One of the last little problems I had to solve was the front panel wiring, the panel seen below features a common ground for everything: LEDs, and switches.
I tried to reuse the switch as is but there was no way to as the old PowerMac was wired very differently than ATX machines. So I soldered the wires directly onto the board and used my Dremel to cut the contacts as the common ground was causing a short when plugged into an ATX board (I tested on a POS system first).
OEM Apple front panel board:
10 mystery wires with a common ground in there somewhere:
Problems solved and new LED installed:
My camera ran out of battery power shortly after this point so there is a lot of custom cable construction missing from the log, including a custom extra long front panel USB cable. I kept working while the camera was charging and got this beast wrapped up just in time before the kids got home.