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

Since replacing the internal power supply in my 24" ACD (see 4 posts earlier) haven't had the wake from sleep issue again in the Mac OSX (Lion) environment. I do however still have the issue under Windows 7 (Bootcamp), where the screen won't wake from sleep. I think this is consistent with the reasoning of Lupunus and David above, and in my case is related to the different power management between Mac OSX and Windows 7.

I think my problem was initially a faulty power supply which was exacerbating the issue, but there still does appear to be an underlying problem with the ACD and power signals/management.

Thanks, Dawsman. Every piece of information helps. We initially had the MDP switch that switched between the AppleTV (converted to MDP) and iMac in Boot Camp. Initially the iMac would work much more reliably than the AppleTV, but it deteriorated at some point and now nothing works even though I've removed two things from the signal chain (the switch and a MDP extension cable). I decided to use a software AirPlay solution rather than a hardware switch, simplifying to a single connection to the Cinema Display. Swapping out the AppleTV 2s with AppleTV 3s didn't help either. And with our 35 ft cable run (a beefy 23 awg cable about 3/4" diameter), the Cinema Display wouldn't lock sync at 1920 x 1200.

Incidentally, Lupunus gives great advice (use one cable, avoid adapters and converters) that is unfollowable thanks to Apple. Since the AppleTV ONLY has DVI out, and the Cinema Display ONLY has mini-displayport in, and there is no HDMI source to MDP display cables (there are only MDP source to DVI display cables; HDMI source to MDP display requires an electronic converter).

Our next step is to move the AppleTV to the CinemaDisplay to see if it reduces the signal drop enough to switch the Cinema Display on. If that doesn't work either, we will have to take them in to Apple for the $400 repair/replace service.

I had a problem (i.e. past tense) with my 23” cinema display not coming out of sleep. I read multiple posts to find a solution. My problem was resolved when I changed my smaller iMac (not a solution I had in mind; it just happened) to a larger iMac (I forget sizing between the two).

Absent an Apple engineering fix, I believe people will need to find a ‘work-around’ from all those that have been posted in this discussion and others discussion boards on Apple’s site and in non-Apple technology blogs (just do a search via Google-it has been a long time so I forget).

For bkgd purposes, my CD is ~8 yrs old. I initially used with my ~8 yr old PwrPC laptop (which still works well, but is obsolete due to hardware). Two year ago, I purchased the smaller iMac to replace the laptop. One day (could have been a year later) the CD fails to come out of sleep. I concluded from reading discussion boards that it may be the ‘brick’ and purchased a used one.

Switching out the brick worked for a time, but I ran into same problem sometime later. After switching back to the old brick, I decided to keep the CD on constantly (i.e. no sleep mode, but had a screensaver come on).

Approximately 6 months ago I purchased the larger iMac and discovered that my CD comes out of sleep. Therefore, I conclude, there is not enough juice in some of the devices to kick the CD out of sleep, hence my belief that this is an Apple problem and should be solved free of charge by them.

I had a wake up problem with my display and I finally tracked it down to the energy saving settings after reading various websites. I finally found that the following definitely works.

Delete the following file and the restart your computer and the monitor comes back to life!

/Library/Preferences/SystemConfiguration/com.apple.PowerManagement.plist

I battled with this problem for months but by removing this file the monitor came back to life. Apple, why have you not fixed this problem? When I spend £600 on a monitor I expect it to work flawlessly!

Exact same problem as everyone else has described - monitor won't wake up after long sleep, usb still works but screen doesn't turn on ..eventually monitor would turn on after rage pulling the cable in and out... bla bla. I have a Macbook late 2009 (unibody), running on Maverick with a 24" LED Cinema Display (don't know what year).

Thank you Celestrium. Your trick *SOLVED MY PROBLEM*! I deleted the file just as you proposed and my Cinema Display has been worked flawlessly ever since. Yay!!!

Delete the following file and the restart your computer and the monitor comes back to life!

/Library/Preferences/SystemConfiguration/com.apple.PowerManagement.plist

A week ago, I upgraded the Radeon 1900XT graphics card in my ancient MacPro (made in 2007) using

an ATI Radeon HD 5770 Graphics Upgrade Kit for Mac Pro. This kit doesn't seem to be available from Apple but I found a source(OWC) for it.

For years I was experiencing the same sleep issues for my 23" Cinema display(display would not come to life either after a cold startup or after sleeping) and was pretty much resigned to restarting my Mac 3 - 5 times before the screen would show anything. The problem seemed to start after a system upgrade (can't remember when).

The new card seems to have solved that problem. After over a week of use and many sleep-wake cycles, there hasn't been one situation when the monitor didn't wake up. The solution seems to be in what the monitor is plugging into on the card but I'm not expert enough to know details of its inner workings.

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?

Thank you thank you thank you!

I have had a useless Apple LCD monitor here for two years. When I bough my new Mac Pro I had to buy a new 27" LCD screen as well as the previous one was too unreliable. I had quotes of hundreds of dollars just to look at it from the local Apple dealer and my wife wanted me to throw it out. I just never believed it was that far gone as it would work for a while perfectly then after a while would be totally black. Several days later it would work fine again for a while.

In countless tests I never fathomed out the connection to sleep and not waking till I tried again yesterday and saw it sleep and fail to wake up. Armed with that information I searched for 'Apple LCD won't wake from sleep' and found you post. Sure enough after deleting the .plist the monitor is good as new.

What is amazing is the same exact issue was happening on both MBPs I have and my nMP all upgraded to Yosemite. So it sounds kind of like a bug in Mavericks maybe that carried over to Yosemite? Anyone out there have a clue?

For those on Yosemite that see no such file, it will be created once you change settings in the Energy Saver panel in System Preferences. I honestly don't know if creating it will cure the problem if no such file exists or if creating then deleting after a reboot would. My guess is something was corrupted in the Monitor itself and a fresh .plist fixed it. Maybe even Yosemite and the deletion was needed? I just don't know but I do know my nMP looks pretty good with two Apple LCD screens now thanks to you.

Cheers!

5 years later and this is still an issue!