amd 64 machine just went off and wont come back on

[mosehn]

2 days ago , all of a sudden my pc just went off and wont come back on
well the power comes on and the cpu fan spins , i dont see the gfx card spinning.
i put a diferent gfx card in and it still wont post to screen
spec is

geforce 6800 gt
amd 64 3500,
1 gig ddr
80 gig maxitor

could it be a dead motherbaord and gfx , the gfx card that was in at the time also wont work in this computer i am on now
dont know what todo

 

[Insanity]

Might have toasted one or more rails on the PSU (but its strange your cpu fan is spinning), or the motherboard is cactus.

Those are my bets anyway.

 

[Zefan]

What PSU have you got?