Having issues with Junk Yard, randomly (and rarely) exiting the active game. Sometimes it says "I hate dogs" and goes into a tournament selection mode, other times it will just end the game. Not power resets, but premature termination or interruption of game play. Flaky RAM? Thoughts? Thanks!

Will do, thanks.

No switches stuck on.

New info, game now slam tilts during multiball. Checked switches in column and row of slam tilt switch and all appear to be working properly and afen't triggering other switches. Any more thoughts?

Replaced all switch diodes in row and column, inspected also. Issue remains.

Was able to simulate the slam tilt in switch test, which is a big step forward!

If 11, 18, and 28 are closed, 21 closes (slam tilt).

Simulated on board using jumpers and diodes and issue is also present.

Where on the board to start?

Yes, unplugged playfield connectors from CPU board and used diodes to turn on 11, 18, and 28. 21 also came on. So I'm confident it's a board issue.

Ok, will check column strobe with the scope. I noticed the 2803 (U20) is socketed, I'm assuming that's not how WPC-95 CPU boards shipped?

Thanks everyone, will post when I discover more!

Chris wins.

Columns checked out with scope.

Did some more playfield switch testing and started getting a row 8 GND short. Traced it to the shooter lane switch touching the autolauncher touching the shooter rod (which is grounded). Switch looked a bit rough so replaced it (switch 18) and now everything works 100%.

I am still confused why I was able to reproduce the previous slam tilt error by jumpering the switch pins on the CPU, maybe I had a diode backwards...

Thanks everyone.