My G5 Doesn't Want to Sleep!

Question

Can't get my G5 2.7 Dual Processor G5 to sleep. When I select "Sleep" it spins down to sleep, monitor goes off, then immediately clicks, fan revs and it's back up again. I've unchecked all my Energy Saver options, but still can't get the bad boy to take a nap. I see others have sleep issues, but don't see this specific problem here. I don't use sleep often, but it's frustratinig when I do.
G5 2.7 Dual Processor   Mac OS X (10.4.3)   2 GB RAM

Answer 1

This is for a Mac that won't sleep.
First, read things in Apple doc.#25801 on sleep settings.
USB devices and hubs often cause Macs to not sleep or wake quickly from sleep (notably HP printers and scanners, HP all in ones, and Cannon scanners). Disconnect all USB except for keyboard and mouse and try. If it sleeps, add one back at a time testing after each one to find the culprit.
If you've set your Mac to recieve faxes, it may not be able to sleep. It might also have a damaged preferences file.
If you use your Mac for faxing, open System Preferences. click Print & Fax, click the Faxing tab, and uncheck the Recieve Faxes On This Computer box.
If that does'nt work or you've never faxed on your Mac, go to Finder/Hard Drive /Library/Preferences/SystemConfiguration and delete the com.apple.PowerManagement.plist and com..apple.AutoWake.plist files (if your Mac asks, type your admin. password).
If the latter file isn't present in the folder, go to user name(probably your name)/Library/Preferences, delete the com.apple.systemuiserver.plist file, and reboot your Mac.
Hope this helps!
P.S. One member here reported this (Michael Gleason);
"I have had this problem with my IMac G5. It is surprisingly irritating. LaCie's Silverkeeper backup software was the cause. By default it gave itself permission to wake up the computer to check if a backup was needed. Do you have this or a similar program installed which has scheduled activities including wake-up permissions as an option?"
Dave Hamilton provided this link, xlr8yourmac.com, to a member, which addresses failure of deep sleep with some users that updated and added new FireWire and USB cards.
tomhorvat adds this; After few days of messing around I found out that I had desktop background (wallpaper) set to change every 1 minute.
After unchecking "Change picture..." in system preferences (under Desktop/Screen saver), my powerbook went to sleep all by itself.
Cheers!
DALE