Quoted from cottonm4:
It started out by teasing me. And then it got a little more aggressive. But it was not 100% toying with me. Yesterday, it finally said "replace me".
I'm talking about a flipper coil. The flipper starting sticking in the up position. I'd turn off the cabinet switch and the flipper would drop. I would turn the pin back on and all would be working fine. And then, eventually, it would stick in the up position again. I could turn the pin off and all would be well for awhile.
Yesterday, it shorted all the way. I finally had to replace it.
I have not ran any ohmmeter tests, yet.
What causes a flipper coil to just decide to give it up?
What is the most likely culprit?
Is it the primary coil shorting out?
Or is it the secondary hold coil doing me dirty?
Or has a diode gone bad?
Quoted from vec-tor:
What I have found, is that magnetism is the culprit.
Once the back coil stop has impurities cross the brass bushing, the hole bracket
becomes one big magnet. Eddy current happens.
1) clean coil stop.
1a) tap coil stop with a hammer to breakup impurities.
1b) test coil stop
1c) if flipper assembly still hangs... replace coil stop assembly
1d) if skilled, can fabricate a new stop to replace old stop.
Vec-Tor, I must thank you for offering this info. I replaced my coil and the sticking flipper issue went away---for a few games. A couple of days ago this flipper started sticking in the up position again. As soon as I pressed the credit button the flipper went into "locked up" position. I mean it was locked hard; I could not manually break the lock.
So, I replaced the plunger and coil stop. Like magic. No more problems. If you had not given this info. I would still be racking my brain with this issue.
Interesting in that the end of the plunger and the the button on the coil stop have matching marks that looks like they were trying to weld theirselves together. I don't think I can get a decent picture of these marks.
EDIT: Well, the problem came back again. I have a new solenoid coil, new plunger, and a new coil stop. I was playing ng a few highly spirited games and the flipper locked up again. Turn the pin off and back on. Flipper locks up. Finally I disconnected the flipper wire connector on the SDU to disable the flippers. I fired the pin up and hot plugged the flipper wire connector at the SDU. The flipper returned to behaving normally. I don't know for how long it will behave.
I'll keep you all posted.