About to embark on my first pinball repair...

ChaosJohn

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I've fixed a bunch of arcade machines, but I'm about to do my first pinball repair. Which has me a little nervous. Not really any moving parts on an arcade game, so a lot less to go wrong.

So the problem is a stuck flipper on my Pin-Bot. It started smoking at a party awhile back, and a friend turned it off and unplugged it and told me about it. I had never diagnosed pin problems before, so it took me awhile to work up the courage to even open it up and take a look. A friend who's more pinball savvy than me came over and walked me through a fairly easy diagnosis. The flipper fuse was blown. We looked at the flipper coils and one of them was clearly locked up. Problem found.

I've bought the replacement coil, and I also bought a flipper rebuild kit, and I'm probably going to dive into doing the actual repair this weekend. I've done a little bit of reading, so I'm a newb with a little knowledge, but I thought I'd check these forums to see if I could get any extra advice.

I'm planning on replacing the coil, rebuilding the flipper, and replacing the blown fuse.

Is there more I should do? Should I test the transistors that drive the solenoid? Any other things you think I should check before I fire it up?

It was working perfectly before the flipper went out, but it has been sitting for almost a year, if that makes a difference.

Thanks in advance for any advice.
 
We looked at the flipper coils and one of them was clearly locked up. Problem found.

Found, yes. But you already knew that. Next you need to determine why that coil locked on. The coil itself didn't cause the problem. I would suspect the cabinet switch on that side stuck closed. Possibly because one of the legs on the capacitor on that coil broke off and the spark between the contacts eventually caused them to melt together.

If that's the case the EOS should still have prevented it from burning up right away but even the hold-in winding could cause a meltdown if left on indefinitely. I would check the EOS switches anyway.

I've bought the replacement coil, and I also bought a flipper rebuild kit, and I'm probably going to dive into doing the actual repair this weekend. I've done a little bit of reading, so I'm a newb with a little knowledge, but I thought I'd check these forums to see if I could get any extra advice.

I would check the capacitors and switch contact adjustment too.

Did you get kits for both sides? Unless the other side is really tight you should probably put kits in both sides. You don't want your flippers to be uneven. Assuming you need the kits at all. You might just need a new coil and sleeve for the melted side, replace the broken cap and file the switch contacts.

Ultimately you'll have to look at the flipper assemblies and determine what you really need.

Is there more I should do?

Yeah... fix what caused the problem in the first place :)

If you just throw a coil in there it will just stick on again.

Should I test the transistors that drive the solenoid?

There is no transistor that drives the flippers (on system 11). They're driven straight through the cabinet switches (through the flipper relay).
 
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pin bot

I would check the EOS switch for sure just to make sure it wasn't what caused the problem. The fuse went out to stop everything else from blowing. If your going to do the flipper rebuild I would make sure your doing both. You don't have to replace both coils but everything else would be a good idea. If you find one coil is stronger then go for broke and do both. pin bots are simple pins and most the time it's a EOS that goes bad. Trace your wiring and make sure you haven't got a short anywhere as well just to cover all the basics. I have worked on this pin a lot so if you need anymore help let me know.
 
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Before you go scratching your head and walk off confused, I believe the "OES" reference 2 posts up is really meant to say "EOS," which is an End-Of-Stroke switch. It is a leaf switch attached to the flipper bracket that is configured to open when the flipper is "up" so that a smaller amount of current can be used to hold the flipper up through a second winding in the flipper coil. (With the EOS closed, the flipper can use the full power of the larger coil winding to get a strong flipper stroke; once it is up, the EOS switch opens and effectively reduces power to the flipper to avoid overheating of the coil.)
 
Before you go scratching your head and walk off confused, I believe the "OES" reference 2 posts up is really meant to say "EOS," which is an End-Of-Stroke switch. It is a leaf switch attached to the flipper bracket that is configured to open when the flipper is "up" so that a smaller amount of current can be used to hold the flipper up through a second winding in the flipper coil. (With the EOS closed, the flipper can use the full power of the larger coil winding to get a strong flipper stroke; once it is up, the EOS switch opens and effectively reduces power to the flipper to avoid overheating of the coil.)

Whoops. Fixed.
 
Thanks for all the advice. I printed out the section of the document from pinrepair.com on rebuilding flippers and I'll give it a go.
 
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