Mac Pro won't sleep naturally

[jwt]

This problem started after installing a second HD, starting Time Machine back-ups, an additional 2 GB of memory, and an EyeTV Hybrid. That's a lot of variables, so I'm wondering if anyone has had this issues after any of these were installed/enabled. Help.

Mac Pro 2.8 Quad
Ati 2600
4 GB
320 GB/500 GB

 

[fsron]

Mine did the same after adding some things, I don't know which item caused it. Shut the computer down and unplugged everthing for it to reset. Works perfect now. I have had the computer for about two weeks now and no issues.

 

[geon]

When mine does this, it almost predictably will have a "won't wake from sleep" issue. As a matter of fact, It just happened and had to press the power button to shut it down. I tried to get it sleep on its own but to no avail. I zapped the pram, did the power management reset (forgot name), etc. Oh well. I've also done all the updates, firmware too.

 

[surflordca]

It's a work horse. It's just not tired

 

[benpatient]

have you tried putting it on its belly? usually works for me.

 

[krye]

Some apps that have background services will keep your machine awake. If they keep accessing the hdd, the machine won't go to sleep.

Here's a good read from Apple's support pages that talks about some of the reasons why your Mac might not sleep.

http://docs.info.apple.com/article.html?artnum=303698

 

[WardC]

Sometimes this happens when you have a USB peripheral that's sending a signal. If I have my machine on sleep and I turn off one of my USB MIDI controllers (MIDI keyboard or evolution UC-33), then the system will wake from sleep. Make sure all your USB stuff is turned off once you sleep your system. Hope this helps.

-Ward

 

[jwt]

I found the problem. It must be a bug in Leopard, but having the "Sleep HD when possible" option checked caused the problem. Interestingly, this would also cause my machine to wake between noon and 5 pm. After unchecking, it behaves normally.