Ok, so right before Christmas I built a brand spanking new computer for myself. Here are the specs: AMD Phenom II x4 965 4gigs of DDR3 2000 ATI Powercolor 5850 ASUS M4A79T Deluxe HEC Zephyr 750WATT So here is the problem... right after I built the machine I started having problems. Very randomly it just shuts off on me. When it shuts off it is almost like the power supply is dying on me but the lights on the motherboard will stay on like it is still infact getting power. I am unable to get the machine to power back on until I completely unplug it from the wall and cycle the power to it totally. My first thought was that it could have been a bad GFX card, but since I still have my other computer with me I popped my nVidia 9600GT into it... and BAM! After about a minute or two, it shuts off on me again. I then shifted to the motherboard and thought it could be that. I went so far as to RMA it already and got my replacement in yesteryday for it. I installed it and hooked everything back up and was in the BIOS setting everything back up (the clock, etc) and *poof* it shuts off on me while I am just sitting in the BIOS. So now my focus has switched to it possibly being the power supply or the CPU. I am unsure which it could be at this point but I will say when I first started having the problems I ran a CPU stress test and it ran that fine for around 2 hours. Basically I am just looking for some thoughts or ideas of what could be causing the problem, so anything would be great! Thanks in advance!