I have a Pentium 4 1.7ghz with a Supermicro P4STA and 700mb of RAM with 2 133gb ATA133, It seems to just shutdown on its own all of a sudden, no message just goes to a black screen and the hard drive light remains lit and you can not power off or use the reset button to get it back on. It has to be unplugged. What do you think the issue with this is? The memory? CPU? Hard Drives? Power Supply?