I'm pretty sure this is the issue but I thought I'd go ahead and double check anyway. I have any old DFI (yeah, not my favorite company either) 939 socket DDR 400 Crossfire capable motherboard. Recently, the computer would get to a point where after only a few minutes of being turned on, it would reboot. After the first reboot it would go through a continuous boot cycle that barely made it past post. At first I thought this was attributed to an overheating processor (X2 4800+), but soon there were more things to come.
It then reached a point where I could no longer get an image on my CRT, a known good monitor. At first I thought this was an issue with my x1900XTX, so I swapped it out with another but continued to have the same issues. I then noticed that while the LED on the DVD-ROM drive would light up, I could not get the tray to eject.
I then noticed that once I could no longer get an image on the monitor, the machine stopped rebooting sporatically, cancelling out the overheating processor theory.
All the fans spin so the system is obviously getting plently of power. Is this an issue with the board? Again, I'm pretty sure it is, but I thought I'd hit up some input just in case.