Picked up an 'as is' twilight zone the other week, its fairly solid, but previous owner had added a lot of mods (alligatr clips everywhere!) and was pretty dirty playfield wise. It powered up when i viewed it and was not on legs, so i just flipped it once and did the deal.

Got it home and there was a multitude of issues - firstly it wouldn't even boot after transport. Redid connectors and pins J101, J102 and replaced MPU (old battery damage), and some of the 12V plugs J118 etc, then got it booting and playing. However ALL the flippers are really weak - not that weak that its like only the hold coil is working, but weak enough that its almost impossible to get up a ramp.

I have verified all EOS only activate right at the end of stroke. All flippers/plungers move freely and have inspected some of them and plunger and link are in good condition, along with coil stop with no burring or wear. I have also cleaned the cabinet opto switches with windex - all of the above with no change.

So it leads me to think its a power issue. The flippers have 50V going to all 3 lugs, however all other coils have 73V. The power driver board at J104 has 50VAC going to fliptronics board. The fliptronics board had been replaced by previous owner with a rottendog one. Is it normal that the flippers have only 50V rather than around 70V going ot them, and would this cause all flippers to be weak?

Any other suggestions?

So do you think it is more likely a fliptronics board issue (will swap it when i get home), or a power driver board issue - if power driver board, will have to look at the diagram to work out where that supply comes from.

OK, put an original fliptronics board in from BSD, and flippers are now back to nice and strong!

Be nice to try and work out the source of the problem on the rottendog fliptronics board. The 4 diodes (no bridge) test OK in circuit and fuses have around 0.5 ohms resistance.