I need some help to figure out what went wrong with my game. It has been working fine but recently noticed the right flipper got very weak after only a few plays. The coil gets very hot when playing the game but will cool down when not flipping. I am not holding the flipper up or anything either. I dont feel any mechanical friction moving the plunger by hand. I put a volt meter on each side of the coil power and got the same readings as the left side which has no problem or over heating? I think it was about 70VDC(same as left side). It meas. about 7 ohms across the coil which also matches the left side. I tested all flipper switch functions in the sw. test including E.O.S. and they look normal. Any ideas?

It moves very freely above or below and has proper clearance.

I really dont think its the EOS but I will recheck tonight.

That is interesting. I wonder what the function of the EOS switch does on Sterns? I noticed the upper right flipper does not even have one but both lowers do. How can you tell if its really going into low power hold mode?

Its looking like my problem is probably the same as yours. The EOS appeared to be completely normal in switch test. However when I checked the switches with power to the coils I noticed the right flipper EOS would open occasionally by flipping the left flipper? I adjusted the EOS to close harder(right side) and no longer see the intermittent opens while flipping the left flipper. I think it has probably been doing this the whole time. The coil still gets hot after a few plays and is very weak but measures the same as the left coil(about 7ohms). I talked with Stern support and they are sending me a new right side coil. We are assuming the coil is now defective even though it has no friction or visible signs of damage.
If the improper adjustment of the right side EOS led to the coil failure there is still one thing I don't understand. If the coil was getting pulses of high voltage due to intermittent EOS opens(from improper EOS adjustment) then why didnt I ever see the right flipper flip when I was not expecting it?

Tried the new coil last nite, no luck. Exact same problem. Looks like the problem must be on the I/O power board. I am guessing that the holding circuit is not pulsing the high power correctly for some reason so the coil gets hot. After researching this more I found out Stern uses 50VDC to both flip and hold the flipper up. The initial pulse is 40msec followed by a 1msec pulse every 12msec if the flipper button is held in. This pulsing allows them to use 50VDC to hold the flipper without generating heat in the coil. I think something with the power pulsing circuit has failed. It would take an oscilliscope to see all this though which I do not have.