I undertook the task of removing the CPU in order to possibly upgrade the software. I was very careful in labeling all of the wires and their connection points - with the exception of one. It's the plug at the bottom of the CPU box. When I pulled the plug, I was quick to label it. Unfortunately, when I was able to reveal where it went - there were three possibilities. Eeeek! See below. Any idea which one of these three identical plugs gets the wire?