iMac screen no longer going to sleep

[greg555]

I have the Energy Saver set to "Put the display(s) to sleep when the computer is inactive for" 10 minutes. It used to work fine but about a month ago it stopped turning off the screen.

I have 5 users set up on my Mac (and one administrator account that is normally not used) so I think it may have something to do with the screensaver setting on the other users (my kids and wife) but I don't know what has changed to make it stop working.

Is this a known problem? Any suggestions?

Thanks - Greg

(I'm running Leopard 10.5.8. Hardware is in my sig.)

 

[greg555]

Any ideas?

Thanks - Greg

 

[ivnj]

http://support.apple.com/kb/HT1776

 

[TheZA]

Yes, I had that problem, and after searching various forums I solved it by resetting the system management controller (SMC). I believe the process for resetting the SMC is different for different iMacs so check apple support. Mine is an early 2006 iMac. The SMC reset process for my iMac couldn't hurt anything, is very easy, and does not reset PRAM - so it was no big deal even if it didn't solve the problem (but it did). The process for resetting SMC on early 2006 iMac (and maybe others) is: (1) from the Apple menu, choose shut down, (2) unplug all cables from the computer, including power cord and any display cables, (3) Wait at least 15 seconds, (4) plug the power cord back in, making sure the power button is not being pressed at the time, then reconnect the keyboard and mouse, (5) press the power button to start the computer.

Best of luck.