This sounds like the Car2PC's fault. Maybe there was a little strand of wire from when you cut a power line that fell on the PCB causing a short and causing a fire. Hard to tell.
Do you have pics?
Also "overloading" a rail means you pulling too much juice, not the M2 putting out too much juice. That isnt how electronics work. Or else everything plugged into your house right now would blow up when you turn off a light since there is "extra" juice that is not in use.
But again, doesnt sound like an M2 problem at all.