Mac Pro 2006 won't go to screensaver/sleep

[xhale]

I keep having this problem and I can't figure it out. My settings are as follows: screensaver after 3 minutes, display off after 15, computer sleep after 30. I've adjusted all of these settings to no avail.

It had been SS/sleeping fine for the past few days and all the sudden it won't anymore. I've systematically eliminated all the applications running to see if it was one preventing the sleep but I can't identify any app causing the issue.

This is all that is running:

If I force my Mac into sleep using Dropzone or the 'Test' button in system preferences it will just stay in screensaver forever. It won't turn the display off or go to sleep.

I was thinking it thinks something is connected to it for file-sharing purposes, and is refusing to sleep because it doesn't want to break the connection. Even if that were the case and the computer wouldn't sleep the display should SS and then turn off.

Thanks in advance for any help...

 

[strausd]

Have you reset the PRAM? Not completely sure if that would fix it but its worth a shot.

 

[xhale]

PRAM has been reset a few times in the last month or so while trying to resolve the problem. I don't remember it doing anything.. start up got a little faster though

 

[Bielski]

I've recently started having the same problem. When I logout and log back in the problem goes away. After a few hours of use the screensaver and sleep won't go on anymore. I've zapped the PRAM and reset the SMC. A call to apple care had me me delete caches and a number of preference (.plist) files. The problem came back the next day. My wife's user on the same machine doesn't have the problem. Did you ever solve the problem?
I'm on a dual-core 3.06ghx intel imac mac (mid 2009).

 

[ProfDrLuigi]

Try to unplug all Non-Apple USB-Stuff.

 

[tomscott1988]

I had this problem

I had this problem. There are a number of reasons that your pro wont go to sleep. At the time i had an old powermac G4 attached via ethernet with internet sharing turned on, even when the powermac wasnt on, the pro wouldnt sleep because it was constantly sending data. Another reason - have you checked your sharing options? file sharing can stop the pro from sleeping if other computer automatically connect. So try turning off all your sharing settings to start with, See what happens.
Another problem - have you added any non apple hardware like a dvd drive? i added an old dvd ram drive manufactured by LG great drive, worked great, osx was compatible and burned all media types supported, but the drive continued to search itself even if there was no media in it every 15 mins or so, meaning the computer would never sleep.
I didnt have the same problem with the screen saver so just had the monitor turn off instead. But i used to leave the pro on for days while it was doing tasks and it never slept, i just dealt with it until one of my drives died after only 8 months but the computer was always on and never slept.. so took out the DVD drive and it works perfectly now. Fortunately i back up everything weekly so data loss wasnt a problem just annoying i had to be with a TB drive.
Like discussed here remove all usb/firewire devices, some old external drives stop computers from sleeping. Other than that the Pro has always had sleep issues check google 'mac pro sleep issues' and the web is full of people having problems apple even has a document on their site describing what you can do to help with resetting pram etc. Other than that i cant think of anything else.

Hope this helps!