I do not have a schematic in front of me but I believe these switches work on 12VDC.
This comes from the logic power supply,through the mother board, through the BMDC.
If that wire was a 12V supply wire and it shorted, it may have blown L2 on the BMDC.
There are not a whole lot of these machines out there. Thus my memory is a bit fuzzy what is inside. So see if I am correct.