I have recently upgraded my alienware P4 to a N68C-S UCC with AMD Phenom 2 quad core 3.2 ghz with 4 gb DDR3 RAM, nvidia quadroFX 580. After i installed the motherboard and turned it on i only managed to get the cpu running at 800mhz. I fiddled around with the BIOS and managed to get it running at 3.2ghz so all was fine!

I have been running the machine for a month now and it has started to turn itself off with out any warning! When i try to restart it either wont turn back on or it starts up and the HD light flickers intermittently !?! If i leave the machine unplugged for about 20 minutes and then try to turn back on it starts fine but eventually turns itself off!!!!

HELP!!!! Could this be the power supply etc etc