Figuring out an issue with a client's Centaur. Says the game worked perfectly before being packed up and moved. Game will get to flash 7 and then crash with a slight burning smell upon boot. Narrowed it down to J2 on the MPU causing the issue which runs the switch lines. Narrowed further to three separate wires on the connector by repinning, any of which will each individually cause the issue. White green, white blue and brown yellow. Figured there was a switch line touching something carrying voltage but three seemed odd, as did the voltages measured. Measured voltages at each one:

DC Voltage:
White Blue: 4.95
White Green: 8.26
Brown Yellow: 8.31

AC Voltage:
White Blue: 2.7
White Green: 3.6
Brown Yellow: 3.52

Searched the bottom of the playfield and tried to find continuity with any of those switch lines to anything else but wasn't able to. Open to suggestions of what to test next.

Other data: Alltek MPU and SDB.
Photo attached is what the SDB looks like when the game crashes with J2 plugged in.

IMG_2515 (resized).JPG

Yes, so this is not the typical situation where you need all the balls in the trough to boot. I am aware of that quirk with Centaur. The game will flash the seventh time, begin to do the boot callout but then quickly cut off and all the momentary solenoid LEDs on the alltek SDB will go red. From my understanding this is an issue with voltage getting into the switch matrix where it shouldn't.

My questions are:
Why 3 individual wires are all reading voltage? Do they have anything in common that I am not seeing?
Why are the readings voltages that aren't present (to my knowledge) on the playfield?
How I can track down where these lines are picking up voltage where they shouldn't be?