just to make sure i understand completely.
refastened some wires while pc was on.. pc shorted, turned off.
appeared to be d945 motherboard bad, ordered replacement d945 motherboard, the m2 will not power up with either the current, or new d945 motherboards.
connected m2 to another known good motherboard, works fine..
according to what i understood, i would say that you have 2 bad d945 boards...
otherwise, it might be a bad m2-- have you measured any voltages off of it when it is supposed to be running?