24" LED Cinema display won't wake from long sleep

Just bought a brand new 24" iMac and matching 24" LED Cinema display. Clean 10.6 installation out of the box. Day one, everything working ok except if I let the system sleep for a while the iMac will wake up if a key is pressed or mouse moved, but the display will not. No problem if its been asleep for a few minutes or even half an hour but leave it say 6 hours (say I'm downloading something overnight) and I get this problem. It will work again if I reboot the iMac or disconnect the display's power though just disconecting the display from the iMac display port doesn't seem to fix it.

Has anyone got any ideas? Apple tech support had nothing except suggesting resetting the PRAM. At the time I wasn't aware the problem was only happening after an extended period of sleep so I thought it was fixed but its clearly still there. Help!

R

iMac 24", Mac OS X (10.6.1), 24" LED cinema Display

Posted on Sep 30, 2009 2:31 PM

54 replies

kabaker

Level 1

40 points

Jan 6, 2017 4:17 PM in response to reid007

Still a problem. All I got from Apple is the same old Voodoo. Shut down, restart, reset, unplug, replug, etc. Here's what does work: 1. Put iMac to sleep from the Apple menu. 2. Count to three slowly. 3. Click mouse. If that doesn't work, go to 1. Repeat as needed. Eventually it works. Don't plug or unplug anything. Don't shut down/reboot. Don't reset anything. Don't replug anything. Just do 1, 2, 3 and eventually it works. This is not satisfactory, and I'm planning to continue this conversation with Apple support as long as my warranty is in effect on my iMac.

Feb 18, 2010 9:48 AM in response to alpa

Me too, too. Any news on this?

nunec6

Level 1

0 points

Mar 3, 2010 2:25 PM in response to manic

This is another me too. only now its not waking up when restarting. I also have it converted but its not the same converter as the one posted above

xvx29a

Level 1

0 points

Mar 29, 2010 12:29 PM in response to xvx29a

This no longer works for me, and now I can't get the monitor to Apple Cinema Display to turn on at all after 10.6.3 update.

RichMBP

Level 1

8 points

Mar 31, 2010 11:35 AM in response to xvx29a

Same issue after 10.6.3, i can see the main external display but the MB Pro display can't be detected

Aug 30, 2010 5:52 PM in response to Dead Drive

Ok did not work. Off to the genius bar

Dec 28, 2010 3:19 PM in response to Guy Parrot

Y'all musta have your problem fixed cuz this everyone's been mucho silent in the past few days!

Jan 24, 2012 11:04 PM in response to reid007

Is it a glossy screen...that could be the problem.

Dec 14, 2014 2:16 PM in response to Celestrium

Hi - I am running Yosemite and I am having this exact problem. I cannot find the folder or the .plist file you recommend deleting. Any idea where this would be or what it would be called in Yosemite?

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24" LED Cinema display won't wake from long sleep