Hi everyone! Recently got my first machine -- a blackwater 100. Fun game! It has 5 flippers- 2 main, 2 upper, and 1 down at the bottom, backwards. Played it for about an hour and suddenly went from 5 flippers to 2. First, the upper left flipper got stuck in the up position and I pushed it back down with my hand (and it stayed down). The upper flipper and that backward lower flipper no longer responded. Then the left main flipper stopped responding shortly thereafter.
I've never looked under a pinball machine field before. I pulled up the play field and the secondary end of stroke switch on the main left flipper (the one that triggers the next flipper) had a completely melted plastic spacer. So the flipper would open the eos switch, but due to no spacer the secondary eos switch would not close because nothing was pushing against it. That would cause the 2nd and 3rd flipper to stop, but why the main flipper? Because the eos switch would open and the metal would get caught on the melted plastic blob, keeping it open, and preventing the flipper from firing more than once. Replacing the secondary eos switch with a fresh one fixed it since there was nothing to get caught on. During installation I left the new switch unconnected to the next flipper so I could verify the flipper worked as expected. Seems ok..
Ok so we're up to 3/5 flippers. I turned my attention to the 2nd flipper--this is the top upper flipper. The paper around the coil was dark. The flipper plunger would not move freely in and out of the coil. I guess the plastic sleeve on the inside melted and so when the flipper was stuck up, it was because it was physically stuck in there. I replaced the coil and sleeve. The plunger could now move freely. I reattached the main flipper's secondary eos switch to this newly-rebuilt flipper and my flipper count went back to 5. I did not dare hit that flipper button more than a few times to verify everything's connected--there is still the problem of why it overheated and melted everything.
I used an infrared thermometer to track the temperature of the coil. When I used the flipper, and especially when I held it down, the new flipper coil would build temperature. Whereas a working flipper stayed a cool 60 degrees no matter how much I hit or held the button, this coil got up to 160 degrees after a few minutes of button mashing before I shut off the machine. I also heard a decent buzz that I didn't hear on the right side. I compared the wiring of the coil to the others on the table (there was a wide selection for comparison--remember the bit about there being 5?) and determined that it was wired backward. The bundle of 3 wires was going into the center, whereas on all other flippers it was going to the banded-diode side. So I swapped it. Unofficially, I would say the temperature now rises less quickly (I played a few balls and the temp was 90 when I shut it off). But it does rise still. And there is no more loud buzzing, but I feel like still a soft buzzing. What is my next thing to check?