well if you tried all that my guess is the ram is fried. that tends to be the 9 times out of ten answer for this sort of prob. have you tried removing one of the memory and then swapped them over? i have actually known both ram modules to fail at the same time. if its not ram then you've most likely fried the mobo
its not the cpu fan, or the ram, im guessing the god damn front panel prongs!! and i said im going to bring it in to a "professional" so stop telling me what it might be, because i already know what it most likely is.