I have an AMD Athlon XP 1.3 ghz processor on a Gigabyte 7IEXH mobo with 512 megs of RAM, a clone ATI 9250 Radeon video card, and a host of other stuff that probably doesn't matter yet.

The problem I'm having is UNLESS, I leave one side of the case open, with a fan blowing into the tower case, my system lapses into a constant reboot cycle.

I am fairly certain it's not the hard drive, as I have a drive bay that I can swap drives (after power off) and tried a different drive, with the same results.

Talked to a tech, and he confirmed what I thought, that if the CPU was over heating, the system would shut down. Problem is this, before I put the fan to blowing on the system, I've seen the temp meter in the BIOS screen top 74 degrees centigrade. The CPU fan is working. But I'm at a loss as to what is going on. Anyone else ever have this problem?