Okay, so I'm still stumped but on a totally different problem. Firstly, I'm using the Donkey Kong power supply conversion kit from ArcadeShop.com to get my Donkey Kong PCB working in my Popeye cabinet. As of now, all I've done is disconnect the old power supply and connect the new power supply according to the instructions
here. For those not familiar with the conversion power supply, it has a red light on it that verifies a good connection. When the harness is not connected (Meaning the 9P and 10P are disconnected) the light comes on, but once the harness is connected (Regardless of whether or not the PCB is connected) the light doesn't come on. This led me to believe there was a short circuit in the PCB, but after replacing the board with one I can verify works, the problem persists. So obviously something is stopping the connection from completing but I can't figure out what.
I might add that using the old Popeye power supply to try to run Donkey Kong produces a blue screen (As opposed to a white screen with the new power supply) which after looking at
this thread I believe is a result of the lower voltage.
I understand that the Popeye harness is lacking the +12 and -5 V pins on the wiring harness so I've tried running wires from the new power supply to the 5, 6, E, and F ports on the edge connector but I don't know if this has anything to do with my current issue.