I left things running all night and this morning it was still churning out random numbers so the MCLR/resitor issue was clearly the problem. If it crashed then the WDT (which I had set to ON) handled everything the way it was supposed to and rebooted it. If I can remember I can read the eeprom tonight and see what number is there and that should tell me how many times it re-booted.

Clearly the MCLR pin can have issues. I'm sure the wire that was on it, but not getting any voltage was enough to throw it out of whack. I can see now why debugging an issue like that can make one lose hair!

I used a 9 volt battery for my overnight test, but generally use a wall transformer and that's when I notice the heat. It is a cheap one so more than likely it is missing the capacitor.

My final board will be running off 12 volts and I am making that little AC to DC board myself so it should have a nice clean output (I had one of my old teachers from high school give me a schematic and tips on how to properly build that board to give a clean output) and I plan on adding a heatsink to the regulator just in case and because there is plenty of room for one.

I'm also going to be 100% sure to get the proper values for the capacitors for the regulator itself from its datasheet. I just don't have them available without ordering (so I am using the closest I do have for now).

I'll see what happens tonight with the "real" test with the multiplexer in the works.

Bart