Well thats the thing...it doesn't shut off all the time. So I would have to remove a component and leave it our for a long time to see if that was the culprit. Sometimes it hums along just fine and other days it shuts off. A very strange problem. I'm going to investigate the internal case wiring to see if perhaps that is where the issue is. It can't be any of my components. If it is the PSU as I first suspected it has a 5 year warranty on it so I'm good for an RMA. It started doing this about 6 months ago about 6 months after I built the thing. The first time it did it was when I was programming some GPU shaders. I honestly thought my shader code killed the GPU or my other code triple faulted the CPU when it happened.