Tonight I tried to troubleshoot this some more but am not getting any further. I checked the wires from the switch all the way up to the top of the playfield, and could not find any breaks or damage.
I opened up the head box to look and see if I could find any damage in there to the wires, found nothing.
While the game was in play mode, I had the playfield up and used an alligator clip as a jumper to see if I could generate some type of response. I put the clip on both wires going to the switch, no response. A step back there is a piece of electronics that looks like a s'more or sandwich, it's block shaped with 2 tabs sticking out of the side. I put the clip on those 2 wires, nothing happened as far as the game detecting the connection goes.
The switch matrix test is still reading a "31" which repeats. If someone could help with some suggestions for this I'd really appreciate it, as I can't figure out anything else to try by myself.
In the interim, I was able to get another switch working again that was in the A-B-C-D lineup at the top. Somehow the switch was no longer making contact when it was supposed to.