As many of the regulars here know, I just acquired a new-to-me G5 Quad. Today, my power cord I've been waiting for came in. I burned a copy of ASD 2.6.3, which I then booted on my Powerbook to make sure it worked, which it did. I popped it in the G5 and tada, it started to boot. However, when it got to the blue "Apple Service Diagnostic Loading" screen, it froze. This happens consistently. Digging deeper, I noticed that a red light is on near the front of the case, labeled "Overtemp". The problem is, the machine has barely started to boot. When that light comes on, the CPU heatsinks are still cool to the touch. Sometimes after awhile the machine shuts off, I assume due to the supposed overheating. However, even when this has happened, the CPU heatsinks were barely warm, not uncomfortable to touch. It does seem like the LCS pumps are running. I have what I assume is a "two-pump" Delphi system, since it has two separate black housings which I assume are pumps on top of the CPU heatsinks. There is also a sticker labeled "Cooligy" at the base of the LCS enclosure. While the fans sounding like a jet drown out any noise the pumps might make, I do feel a slight vibration laying my hand on them while the machine is on. I started it once with their power cable unplugged and could not feel the same vibration, so I feel confident they are at least trying to work. So, I know from my highly unscientific "touch"-test that the CPUs (or at least the heatsinks) aren't getting too hot, but I can't get the machine to boot to the ASD DVD to calibrate the cooling system so it knows that. I'm hoping some of the super knowledgable folks around here have fought this battle and can share some wisdom with this G5 newbie. Thanks as always for being awesome!