My computer died

I was changing some floppy drives trying to figure out if any of them work... All the sudden i turn on my pc and the damn thing wont even wake up... I mean it doesnt get to the Bios screen and shit...

The monitor just goes "Power off" standby mode or sth

So i think its the motherboard but not sure... i will try and changing the PSU, HD, RAM and even GFX...

GG : )