Usually it's more involved, but I have seen coils where it shorted internally with chips in the insulation.

It could have been also a dirty flipper button opto that caused the coil getting hot and eventually getting short.

Flaky flipper opto boards definitely can happen ... The flipper opto "pulses" the signal so the coil rapidly turns on/off (many times a second) and gets really hot. I had this happen once. Usually cleaning won't fix it, it's a bad opto. Cleaning the Optos can help with weak flippers though.

I also had a bad flipper chip in my TOTAN (also wpc95) which would do the same thing, the coils would get very hot during an extended game.

Another thing could be a faulty flipper circuit so that the circuitry isn't changing to holding voltage when the flipper is held up. If you played the 20 minute game without a lot of holding (ie normal quick flips) this wouldn't show up so much.

I recently bought a sorcerer where the EOS was wired completely wrong, in such a way the coil was getting full voltage all the time. The previous owner had played it like that for a year with no visible problems. One of his buddies came around and was holding a ball on the flipper for a while during multiball and it completely melted from the heat.

rd

check mechanically to ensure the EOS switch is functioning. Also check switch matrix to ensure EOS functions.

Yep. As Vid said, maybe just a bad coil, but I've not encountered that myself.

I'd play a 5 minute game with a heap of cradling, and see if the coils are hot after that. They shouldn't be.

rd

I have to replace one tonight. When too much cradling was done the flipper started sticking up. Saturday night I pulled the flipper mech apart expecting a mushroomed / magnetized coil stop but found the coil sleeve was very difficult to remove. So it seem some insulation is cracked inside the coil causing a short. Not enough to blow a fuse, but shortens the winding enough to generate some heat.

Òh, that is very common. The coil has seen some heat over the years, and the sleeve is hard to get out because the centre of the coil is distorted. Time for a new coil.

However coils spontaneously combusting is pretty rare.

rd

In switch test, push the flippers forward (one at a time) and verify that the EOS switch is closed before playing a game.

If you still have the old coil, can you check the diode located between the 'Hold' and Center lug by cutting it loose and measure continuity. In picture D1
When this diode has a short, it could give similar results.

just curious

coil_short_diode_(resized).PNG

I just had a bad left coil on my AFM. Started to stutter when pushing the flipper button.

Checked basics first. Then removed the coil to look it over better. Came apart in the slinky effect. The stuttering was an internal thing, and I'm sure like yours would have shorted/melted soon.

LTG : )™

For what it's worth, a bad eos switch will not melt a flipper coil on a wpc95 game because the software will compensate for this failure. Hope you got lucky and it's just a bad coil!