I have just repaired a Judge Dredd pinball machine that had really many gremlins hidden
Acid leak and several bad components on the main board, Deadworld not spinning and loose gear in gearbox as well as one damaged gear, now set up with led's and all cleaned, seems like only issue now are the left flipper coil getting hot and weak in periods ( replaced with new )
while playing there are times it becomes weak , and by measuring the voltages it looks like from time to time it does not shut off the current trough the "Main" coil, and keeps running current trough both coils while holding.
But not fully as voltage flickers around 25v over the main coil and usually just for a short time , meaning this is a periodic failure and just a short time so a bit tricky to start measuring why on the flipper board.
Anyone seen the same symptoms before ?

Regards
Terje

Thanks , will test them it's just weird they work normal specially early in the game
Also expect they will measure all fine due to that.
will try and measure input signal at base to see if those are fine

I measured both at the same time using two Fluke's
Hold functions fine , but kick seems to some time keep voltage and current for a longer period that it should as well as sometime flickering and delivered 25v to the kicker coil while flipper is in hold mode
also seems to get worse after playing some time , think I need to see if this is coming from the prossesor or the TIP36 output
Possibly the opto couplers?

Seems the opto coupler is reacting slow and not fully pulling down the voltage , ending in slow reaction from the kicker circuit, ordered a new one to try out.

Seems confirmed after replacing the left flipper board those opto couplers are reacting earlier and coil so far after some test playing is all fine and normal heat