Have you had any luck?
I have a mid-2009 Mac book pro 15" plugged into a 27" cinema display. I notice the same kind of issue. Unplugging it and then plugging it back in usually solves the issue, but often only for another 15 minutes or so. The issue has become worse. When the screen "blacks out" the led indicator on the magsafe power cord to the laptop also goes out. It seems to me that this is some kind of internal power regulation issue in the display. This monitor was replaced for the same issue about 14 months ago and ofcourse... now the replacement is not under warranty any longer... any thoughts anyone?
Laptop and additional monitor:
MacBook Pro late 2009 running Lion 10.7.5, updated
LED Cinema display, 24 inches, Late 2008 NVIDIA GeForce 9400M 256 graphics
The LED display started flashing off & on (to black -- it's not the alert flash, which is turned off in sys prefs). Changing monitor resolution did not fix it. Shutting down and re-seting the video cable plug did not fix it. The laptop display is not affected.
I restarted and reset PRAM multiple times. The on-off blinking continued for several minutes while I started to research the issue. Now, as I am writing this, I realize the blinking stopped after about five minutes or so.
I didn't notice the power light flashing.
What might be going bad? Is it in the MacBook video driver, or in the Cinema display?
Here was the solution for my issue, hope it helps:
I have a mid-2009 Mac book pro 15″ plugged into a 27″ cinema display. The screen would routinely “blank” out or shut off. I would no that when it did the green power life on the mag-safe power connector would also turn off. Unplugging the display followed by plugging it back in usually solves the issue, but often only for another 15 minutes or so. Then the issue became worse and would only function for 30 seconds or so before shutting down again. It seemed to me that this was some kind of internal power regulation issue in the display. I saw some posts online that this issue can be caused by a fauty cable set that plugs into your Mac. Apparently for some, if you move the cable set just right, the screen would work again. That was NOT the issue for me. I ruled that out in my troubleshooting by keeping everything perfectly stationary until the screen went blank. Once it did, I used the power switch on the power strip the cinema display was powered by to cycle the power to the display without touching the cables on the cinema display. My display would come back on for a little while which led me to believe there was a power supply issue.
I purchased the the “new” version of the power supply, part number 661-5543, from the DV Warehouse website. I think it was roughly $145 when I bought it. When I finally got around to completing the repair it was fairly easy. Obviously there are no directions with the part, but you can follow the dissassembly process on the iFixit website and simply replace the power supply board with the new one rather than putting the old one back. The process was fairly easy if you have even a little mechanical/electrical skill. You need a suction cup to pull the screen silica off and a star bit screw driver. I don’t remember the exact size star bit but it was a common size.
Note on power supply -
There is a NEW part number from apple that I used above (661-5543) which replaces the original part… Though this is common, it does make wonder whether the original design is faulty or otherwise less superior than it should be…
I have a problem where occassionally I will reconnect a 15" Macbook Pro to my 27" Cinema Display and it stays black and seems unresponsive to the power key on the right side of the ACD. Sometimes attaching a different MBP seems to get it to wake up, but not always.
But I just found something that cleared this recurring pesky problem for me immediately.
My symptoms: I'd untether my Macbook Pro (MBP) from my Apple Cinema Display (ACD) and use the MBP standalone for a while. Later I would hook it up again to my Apple Cinema Display (ACD).
Normally, it would go back into 2 monitors mode and the ACD would immediately show the 2nd screen. However, occassionally, the ACD remains black even though the Displays tool bar menu indicates it sees the ACD display as well as the builtin display -- however the ACD remains black -- and insensitive to turning on and off the ACD Power button on the right of the display.
My Solution: I go to System Preferences, select Displays and then go to Arrangement and enable the Mirror Displays mode, so I can see the ACD panel.
Now that I can see the ACD panel, I go to Options. Under "Display Power Button" I find that the menu item selected is "Turns the display on and off" is checked. That might be what I would like, but it isn't what is happening! So I click "Does nothing" to disable the button. Suddenly, my ACD shows the mirrored display in all its glory!
Now I go back to Arrangement, and turn off Mirroring again. Now my display remains on Whenever it is connected to a MBP.
I hope this helps others. I suspect that something confuses the internal software of the ACD so that it is ignoring the Display Power button (as is the case with "Does nothing"), but it thinks it is in "Turns the display on and off" and in the "off" mode. But since the Display Power button is a toggle and it is ignoring it, it remains stuck in the off mode.
Anyway, clicking "Does nothing" helped clear the situation for me. I hope it works for you.