Help! Computer wont turn on....motherboard issues?

So I'm a little frustrated and dont really know where else to turn. I recently built a new rig (see sig for specs) and had been run a stable safe OC for abot 1.5 weeks. I was visiting my family and decided to take up the computer with me....upon setting it up, everything was fine, it booted up, posted, no issues. The following morning, I tried to turn the computer on, nothing. No power, no fans spinning, no monitor output, nothing. I did have two lights on the MOBO on, the power light and the reset light....I tried starting with those, no go....so I unplugged the computer from the power cable, pushed the on button for 30 seconds, plugged it back in, and voila....it started.....then later, I shut the computer down...attempted to turn it back on 1.5 hrs later, same problems, had to unplug the power cable and do the same th ing to get it to start. Sometimes when I turn it on after doing the above mentioned task, I get either no output to the monitor, and then have to push the reset button, and then I get output, but I get a screen that tells me I need to go back into the bios to load defaults.....I am so frustrated!!! I dont think its the PSU....but I could be wrong....my initial instinct was the motherboard but I really dont know......anyone have any suggestions?