I know people have asked about this in the forums, but I've not found any replies that lead to a solution... so I guess this is a bump for several threads simultaneously... please help me! It's driving me nuts! I've had this problem for well over a year now with my QuickSilver G4 (733 - 2001 model), leading me to believe it's not a problem incurred from recent OS updates... for the record, I'm running 10.4.2 All the following didn't help me obtain sleep for more than a few seconds... I've disconnected everything. I tried pressing that little black button on the mobo for 15 seconds, or so. I zapped the PRAM, and did that thing in the open firmware to reset the PMU. I tried removing all additional RAM, and putting back the original 40 gig hd. I tried wiping everything, and just installing a fresh copy of the OS. I tried repairing permissions more times that I can count. I tried removing the two USB cards that I added in, and running without them. No sleep. I tried putting on a 7 port hub for all my periphs, and disconnecting it when I wanted it to sleep. Tried replacing the battery inside the case, and still no luck. I've tried just about everything I can think of... and still NO SLEEP for my Quicksilver 733 (2001) My computer has the preferences unchecked for waking from sleep automatically. Still no luck.Nothing screwy going on in the Activity Viewer, either. From what I can tell, that is... By not sleeping, I mean I can select "sleep" from the Apple menu, and everything will power down, but them within seconds, it comes back to life. I HAVE maintained sleep for several hours when running my computer from a Firewire external HD with OS 10.3.9 on it. But why would that work when nothing else has? Please help. I hate haiving to turn my computer off at the end of the day so that it won't wake up in the middle of the night, and subsequently wake me up. My setup is the G4 QuickSilver 733 (2001 model) 768 Ram 2- 120 GB drives Pioneer DVD Burner Internal 250 mg zip drive 4 port USB 2.0 card no other additions inside the case outside the case: apple keyboard microsoft 5 button mouse griffin powermate soundsticks m-audio usb quattro (usually off) prolific external case (usb + firewire) with a 200gb drive - using usb (usually off) canon scanner please help!