Reposting with updates:
I wasnt trying to start beef or pit people against one another!
So all the test points on the board, and the voltages sent to the MPU and Driver Board and Sound Board are all present and correct.... but I'm noticing now that the Sound Board Power Supply fuses are blowing kind of easily. As far as the Power Supply Board in the backbox, I think just the LED shorted? R12 right above it is extremely hot and thinking that maybe that caused the LED to fail?
I went through and tested S1-S32 on the sound board for both the speech and the sounds. For the speech, initially, they all worked 1 2 4 8 16 32. Cute voice. The sound however only works for grounding 1, 2, 4, and 8. Those 4 come from Z13 on the drive board, that I know, but I'm having trouble tracing down where the 16 and 32 points are coming from. This whole issue started with the sound as I was putting the playfield back in its place, so, I'm inclined to think that s16 and s32 are the "non-switch triggered" sounds that play throughout the whole game and come from connectors or bundle under the playfield. But I'm just a little lost to be honest.
One of the things I love about this forum is that I get to talk these things out, and in writing them out, I understand the whole process more and I'm grateful for everybody who has helped me figure these things out.