I finished building a new pc about 2 weeks ago and it has ran fine ever since first boot. However, yesterday I put the pc into hibernation, got back a couple of hours later, pressed the power button and it just keeps restarting over and over on its own without even getting to the bios. I have disconnected everything and then tried using just the basics and the problem still persists. I have also cleared cmos and still no luck. Im thinking it may be the psu but i am not sure. Any ideas?
Do you have another PSU you can use for testing?
Check the "Reset" and "Power" buttons to make sure they aren't stuck down. If necessary, disconnect the front panel buttons and just short the pins for the power button with a screwdriver for testing purposes.
Yeah, if it isn't a stuck switch, then it is probably the mobo. A bad PSU will typically just shut down.
When you disconnected everything, did you take the mobo out of the case? If not, check under it for a dropped screw, paperclip, or other foreign object. Since it worked for two weeks, I'll assume you used the standoffs, but if you didn't, that could be a cause as well.