iMac not sleeping well

[Emuleem22]

Hi.
Most of the time, my iMac Intel 20" has no problem sleeping, but once in a while (but consistently), it doesn't sleep. The screen goes all black (but you can still see what's on the screen,,, kinda like when you turn the brightness all the way down on your ibook/powerbook)

This happens even when I try to sleep when no app is running, as well as when I try to sleep it when bunch of apps are open.

What do you think is happening? I never have sleep problem with my powerbook g4.

thanks

 

[thadoggfather]

I think your iMac needs Nyquil; it's an insomniac.

(i couldn't resist with the thread title)

 

[BlindingLights]

Try taking it to the genius bar. Your mac could either be defective or it's something small they can fix.