Xserve shuts itself off and boots at will

Okay, there's a lot of smart Mac guys here, so lets see if any of you can figure out this stumper.

Our Xserve G4 (RackMac1,1) went incommunicado a few years ago was left in this state until I pulled it out yesterday. I started my mission with a triple PRAM zap, and like clockwork it decided to boot perfectly into Mac OS X Tiger Server.

I decided to upgrade it to Leopard, this machine only has a CD drive, so I hooked it up to my MBP via FireWire and attempted to burn the install DVD to one of the hard drives (since all it's data is irrelevant / four years old anyhow). It starts copying just as always on the various computers I've done this to, it says "20 minutes remaining", so I leave the server room to go do other things. I come back 20 minutes later to a MBP saying "18 minutes remaining", and a shut down Xserve.

Rinse and repeat this process. Perhaps something weird happened.

I decide perhaps it doesn't like being in FireWire target disk mode and boot it back up to Tiger to download the disk image and burn it to the hard drive. After about 10 minutes of uptime, it just shuts down. Not even a soft shutdown. Total loss of power. I had some other stuff to do in the server room and after about 15 minutes I look back and there it is, fully booted, sitting at the login screen.

I ask you, what sentient force has made a victim of my Xserve?! :(

Solution 1:

The original G4 Xserve was prone to structural 'sagging' after spending a while in a rack. I'm not aware of any specific fix for this problem, which causes random kernel panics / shut-downs / other weirdness; later model XServes were not affected (not sure when exactly, but I've never seen this on any intel xserves, while I did see it on a significant number of g4 serves).

http://tidbits.com/article/11735

Sorry for the bummer news :/ If you can get your hands on a late-model intel xserve, they still hold up pretty well. I use several of them on a regular basis.