iMac Display not sleeping

[mat25]

I have noticed lately that my iMac screen does not shut off even though in the energy saver screen I have set the display to sleep after 15 minutes. Any suggestions of how to fix this issue? I have a Early '09, 20 inch iMac (OS X 10.6.6)

 

[aussiedj]

Could be a number of things.

Try putting the display to sleep - CONTROL+SHIFT+EJECT & seeing if it wakes itself back up.

If it does it could be:
Wake-on-lan
Mouse activity
There are probably a few more.

 

[aussiedj]

Otherwise, if you are a bit more advanced have a look at manually manipulating the settings via Terminal using this as a guide.

http://developer.apple.com/library/mac/#documentation/Darwin/Reference/ManPages/man1/pmset.1.html

pmset -g
Will give you an overview of the current power management settings.