Quoted from mbwalker:Maybe a leaky MOSFET or transistor allowing some current to always run thru it, but not enough to really turn on. Or the device that drives the MOSFET or transistor is leaky, biasing on the MOSFET or transistor (didn't look at the schematic to see which is used).
Take a voltmeter, and go across the coil and measure the voltage.
Bally flippers aren't transistor controlled. Just the relay is that provides a ground path during gameplay/non-tilted.
For the OP if the flipper is getting hot in idle mode you have it wired incorrectly, the lower secondary EOS that is normally open provides the solenoid + voltage to the upper flipper a split second after the lower flipper operates. The theory was that if you flip 2 at once, at exactly the same moment, it will put stress on the flipper circuit (IME it doesn't make a whit of difference, I usually have my bally/stern dual flipper games with the secondary EOS adjusted closed so they both activate at the same time.)
You've got something grounding out the coil/sneak voltage.
Walnut Creek, CA
