G4 continually sleeps

Helloooo -

I recently installed a new 120mm fan in my G4 to quiet the noise FYI. I was toying with the energy saver settings to stop the comp from sleeping while I recorded in Pro Tools. It would sleep, I would wake it, put in my password cause it was protected, and then it would promptly go back to sleep before I could even do a thing. I am talking ONE SECOND and it was asleep again, asking for a password to wake, etc.

So I rebooted, and the same thing immediately started happening after I logged in. So I shut her down and have no idea what to do cause I can't troubleshoot if it keeps falling asleep.

Mac OSX 10.4 on a MDD G4

Pro Tools 7.1.3cs

Any guesses? Solutions? Obv don't want to have to reinstall... FWIW I do have 10.4 and 10.6 on the computer on diff partitions so I could possibly reinstall on one, but it is currently on 10.4 as the problem persists.

Thanks for reading!

Billy