Power doesnt turn on.. Motherboard problem? or PowerSupply problem?

[tensy]

Hi guys.
I dropped my desktop (not that hard) when it wasnt turned on,
and i saw a little spark from the inside of the desktop.
I tried to turn on my desktop, but the green power LED goes off, and
nothing happens. The fan doesnt start... nothing.
i tried disconnecting things one by one. RAMs, Harddrive,Graphic card, even the CD drive.
no changes were made. it was still the same.
However, when i disconnect the motherboard, the LED never went off but still fan doesnt start and nothing happens.
Whats the problem?​

 

[foothead]

Unplug the 24 pin atx plug from the motherboard and jump the green wire to any black one with a paperclip. If the power supply turns on, the motherboard is most likely the problem. If it doesn't, then it's the power supply.