Q: Display flashes to solid black intermittently

I've had my 27" LED DIsplay for  3 years now and just started having this trouble this morning. Flashes to black for the blink of an eye and then resumes. Flashes occur with no apparent pattern.

In my case I'm quite certain I heard a "pop" from the monitor first thing in the morning as it turned on after it had been off over night. I've skimmed most of the posts on this and I haven't seen anyone report any indication of hearing anything from the monitor during power on. In my case, I think its likely a blown capacitor.

Anyone hear a "pop" or a "click" like this? Any sucessful repair stories?

DMD137 - I've never heard a pop from any monitor, much less an Apple Cinema/Thunderbolt. I'd say you have a bigger problem on your hands than just flickering. If you can get it to an Apple Store, they are very good about making sure you end up with a working product.

Following up on my own post. This "pop" has recurred a couple of times today and following a rather loud one I'm now pretty certain that its coming from the speaker built into the display -- something is sending a burst of noise through the device. And I've noticed light "snow" when the screen is black. Off to service...

I too was noticing a kind of "pop" sound, though I'd thought of it as a click. It may not in fact be the same sound you heard. I thought it was coming from my LED Cinema Display, but it may have been from my external speakers (Logitech), which are behind the monitor. It always caught me by surprise, and I was never able to associate it with an event. But once after I'd forgotten to turn the speakers back on after returning the MacBook Pro to its spot and reconnecting everything, I realized I had not heard the sound. So I left the speakers turned off and disconnected from the MacBook Pro - and I have not heard the sound since.

In my case, I think this was associated with something bigger: the breaker for the circuit with the MacBook Pro, the Cinema Display, and the speakers (and some other things) was tripping with dismaying frequency - not quite daily, but more often than weekly. But since the speaker system has been off (a few weeks now), the breaker has not tripped again.

At one time, I thought the sound was associated with the blacking of the Cinema Display, but that stopped after I disconnected (and returned) the Belkin Thunderbolt Express Dock. Now I'm pretty puzzled about the whole thing.

If you find out anything taking it to service, please post.

Definitely not, just installed itunes on an HP Wondows 7 and it happened to me, so it might be itunes.

Following up on my initial post. My problem was the cable (display/USB/power trio) that connected my laptop to the monitor. I just had this replaced ($90 diagonstic, $90 parts and labor) and the snow, the flashes to black, and the audio pops are gone. A couple of notes that might help others diagnose if this cable is your problem too:

[1] The repair technician could not replicate this problem in his shop. I went in and the two of us spent some time trying different combinations of computers and displays. In the end we found that there was a certain bend in the display cable just near where it plugged into my laptop (pull it flat and forward) that could make the symptoms come and go.

[2] Upon reflection, this isn't surprising. When I plug these cables into my laptop on my desk they make a rather sharp bend toward the back of my desk where they then hang down. Apparently after 3 years of bending and hanging like this something inside broke. Upon one more reflection, I had a similar problem with an iphone cable a while back, although that one showed more visible signs of wear. Apple seems to like to build elegant, but fragile, cables.

[3] So I've rearranged my desk to try and keep this cable straighter. Here's a lo-tech strain relief strategy: http://lifehacker.com/5943071/keep-your-charger-cables-from-fraying-with-an-old- pen. The cable/laptop design does not make relieving the strain particularly easy. The cable has only about 10 inches from where the three cables join to their ends and the power is on one side of my laptop and the display port on the other. Some amount of bend is required.

I FIXED THE INTERMITTENT BLACK SCREEN PROBLEM

I managed to find a fix for this problem of the external Hewlett Packard display connected to my Yosemite iMac intermittently going completely black for a second or two (after which the picture retuned). These brief flashes to a black screen would occur once every 10 or 15 minutes, but sometimes they would be more frequent, appearing every 60 seconds or so.

I tracked down the problem to some LED energy saving bulb lighting that was plugged in to the same mains electric socket extension that my monitor was plugged into. Once I unplugged these energy saving LED lights, all those flashes to a black screen completely stopped.

LED energy saving bulb (and compact fluorescent energy saving bulb for that matter) contain electronic circuitry, and I think electrical noise from this lighting circuitry was affecting the monitor, via the monitor's power supply cable.

I also found that by plugging my monitor into a surge protection adaptor plug would prevent the electrical interference from the energy saving lighting from affecting the monitor and causing the flashes to a black screen. The surge protection adaptor plug seems to isolate the monitor from the energy saving lighting, and so using this adaptor I find I can plug both my monitor and the energy saving lights into the same mains socket extension without experiencing any problems.

So for anyone experiencing these problems, with their monitor intermittently going completely black for a second or two, have a look at what  energy saving lighting or other electrical items you have plugged into the same power socket as the monitor, and see if removing these electrical items fixes your problem.

I FIXED THE INTERMITTENT BLACK SCREEN PROBLEM

I managed to find a fix for this problem of the external Hewlett Packard display connected to my Yosemite iMac intermittently going completely black for a second or two (after which the picture retuned). These brief flashes to a black screen would occur once every 10 or 15 minutes, but sometimes they would be more frequent, appearing every 60 seconds or so.

I tracked down the problem to some LED energy saving bulb lighting that was plugged in to the same mains electric socket extension that my monitor was plugged into. Once I unplugged these energy saving LED lights, all those flashes to a black screen completely stopped.

LED energy saving bulb (and compact fluorescent energy saving bulb for that matter) contain electronic circuitry, and I think electrical noise from this lighting circuitry was affecting the monitor, via the monitor's power supply cable.

I also found that by plugging my monitor into a surge protection adaptor plug would prevent the electrical interference from the energy saving lighting from affecting the monitor and causing the flashes to a black screen. The surge protection adaptor plug seems to isolate the monitor from the energy saving lighting, and so using this adaptor I find I can plug both my monitor and the energy saving lights into the same mains socket extension without experiencing any problems.

So for anyone experiencing these problems, with their monitor intermittently going completely black for a second or two, have a look at what  energy saving lighting or other electrical items you have plugged into the same power socket as the monitor, and see if removing these electrical items fixes your problem.

Fixed!

Updating the cinema display firmware as described in this article seems to have worked for me. I had the flashing problem very frequently but have not seen it at all since updating the firmware.

LED Cinema Display (24-inch, Late 2008): Intermittent flicker while connected to a Thunderbolt port - Apple Support

Anyone else with this problem and solutions? I've had this blinking problem on and off for a couple years. Would annoy me for a week and then calm down for months. Now it's been happening for a week and is starting to get really annoying. It's a Mac Pro 1.1 and an hp 2335 via DVI. Went from a x1900 to a radeon 5770 with the problem still occurring and from 10.6.8 to 10.7.5. Thinking of maybe getting another cable or an adapter and using the mini display port. It's hard to troubleshoot since it is so random.

I have tried everything and this last attempt is working for me. It used to happen 2-3 times an hour. Now it has been 100% for 5 full days. I installed  SwitchResX software ($20) that overrides some display settings. If it returns i will post it here. SwitchResX

I use my system for Live Events and Projection Mapping.

Mac Pro (Late 2013)

2.7 GHz 12-Core Intel Xeon E5

64 GB 1866 MHz DDR3 ECC

AMD FirePro D500 3072 MB

Apple Thunderbolt Display

27-inch (2560 x 1440)

Where is the 30" cinema display firmware?!? Why on earth is there no solution after this issue was raised more than 3 years ago?!? This Apple arrogance is staggering. I now have to part with my cinema display as I can't live with this flickering anymore.

Mac Pro 4,1; NVIDIA GeForce GT 120; dual HP 24 inch monitors.  Had the same intermittent black blinking, very regularly (it would affect both monitors simultaneously).  Reading this post made me think to try relocating the monitor cables away from power cords and USB cables.  Having done so, I haven't seen any blinking for two days now.  I'm hopeful that this cheap solution will solve the problem for good.

Same issue... Just started late 2015 macbook pro

Same problem here on 27" Display, Mac Pro (late 2013), AMD FirePro D700.   I have a dual monitor setup and it's only happening on the left one.   Tried moving cables around in back so nothing is touching.  See how this cheap fix goes...