Cleveland, OH
Quoted from offdutyninja1:bobukcat the reality is confusing as well. Let me try again.
1. Switch matrix was connected to J207 and j209.
2. Row 8 was fully out, and column two was partially out.
3. Performed the diode test between J207 and J209. All switches closed except for Row 8 (pin 9 on J209).
4. Performed the diode test between J207 and J208. Everything worked fine.
5. Plugged back into J207 and J208 - all problems solved.
So obviously the row problem was on the MPU.
And most likely something is loose between switch 24 and 25, and moving the play field led to that error (and subsequently fixed it).
So I guess my remaining question is about the likely cause of the pin 9 failing.
Was it most likely the previous battery damage?
Or could swapping switches have caused it?
Yes, seems likely that corrosion killed the section on the MPU that would effect areas related to your issues. Could be that the corrosion was never fully neutralized and is still eating the board. This is a tough situation when you don't have a spare board handy.
Seems like you have some resistance between J209 pin 9 and the diode(D10)
