I have an MSI K8N Neo2 Platinum (939) with a 3500+. My power supply is an Enermax Noisetaker 470W. Also I use an APC UPS 770W. I purchased all of these slightly over a year ago. When I first got the system I had some problems of it randomly shutting down. But it never did that when I was around so I never saw it. I replaced the power supply and although that didn't solve the problem, it slowly went away. I've recently noticed it happening again, but I have been around to see it. The power in the rest of my apartment will be fine, I will hear my speakers buzz for a minute then the whole system just powers off suddenly. I have a friend who worked for APC and he ran me through all the tests for my battery backup and it works properly. So now the only thing I can figure is it must be my motherboard. There doesn't seem to be any actions in particular that seem to lead to this happening. Actually typically it happens when I am not even using my computer, or maybe just watching a video, and it happens randomly at no set intervals. It doesn't seem to be doing any immediate damage to my system although I am concerned about long term effects. Any assistance on how I might troubleshoot this or correct this would be greatly appreciated because I have no idea. Thank you.