27" led cinema display goes black

Thank you. I'll wait till it dead before buy one.. since also a single cable costs like a new "normal" monitor..

I may have found a solution to this issue. First, let me note a couple of things so anyone reading this can determine if it may help them. I have an older 15 inch MacBook Pro (about 5-6 years old) and an LED Cinema Display (27inch). I have it running the most up to date OS and all SW is updated. In fact, when I tried to update the LED SW and firmware, the system indicated that I don't it. Anyway, the monitor belonged to my wife, who was using it with no issues on her 6-7 year old 13 inch MacBook, and no longer needed it as I got her a new iMac with a big monitor. So, I inherited it. But when I plugged it in, just got black screen. There was definitely a connection as the screen on the MacBook Pro seemed to dim out and then come back. After reading about, in this thread, people jiggling the connector at the port, I had an idea (as the jiggling didn't work for me). I eased the connector out about an eighth of an inch, to where it was at the point where it was causing the laptop monitor to dim and lo and behold, the LED Cinema monitor comes to life. I've tried this several times. If I push the connector all the way in, black screen. As I ease it out, to just the right amount, it pops on, and stays on. After choosing the USB out put, from the sound preferences, the speakers in the monitor work too.

Now, I will say one thing. It is a little sensitive to lateral motion pulls on the cable at the computer port, so make sure there is no tension on the cable. With the cable partially pulled out, to make this connection work, it must experience more torque, due to any pulling on the cable, and that can cause a break in the connection.

I know this is not intuitively sound, but it worked. It's like plugging into a wall socket part way. It was as if the connector from the monitor (the metal parts that go into the port) are too long by 1/8 inch (give or take a 1/32) and you have to account to that by pulling it part way out. Anyway, try this as what's the worst that can happen? You may find the monitor is fine, which is why it worked at the store for some people who wrote in this thread, and you don't need a new one. Hope this helped.

PS. The port I was using was the monitor port, not the USB. I think it's what they call the thunderbolt port.

The Power supply has an outlet that goes to a connecter (not the mains supply ) that then appears to go to the screen. Is this the DC supply to the backlights and on a working supply what should the voltage be ...measured on the two contact points on the supply board? A1316 model.. I am not talking about the multi output connector that goes to the logic board. I have no backlights and I think the supply is faulty. Anybody help here ?

The Power supply has an outlet that goes to a connecter (not the mains supply ) that then appears to go to the screen. Perhaps this is a DC feed for Magna safe power outlet ???? ( not the backlights ) can any technician tell me which pins to check for voltage for the backlights?

I have answered my own question, The suppply is for the magnasafe adaptor It would seem that my screen which works perfectly sometimes for about 3 mins may have a fault on the logicboard that is fixed to the back of the panel. `I think this supplies a V sync signal that goes to the main logic board to enable the backlight supply. Does any body know where to purchase a replacement logic board that fits on the screen back?? Is the V sync signal just a steady DC voltage and which pin does it go to etc.. ? It is ridiculous that these faulty expensive panels cannot be repaired ... or is it will not be repaired.

I was troubleshooting this issue on my Thunderbolt 27 display and realized something that may help others. My screen was black and, from reading other posts, it seemed like it was either the cable assembly or the internal power supply. No amount of cable jiggling got the monitor to turn on so I was leaning towards the power supply. However, I noticed that the magsafe adapter from the monitor DOES work. Since power comes into the monitor from the power cord and then goes out a different cable to supply the magsafe adapter, I reasoned that power must be flowing through the monitor's power supply and that it was ok.

Then I noticed the standalone Thunderbolt port on the back of the monitor. I plugged the monitor into my MBP using a thunderbolt to thunderbolt cable and, low and behold, the monitor turns on! So, clearly, in my case the issue is the cable assembly and not the power supply. If the magsafe adapter ALSO didn't work, and the secondary thunderbolt didn't work, it would have more likely pointed to the power supply.

I hope this little bit of logic and troubleshooting helps others determine the cause of their issue.

"...the cable bundle connecting the Mac and the display. It seems to be a week link and they have already seen a number of other problems related to this cable."

Yeah, that appears to verify it for me, that's been my thought all along with mine going dark. I've gone for fairly long periods with it not happening but now the problem is bad. Mine did NOT start with flickering. It just goes out like there is no power to it. At this point I can keep on restarting and eventually it will light up. At one point fiddling with the connection to my power bar would bring it back. I didn't see this before around 4.5 yrs of having the display, though.

Possible Solution: Remove Display USB from Computer

We had the same problem. Our 2-year-old display would flicker two or three times then go black about 5 min after a restart. It would restart after you remove and reconnect the display and power cables. We took the monitor to the Apple store. Apple kept it for a day to troubleshoot and run diagnostics, but they couldn't find anything wrong and suggested that there may be something wrong with the computer's graphic card. We tested it on a separate laptop and had the same problem, so it wasn't the computer. I figured it had to be a power issue, so I played with different brightness settings--no difference, it would still flicker then go black after a while. Just on a hunch, I removed the display's USB cable from the computer. I figured that the apple techs probably wouldn't have attached it when testing-- lo and behold, it started working again! We've had it on for 3 hours now with no problems. Hopefully, it will continue to work (*fingers crossed*). I'm guessing that there may be a power issue with the monitors USB hub that is triggering the monitor to power down.

Hi folks...

I have followed this post and have been troubleshooting my 27" Cinema Display for years in regards to this issue of the display going black. Having been frustrated by lugging the thing in multiple times to Apple support only to find "nothing wrong with it;" having changed the power supply, the umbilical cable, and the CPU graphics card "just in case;" etc., etc., about 6-months ago I think I did something that has (so far) helped tremendously with this issue.

I was reading about power supplies, the destructive impact of transients and spikes to sensitive electronics, and the importance of providing high-tech displays with clean power supply waveforms... you know, a little light reading like everyone does from time to time. So, I decided to invest in a Pure Sine Wave Backup UPS system. To be clear, I did not go with a Simulated Sine Wave or other lower-cost alternatives, but with a relatively hefty $200-$300 unit. I must say that I have been very happy with the results and believe (qualitatively) that this may have solved the problem. The Display has been working seamlessly, quietly, and happily since I made this change. BTW, my computer is a 2010 Mac Pro 5,1 which cost $6000 at the time, so I don't think it was so unreasonable to expect a quality power supply to have been included! For completeness, I bought and installed the CyberPower CP1500PFCLCD.

Again, this is an evidence "n=1" so take it in the context of other experiences, but I for one am a believer. I was quite surprised about the impact because I guess I assumed that the original power supply in the computer or LCD would be designed adequately in order to address these issues and maintain high-quality operation. My understanding is that the AC supply coming to the house from regional power generators are just not very clean. Equipment transients, power transmission over long distances, and the likely pickup of significant noise along the way results in lightning strikes, voltage spikes, brown outs, and black outs. In particular, I have noticed that the brown outs happen relatively often and, although they are usually not powerful enough to shutdown the computer, you can definitely tell that there are voltage surges and variability in the power. The Backup UPS filters out all of that variability and provides in-line power right when it needs it so that the CPU and LCD don't see any changes. The sensitivity of today's high-tech equipment, I think, requires much more advanced power correction solutions than in the past and I personally attribute the significantly improved performance of my LCD Cinema Display to the Pure Sine Wave backup UPS.

Hope this helps.

Best regards,

Paras.

just updated to 10.10.4 and the problem seems to be solved. been working for 10 hours and my monitor has yet to shut off. it was happening every few minutes before.

hope this helps

t

Has anybody else tried using a UPS system and has it worked?

Also- did the update to 10.10.4 truly solve the problem (it hasn't gone black again)??

Thanks!

I Also have a 27 inch cinema display purchased in 2012. I had it on a Mac Pro purchased in the same year. I had the issue where the video would become unresponsive, whereas isight, sound, USB inputs were OK. After a reboot the problem was usually solved. The issue kept going for about a year and kept getting progressively worse.

At this point the video sometimes works for a few hours before going black.

I am wondering if this is a power issue with the unit? As mentioned, the other ports and functionality work fine with this display, except the video.

I have had a 27 In cinema display and had similar issues where the screen would go black since purchase in 2012. While still under warranty I took it to the apple service center and they found no problems on two occasions. Since then the issues have gotten progressively worse, where the monitor seldom lights up, except for a few minute after unplugging several times. After running through all known software issues, at this point I am almost certain there is a problem with either the backlight/led panel or the power board. Is there anyone with experience in diagnosing either of the issues with repair options?

Guys I HAVE to post this.

After suffering the same problems you described, leaving my 27" Cinema Display unplugged for 2 days and still having no joy, I decided this morning to remove it from my desk and connect an old 24" Samsung. As I carried it from my office and placed it gently on my bed I noticed a male power socket just behind the stand that I'd never seen before. Then I noticed that the 'captive' power cable had come away.

Here's the point - I believed the power cable was captive, part of the monitor, but it's not. Apple make a beautifully contrived, perfectly fitting circular collar that's molded onto the power plug so that when fully inserted it is absolutely flush with the back of the monitor.

I pushed the power lead firmly in, carried the monitor back to my desk, connected and everything works!

How did the problem start? I bought a a little monitor stand from Costco to raise the 27' display and when I pushed the whole lot back to the rear wall, it trapped the monitor leads, puling the power lead slightly out. Because my monitor has temporarily failed almost anytime I move it, I thought it was just the normal 'unplug for a day and it will be fine'.

Hope this helps somebody.