Cheapo Psu Dead?

well i bought a cheapo psu about 11.00 dollars shipped of ebay new. its a 500 watts or something, anyway before i had my comp built i used the two wires and started it because i was bored. fan started and the hard drive that was plugged in started. but when my comp was finished i plugged it into the motherboard and i try to start it and nothing happens. so i do the wire trick again and it starts. Wuts up with that? and please dont limit your anwsers to obviously a cheapo powersupply

It would help if you posted some more info for us to go by.

My first guess would just be inability to power the components you have.