Thunderbolt Display turns off randomly

Steve, I have tried everything you and others have suggested and more. Most recently, I tried a Thunderbolt dock (which I needed now that my display won't serve as a dock - in order to connect to an extra monitor and use my Thunderbolt drives at the same time. My TB display is totally dead now, I've tried it about 20 times with different configurations and absolutely nothing happens. It is a real shame.

I have tried everything that you say in the forums , I called Apple , no way . I'm pretty frustrated, this monitor is crap.

I think this may be an answer for some. The cable at the fitting where it connects to the computer can have a very tight turn depending on your setup. I think when the cable is bent tightly at this point it creates resistance and heat build up. Try adjusting the cable so that the turn is very gradual and rounded. Over time I suspect that the cable also becomes a little compromised from being bent tightly. Still keeping the bend very gradual and open seems to help a lot. My display would go black after only a few minutes and connecting and disconnecting the cable would get it to work for only a short time. By rounding off this angle it is not going black at all. At least for this evening. Try this and see if it works. I would be interested to see if this works for others. If it does work it really indicates the cable is not manufactured properly since it cannot take this amount of bend.

Well the fix above worked for a little while and now fails. Back to Apple we go. The first time they just re-seated the cables and that did not fix the problem.

Very sorry to hear that.

Since I abandoned the use of the fitted cable and reverted to using a separate Thunderbolt cable (Mac Mini to Display via Thunderbolt sockets), mine has been running just fine. It's been over two months of uninterrupted use now. Phew!

It just started happening with my monitor too. Interesting, that if I disconnect the TB cable and connect it again, the display turn on for several seconds and then turns off again. I've managed to switch setting to "never turn monitor off" and this make it work now. It looks to me like software/firmware bug, not a hardware failure.

Actually, no, ignore my previous post, it still happens. Now I'm trying to use a separate cable.

Obviously this problem persists for lots of people. Here's my story:

- About a year after purchase, the TB display would not wake from sleep. The genius at the San Francisco Apple Store first tested my MBP for a couple of days then tested the TB display. Conclusion: there was a "motherboard" issue in the TB display so that was replaced under AppleCare.

- The TB display worked well for several more years, but during the past several months, it began to black out suddenly. It would come back on with a restart of the MBP, but then I found that unplugging the TB cable caused the TB display to come back up.

- After several more weeks of periodic unplugging/replugging, the TB display began to flicker periodically before it would shut down. The TB cable routine stopped working reliably, but unplugging/replugging the TB display's power cable brought the display back up.

- Eventually the frequency of the black-outs made the display unusable. I found this thread and purchased a separate TB cable that connects to the back of the TB display. This seemed to work for a week or so, but then the flickering and blackouts returned.

- I have also tried the "prevent monitor sleep" setting, but this does not prevent the TB display from blacking out. At this point, the TB display is unusable.

From this I conclude that none of the nostrums suggested by people so far actually fixes this problem. Relieved people who think they've dodged the bullet will presumably find that the problem comes back to haunt them soon. There is something fundamentally wrong with this monitor's hardware, firmware, or software. It's just a matter of time until this gets us all, which is a real shame, since the display was gorgeous while it lasted.

I think your conclusion is correct. Absolute fundamental firmware issue - my last with Apple as I will never purchase a monitor from them again, and maybe never anything from them. My $1,000 paperweight was a lesson that Apple is not the company it used to be.

My conclusion so far is that in most cases the cable is the faulty component. The connectors contain built-in chips that becomes quite hot after some time. And after 2 years of intensive use these chips become unreliable. The solution for this is to replace that cable or to use the other cable connection option. For most people that will be the external cable option.

I used the external cable connector from the very first beginning, so had to replace that cable after 2 years. I replace my white cable with the new black variant, just to be sure that it contain the newest firmware. Until today (nock, nock) no issues.

A new TB cable purchased from an Apple Store did not fix this problem for me. I don't believe that it is a simple cable issue. Congrats for your current improved situation, but I suspect your problems will return.

My story is very similar. During my first year with my TB display I experienced these issues with random black outs. It was repaired under the AppleCare and I have since learned that the estimated cost of that repair was about equal to what I paid for the display in the first case. A couple of years went by without any trouble at all. And then this spring I started to get black outs again. Infrequently at first, then gradually more and more often. The pull-the-power—cable-routine worked for a while but this is not helping any longer. A new TB-cable has been tested as well, but to no avail.

Don't hold your breath. This is a "fix" that has been tried by many and found lacking (including myself, who has tried the newest cables, even a thunderbolt dock with two new cables). The cable fix worked for a very short while for me (about 3 weeks) and then it all went south . . . once again. I hope it does continue to work for you though, I don't wish this issue on anyone.

I'm sorry to read that the cable fix doesn't work for you. It's working for me since November last year. But still, it's the most troublesome piece of hardware I have from Apple. The power supply produces sometimes a weird rattling noise, the USB connections are unusable to connect the Apple keyboard, and the need to replace an expensive cable with a new one is of course quite absurd.

I had the same issue - very frustrating. Tried a number of things, no luck.

My "fix" for the blinking, then blank screen on the Thunderbolt was finally to just unplug the display connection to my Mac Book Air (not the power.) I then give the computer a few seconds to recognize the disconnect, it sets to the size for the built in screen, then replug in the Thunderbolt. I have to resize some open software on the screen, but now I have no more problems - sometimes for days at a time.

Works for me.