Hi there!
I bought a Project counter force, and have run into a strange set of behaviors:
things i have done:
new rottendog power supply grounded to speaker
docent harness from power supply to CPU
Repinned Connectors from CPU to DRIVER BOARD
All fuses checked, all coil resistances measured OK
Had bad Q relay coil, replaced with new coil.
new Niwumpf System 80 Board

the problem:
The unit powers on just fine and goes into attract mode
can cycle all coils ( Coin door stuff disconnected tho) and all lights and switches thru niwumpf. Each switch test fine, etc no noticable problems.
Start a game and the soundboard plays the first couple sounds.

The first time the ball touches a switch ( yes, ANY switch!!) the LED on the Niwumpf board flashes 3 times, locks up and displays a couple very bright random characters on the displays.

confused, as the switches test fine. if it was a short/accidental contact on the switch matrix , it would be only when one switch trips.

Im stumped with a hypothesis that fits the facts. sound board? ( why would sounds work in test but freak out CPU during game?) harness connector? (theres no common wire between all). Some kind of loss of 5V power? ( the main capacitor has been replaced on the bottom board but i think thats 12vdc anyway?)

Im stumped... any ideas?

That’s so wierd!

I guess some of the lights flash quickly , almost too quickly... but they only flicker once. The test menus and everything else work perfectly!
I almost wonder if the drop bank coil logic is reversed or something along those lines.. the cpu is expecting switches to be open when it activates the drop target coils instead of closed...so odd. I guess we will see what happens in the next couple weeks