PowerMac G5 Will Not Sleep

I can confirm the CD in the Drive™ trick works for me too.
Powermac G5 will definitely sleep automatically if there is a disc in the drive.

I was about to replace the superdrive - thinking that it was faulty and somehow preventing the mac from sleeping - but after reading many (many) apple discussions about this same problem, it must be a 10.5.x issue.

Can anyone else check the CD in the Drive™ trick works for them?

Another test to confirm this PowerMac G5 tower sleep problem is connected to the Superdrive:

1. Turned off mac.
2. removed Superdrive from my G5 tower.
3. Restarted the mac with the optical drive bay empty.
4. Mac sleeps automatically as per Energy Saver preference pane.

5. Turned off mac.
6. Returned and reconnected Superdrive.
7. Restarted.
8. Mac does NOT sleep automatically.

So there you have it.
The automatic sleep issue (well, for me at least) is definitely caused by my Superdrive.

I'll be getting the optical drive replaced soon and will post my findings when I do....

This is a problem/bug which came to my attention after updating to 10.5.7.

Reverting back to 10.5.6 and prior remedies the issue.

CB100--You didn't mention unplugging USB devices in your first post. In my experience a failure to go to sleep has always been traceable back to a USB device or a USB card. Maybe this is what fixed it in your case?

Other posters had mentioned that they'd already unplugged all USB devices, so evidently there's something else going on, in at least some cases, but I'd always recommend checking for USB issues first if there are problems with sleep.

I have replaced the Apple shipped standard superdrive with a LG HL-DT-ST DVD-RAM GH22NP20.

The sleep problem is resolved. Everything works as it should now.

So there you go, it WAS the optical drive all along.

On a whim, I finally decided to investigate further.
(There was nothng on TV...)

I removed my existing HDDs, installed a 'new' HD, Clean install of 10.4.6and then the 10.4.11 combo update, and my G5 would sleep just fine.

So I did a clean install of 10.5.0 and the G5 would still sleep.
Applied the 10.5.8 combo update, and BOOM! My G5 won't sleep.

I tried a different LG DVD-RW (with -DL support) and still no sleep.

Swaped it out for a PIONEER DVD-RW DVR-108 and my G5 sleeps again.
(So far... Touch Wood!)

So it seems that it is the OS interacting with the optical drive that causes the lack of sleep.

Now if I could solve the Kernel Panics I get if Processor Performance in Energy Saver in System Preferennces is set to Automatic.
In Highest or Reduced, no Kernel Panics....

The same thing happens to me: display sleeps but machine doesn't. However, I have 10.4.11 installed, not Leopard. You think it could also be my Optical Drive? Sometimes it clicks at repeated intervals after the scheduled sleep time (longer intervals than the usual rapid fire clicks when it gets put to sleep manually).

Must admit, it hasn't bothered me so I haven't checked the system logs yet to see what prevents sleep.

It sure sounds like that could be it.

Any specific disk? I tried it with the first that was lying around, the Panther install disk 2, and it didn't work. Maybe it's to do with the disk: when I logged out SecurityAgent crashed and instead of the login window I got the Darwin console login prompt!

Well, the earliest 1.6GHz G5 did come with X 10.2.7 (G5), but the Dual 2.7GHz needs at least X 10.4 (8A428) to boot drom, but just reading them shouldn't matter.

Well, I replaced the Apple super drive with a Samsung light Scribe drive and the machine still will not sleep. I even disconnected the drive cabling and that did not make a difference. I have also tried to disconnect all of my USB devices except my keyboard and mouse and my machine will still not sleep. I am running out of guesses and/or options here.

Does anybody else have a suggestion?

Does it make any difference if you try Manually sleeping it or Scheduling it?

My machine will manually sleep. It will not sleep through the automatic settings.

First, Safe Boot , (holding Shift key down at bootup), use Disk Utility from there to Repair Permissions, move these files to the Desktop.

/Library/Preferences/SystemConfiguration/com.apple.PowerManagement.plist

/Library/Preferences/SystemConfiguration/com.apple.AutoWake.plist

(Then Trash the originals, as "moving" it only copies them.)

Then reboot once more.

PS. Safe boot may stay on the gray radian for a long time, let it go, it's trying to repair the Hard Drive.

Schedule sleep & see if it works now.