It sure sounds lemon like. The only other thing I would try at this point before buying a replacement board on E-bay is to "breadboard" the unit by taking the mobo out of the case ( the case might be shorting out the mobo somewhere ) and setting it up on a non-condutive suface like a book and try it there with all new power supply, ram, video, etc. Also, look for scortch marks on the backside of the board in case it was a surge that done it in. Good luck!