24 inch LED cinema Display momentarily goes black

Wow, this just started for me this morning. Got into the office, plugged in the computer, and weird blackouts. I disconnected the connectors from the computer, and then disentangled the display's combo cable from other wires. After plugging the connectors back into the computer, no problems. I had also had a power brick near the computer this morning, and moved that as well. So far, so good.

had a chat with Apple's Support who, after checking that everything was up to date, suggested the following:

SMC reset:

i) shut down the machine
ii) hold down SHIFT + CTRL + ALT then 'briefly' press POWER button
(i did it for about half a second)

followed by PRAM reset:

i) hold down ALT + CMD + P + R then press and hold down the POWER button
ii) hold the keys down until you hear the 'chimes' for the second time

it might be a bit premature to get excited about it but, after seeing the problem quite regularly today, i did this about an hour ago and haven't seen the problem since then

Hi everyone
I had a Macbook Pro 13.3" with Apple led cinema Display 24" for 7months with no problem, 2 days ago i changed my macbook pro for a macbook air and my screen started flashing black, Sometime 1 per hour sometime every 3 minutes. If i use the original mag safe that came with the macbook air the screen is not flashing and if i use the one that is attach to the screen, its flashing. Try to use your original Magsafe adaptor and let me know, Thank you

Same problem. I'm on a new (late 2009)15" MacBook Pro connected to a 24-inch LED Cinema Display. The screen goes black every once in a while for a second. No distortion or anything, but it's puzzling.

Have been having this same issue since last firmware update. I have 24" Apple Cinema LED connected to 13" aluminum MacBook (pre-MacBook Pro 13) Using display cable. My boss also has the same problem on his. His was purchased much later than mine and has been doing this from the start. He is connected to a Mac Mini and so is not using the pass-through power. Discussed one afternoon with local Apple Store and they haven't heard of the problem. Asked me to use my iPhone to shoot video of issue 😟 This clearly seems like a firmware issue. So.. here I wait for the next update, trying not to let my coworkers that love their Dell computers know that I'm suffering in silence.

I'm having this problem now too and have been with seemingly increasing frequency for a few weeks.

When it happens I can usually unplug and replug the mini-display adaptor and it will again turn back on. But typically not without having to muck with the display preferences system settings.

I did a SMC and PRAM reset yesterday and it just happened again.

Here's the specs:

LED Cinema Display:
Resolution: 1920 x 1200
Pixel Depth: 32-Bit Color (ARGB8888)
Main Display: Yes
Mirror: Off
Online: Yes
Rotation: Supported
Connection Type: DisplayPort

same problem here as well. 24" LED Cinema Display attached to MBP (15") shows frequent and random blackouts for a second or so. just attached a second identical display (brand new) that i purchased (for home office that i never set up). will see (and hope) & keep you posted.

I'm just chiming in to say that I am having the same problem with my two week old 24" Cinema Display and my MacBook Pro (2009 15" model). Specifically, my display will blank out momentarily (for a second or two) at random times -- sometimes more than once per hour but then sometimes not for over an hour. It also occasionally shows large bands of random pixels across the display horizontally for a split second. This second behavior has very rarely occurred.

I did try the SMC and PRAM reset suggested earlier in this thread but the intermittent trouble continues. The problem occurred both before and after the recent Cinema Display firmware update.

Update: I finally took my display into Apple on 4/9/2010.. Just got it back today 4/23/2010 (last day of my warranty BTW). They said that they replaced the logic board in the display, tested and did not experience the blackout or flicker. I had it back on my desk for no more than 1hr and THE PROBLEM IS STILL THERE!! Unbelievable!!! So.. The wait continues.. and in the meantime, I will urge anyone and everyone that I know: DO NOT BUY AN APPLE 24" LED CINEMA DISPLAY!

Just to complement the info from others.
I have two 24" Cinema displays (work and home). One (work) flickers once in a while (interval of days, hours or minutes), sometimes badly or even completely messes up with no apparent logic. Replugging the mini display cable solves the problem. The other one is perfect. Given the messages in this forum I did not even bother to contact Apple. Maybe a cabling problem or problems with the power lines? Annoying but I decided not to worry anymore. It would be nice to have a solution for otherwise perfect products.
I installed the firmware update on both but that did not change anything.
I decided not to exhange them between the two locations given the info on this forum. That does not seem to matter as replacing the computer and or screen ended up with the same problems (info on this forum). Power line filter? I will try if the problem ever gets worse.
I spend 8-10 hours in front of those screens per day and they are just the best I ever had. I will check this forum once in a while!

I bought a 24 Cinema Display. It experienced the black flashes and horizontal shifts. Would work fine for a while, but once it started flashing, it would do so frequently until for some reason it would just stop. I did the SMC and PRAM resets, to no avail. Switching to the better video card also did not help.

So, I exchanged it for another and this one works fine. Nothing else has changed, just the display. I do not use any adapters. I'm plugging it into the same plug that the first one was plugged into.

Therefore, it must be a hardware problem occurring with some ACD's. If you are experiencing the black flashing and/or horizontal shift, I would contact Apple and arrange for a repair.

This is an update to my previous post about this 24" Cinema Display problem with my 2009 MacBook Pro. I have now discovered that the problem occurs only when using the lower power graphics support. The problem does not occur with the higher power graphics chip. (This is the setting in System Preferences > Energy Saver > Graphics: Better Battery Life vs. Higher Performance.) I've switched back and forth several times and worked for hours in each mode to verify that it only happens when running with "Better Battery Life".

This problem still needs to be fixed since I usually want to run my system with better battery life but hopefully this can be used as a clue as the source of the trouble.

I purchased 2 apple 24" LED cinema display about a week ago and just got them yesterday. I tested them with *iMAC, Macbook Pro, MacBook* but have not yet test it with *Mac Pro*. They seem to work fine for me. I was very worry about this screen black out problem but I decide to purchase them because I believe that it's not because of the screen but it could be the performance of graphic card and the interruption of the signal.

I did some research before I bought these and found that the *Mini-DVI is very sensitive* to many thing around the machine area. It could easily get signal interfere even by using a strap to keep your wire organize and tidy. I'm not sure that this is the exact thing that cause this endless problem but it worth to try to keep anything that could interfere the Mini-DVI as much as possible. I did and they seem fine. I thought this might help.

I'm also going to test with Mac Pro via using the *DVI to Mini-DIV convertor* too. I'm waiting for the product to arrive now.

With a Dell 30" monitor on my Mac Pro and Radeon X1900Gt video card. Just started in the last few days. Blacks out momentarily and then comes back on. Tried switching to different resolution and back again. A temporary fix seems to be to switch the monitor off and then back on again and it behaves for the rest of the day. I am also on 10.6.3. The only thing I can think of is that I installed QT7.6.4 in the last few days but other than that nothing has been changed.

Hi all.

I have 2 x 24" LED's hooked up to my Mac Pro with Radeon 4870. One of them today just started going black for a second. Only thing is, it's doing it every 15 - 20 seconds 😟 It's the monitor plugged into the mini display port.

They have been working fine for 6 months. Now all of a sudden, this. 😟

What should I do?