27" Cinema display turns off randomly

This has happened to me as well. I now have had 2 go bad. The first I took back to the apple store only to have them tell me that it wasnt repariable and was out of warranty. So... I bought a new one and now about 2 years later this one is doing it too. I replaced the power supply today ($250) and still have the problem. Anyone get this fixed without changing the resolution of the display? I didnt pay top dollar for a monitor to use it at less then native resolution.

I had the same problem. The 27" Cinema Display would turn off automatically after 5-10 minutes. On turning the power off and then on again, it would come back on - if not at the first try, then at least on the second or third attempt. Additionally, sometimes the display brightness would fall significantly sometime after the display had come back on. But if the display brightness did fall, the monitor would stay on thereafter and work without any problem for the whole session! Now every time I sat in front of the computer I started wishing that the display brightness would automatically fall. This went on for a year, and out of frustration I was almost on the verge of sending it back to Apple for recycling.

Then only a couple of days ago I found that if I turned off the auto-brightness setting and manually decreased the brightness to about 3/4th the full value, then the monitor would stay on and never turn off automatically! It has only been a couple of days, but I haven't had the display turn off automatically since. Maybe this can solve the problem for some - if of course working with the reduced brightness is an option.

It seems that while the problems people in the forum are reporting are very similar, they are not exactly the same. For example, in my case reconnecting the mini-display port won't have any effect, and I haven't seen anyone else in the forum reporting an automatic drop in brightness. So don't get your hopes up, but do try manually setting the brightness to a lower value once and then see if the problem persists. I have visited this thread many times in the last year looking for hope and help. I hope this trick help you. Thanks!

Took mine to Apple. They replaced power supply and some other logic board component. Worked better for a while. Problem came back. Then, once I eliminated the use of a surge protector the problem went away for an extended period of time. But the issue is now present again. Won't easily come back on after power cycling. Used a power cycle would help. Annoying. This is clearly a known defect based on numerous reports here and other support threads. Mine is still under Apple Care. Going to politely demand a new Display at this point. Last time I was without it 5 days while they worked on it.

It works! Not shure, if the hard-plug-out after the new brightness setting has influenced the result. Today in the morning I turned on my Mac Mini, which is connected to the LED Cinema Display and it turned of after about 10 Minutes by itself as the last few days ago. Than I found the fix here. So I connected to the mac through Teamviewer, I changed the brightness-settings as mentioned and I restarted the display by just plugging it out and in. Now it works fine. THANKS A LOT!!!!

This is what worked for me:

The touch-sensitive power and brightness buttons on the side were randomly self-activating, causing the screen to dim, brighten, and shut itself on/off. I disabled these buttons through the display control panel. Now the screen stays on. This also disables the brightness function keys on the keyboard so I just have to use the control panel to adjust brightness, which is a little bit of a pain.

My issue was definitely with the monitor. I ended up taking it back to the apple store and they swapped it out for a new one. Problem hasn't happened since. So, it could just be a faulty monitor.