Ask Max: I cannot get my G5 computer to remain asleep - help!
I have a G5 running 10.4.11, 1.8, 1gb very recently I cannot get the computer to remain asleep. I have reset pram & smu-pmu. When booted in safe mode will remain asleep. Any ideas?
Just like with people, a Mac insomniac can have many potential causes of sleepless nights. The first place to look is with expansion cards. More often than not, the problem lies with a PCI, PCI-X, or PCIe card that is doing some low level communication with the rest of your Mac. That communication could be causing it to wake from low power mode. If you have any cards installed it would be a good idea to remove them and see if the sleep behavior of your Mac computer returns to normal.
It can also be due to a software-based problem. A good test would consist of creating a new user account on your system and log into it. Without starting any applications, put the computer to sleep and see if it stays that way. If it does stay sleeping, then there is something running in your main user account that wakes your system, and you should look at your user account's login items for suspect applications.
If your Mac still fails to sleep in a clean user account, you should see if you have a setting in the Energy Saver System Preferences that would cause the system to wake. Under the Options tab uncheck anything under the "Wake Options" section. Also click on the Schedule button and make sure that there aren't checked items in that section.
I hope that gets you going it the right direction