Got a big guns that is suddenly not firering a flipper, lower right. I rebuilt the lowers a few weeks ago and they worked perfectly after. I finally got around to rebuilding the uppers and replacing the flipper buttons the other day. I made may repairs and buttoned everything up and no lower right flipper. Tested for voltage and nothing. I was getting intermittent firing of the upper right during trying to figure out what went wrong. So I decided to replace the ceramic caps and double leaf switch. I tested the coil and discovered it was bad so I replaced it. Still no love. I checked for continuity from the leaf switch and coil and I have that. Pulled the MPU to reflow J19 but looked fine as pictured but did it anyway. Looking at the schematics I am trying to chase down the path from the mpu but I have no idea where 8j3 or 7p1 are. Also all the fusses I can fined tested as good.

What do I need to look at next?

Don't mind the hot glue. I "potted" a noisy inductor.

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Everything is plugged in correctly AFAIK. It is keyed and faces the same way as the others. Now on J19 the plug is split. Pins 1 & 2 are not connected to the rest. But I am confident that connector is correct. It was operating until the one flipper stopped. Didn't even have the back back open when doing the flippers.

So I made a trip to my electronic component supplier and picked up the 12 transistors in the flipper circuit. They didn't have the tip122 but an equivalent. Was thinking replacing the 6 of them and just the one 2N4401 on the affected flipper line. I got the relay as well but don't really want to replace that unless I have to. That's a lot of damn pins on a device. Or am I driving down the wrong hole?

Pins 2, 4, 6, & 11 on 5J12 have around 75volts.

Thanks guys. The diagram DumbAss posted of the circuit side by side helped. Guess I didn't look far enough in the manual to see it. Corroded wire where someone nicked the wire. I must have moved something just right doing the rebuilds. Saved me some unnecessary soldering on the MPU. Now I have start to a collection of spare parts.