PC doesn't start at all

Hello,

I was doing a disk check prior to starting windows and it was taking an hour so I decided to just shut it off manualy (not the smartest thing I know). And I believe I fried my power supply, so I replaced it. But still doesn't help nothing beeps, fans dont spin, the pc doesnt make any sound. Theres a light on power supply and mother board I tryed unpluging everything : hard drive, cd rom, ram, NIC and start wiht out nothing changes. One think is left is bad motherboard. Could there be anything else that would do that, I would apreciate the help.