Ok so I just built this computer and everything was going good. Then It just stopped powering on. I press the power button and nothing happens. Sometimes it starts up but quickly shuts off before anything happens. I can get it to power up by taking the power botton jumper off and putting it back on agian, but it wont stay on. I am not sure what the problem could be.

Could be your power supply, motherboard grounding out, or an "iffy" connection with the ATX power connector (assumption that it's an ATX PSU).

Disconnect everything from the motherboard, plug it back in. If that does nothing, take the motheraboard out of the case and do it all over.

Check to make sure that your LED/AKA Accessory Connectors did not come loose 1st

All the LED are ok and when I unplug every thing and plug it back it does the same thing.(and it is an ATX PS)

What about the 12v jumper
What kind of fan is cooling your processor and where is it located.

I have one plug in I don`t think it has a place for another.

What another place for the 12v or the fan .....where is your fan located thats cooling the processor?
How may hours did your computer run for

another for 12v. the fan is right above the processor. it ran for less then an hour.

Above the yellow thing and left to the slots thats where you had it in right. So it only ran for 1 hr tell me you put thermal grease between the processor and the heat sink?I still think this is a grounding issue having to do with the screws

yes, and I bought it already with the cpu on, and I screwed it in properly. I even tried it without the screws.