes . . . It helps if you look at both ends. Feel very "special" now.

Right flipper has two, continuity is good along the legs, nothing loose. Coil has 4-5 ohms resistance.

Left flipper has one, and while checking continuity it moved right at the via. Coil has 4-5 ohms resistance.

Based on the diagram, I should have two on each, correct?

Any recommended brand diodes?

Thank you.
Diodes are on the way.

I'll look for the missing one next time I'm in there.
Perhaps I received it with out. . . I didn't know any better to look.

I "think" I have a better understating of flipper mechanism going through this exercise; Didn't occur to me or could not find any cause and effect experiences where capacitor and diodes were missing; but I suspected it could have been related "maybe" - just no clue how or why.

Could not find a theory of operation sort of material, at least broken down to the point it's obvious that is what the material is about. If anyone has anything like that - preferably with diagrams and/or video - please share.

I would like to thank everyone for the help and direction thus far; As crass and green to this as I am.

It'll be a couple days to get the parts and I'll post the results.

Right. To elaborate, I meant as far as the EMF-pulse stuff. Like missing diodes and/or caps make other things tweak out.
I was look up thing like "flipper causes pop bumper to activate" and "flipper activates other solenoid" things like that. It wasn't until the game reset or froze that it was easier to narrow things down: "flipper causes game reset" had more hits and discernable relation to what I was experiencing.

I found these:
https://homepinballrepair.com/how-serial-flippers-work-in-early-ss-and-em-pinball-machines/
https://homepinballrepair.com/how-parallel-flippers-work-in-newer-ss-pinball-machines/

Seems to explain things at my level.

Diodes are in and issue appears resolved.

Thanks again for all the help.