Mr. & Mrs. Pac-Man problems, still…

To retrace steps in case this helps diagnose the issue: I had the game playing fine. An issue arose where the upper flipper was only firing every now and then, instead of with every hit of the right flipper button, so, I replaced the very-decayed-looking EOS switch stack at the right flipper, thinking there was a connection issue.

After that, though, the lower flippers (both left and right) would only fire sporadically, even if holding in the flipper buttons; upper flipper only rarely fires along with the right. Also, the flipper relay box on the solenoid driver board (a brand new Alltek) would click away like mad after first trying to fire a flipper, even after letting go of the flipper buttons.

The game does not make any sound or do anything when solenoid test gets to 23, “the K1 relay (flipper enable).”

I thought perhaps the issue came down to a bad EOS install—I actually think I used the wrong part at first, though I have since replaced it with the proper ASW-A20-34 and ASW-A10-45 switches, and the problem remains.

I reached out to Alltek, but they don’t know what’s wrong and can’t seem to help me diagnose the problem.

What do I do next, Pinside?

Alltek suggested the same, but I don’t understand—the wiring looks fine between the MPU and J4 on the SDB. Could there be an issue somewhere on the MPU, and if so, how do I find it?

In case this helps solve the mystery, the flipper relay box a) doesn’t start clicking away right away, and b) will start clicking even if I don’t hit the flipper buttons.

An update: I put in an old Solenoid Driver Board, and the problem resolved. So it seems there's an issue on the Alltek board. I'm sending it back to them for repair, and I'll be sure to update this thread with whatever is discovered to be the problem!