Thunderbolt Display Power cuts off

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Level 1

10 points

Thunderbolt Display Power cuts off

Hello,

Hoping someone else can offer some insight to my issue. I have a 27" Thunderbolt display that I connect to a 15" Macbook Pro running 10.10.4. I have had the display for 2 years and it has been great until now. I use the magsafe to magsafe 2 adapter, and everything has worked just fine until the last 2 months.

Now, the whole display looses power randomly. It acts as though it has been completely unplugged. I can unplug the power cable and plug it back in, which sometimes works and sometimes does not. When that does finally work, the display works normally until it looses power again, seemingly at random times. It happens when I am working, and when I just plug the laptop in to charge. I have tried it plugged straight into the wall, thinking that it was the UPS, same issue. Sometimes it stays on for an hour, sometimes just a few minutes. Any ideas about what the problem could be? Is it toast?

27" Thunderbolt Display-OTHER, OS X Yosemite (10.10.4), Magsafe to Magsafe 2

Posted on Jul 29, 2015 7:09 AM

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Answer 1

tbirdvet

Level 6

13,689 points

Jul 29, 2015 10:34 AM in response to ashbus

Sounds same as this:

Thunderbolt Display turns off randomly

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Answer 2

ashbus Author

Level 1

10 points

Jul 29, 2015 1:02 PM in response to tbirdvet

The last time it happened I removed the Thunderbolt plug from the Mac Mini and reinstalled it and this fixed the issue.

Sounds similar, but unplugging and replugging the thunderbolt plug from the laptop does nothing because there is no power going to the display. I have to unplug the power cord on the wall and plug it back in to get it to come back on. Sometimes that does not work either.

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Answer 3

tbirdvet

Level 6

13,689 points

Jul 29, 2015 4:13 PM in response to ashbus

If you get a TB cable you can connect from your Mac directly into the TB port of the display. If it works then your integral TB cable is bad. If it does not work then your port on your Mac is bad or the Display has an issue.

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Answer 4

ashbus Author

Level 1

10 points

Jul 29, 2015 7:22 PM in response to tbirdvet

Okay, good suggestion. I will try that. I don't get any power through the charging cable from the display either though. The power also disconnects from the USB ports because my Wacom tablet and my external drive turn off. Maybe it's an issue with the main power cable then? Can you use a regular monitor power cable to test it, or does it have to be Apple?

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Answer 5

tbirdvet

Level 6

13,689 points

Jul 30, 2015 5:24 AM in response to ashbus

If you mean the main power cable to the wall then using another non apple cable will work as long as the connection is the same at the display. I would not expect that cable to be bad.

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Answer 6

ashbus Author

Level 1

10 points

Jul 30, 2015 5:37 AM in response to tbirdvet

I tested the main power cable to the wall by replacing it with a regular power cable. As you expected, that was not the issue either. This is disappointing. I love the display when it works!

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Answer 7

ashbus Author

Level 1

10 points

Aug 4, 2015 3:30 PM in response to ashbus

Okay, I am marking this resolved for now. I took the display to the Apple store. The nice folks there kept it for two days and left it on. It never turned itself off there, and they could not recreate the situation. I brought it home today and it has been on since noon with no issues.

For anyone else with this or a similar issue, I suggest unplugging it, packing it up, driving 40 miles to the Apple store, and leaving it there where it will magically work just fine for two days and also when you bring it home. Alternatively, maybe just unplug it for an hour or so and then plug it back in...

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Answer 8

ashbus Author

Level 1

10 points

Oct 22, 2015 5:18 AM in response to ashbus

I have found the answer to my issue. It is the magsafe to magsafe2 adapter that is causing the problem for me. As long as I use the macbook charging cable instead of the monitor's power cable with adapter, everything is good. I thought at first it might just be a bad magsafe adapter, but after purchasing a new one, and having the same result, it is clear that the adapter is the issue, at least with my particular machine.

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Answer 9

emo59

Level 1

0 points

Oct 25, 2015 12:48 PM in response to ashbus

My Thunderbolt display has done this same thing twice now. What you posted worked, I unpluged it and waited an hour and it came back up. I first noticed the light on the under side of my mouse, so I knew it was getting power. Before, no signs of power at all. I was allready looking in my attic for the original box to pack it up, so thanks. I hope this doesn't become a regular problem.

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Answer 10

bluz1st

Level 1

4 points

Jan 11, 2016 12:11 PM in response to ashbus

I have this problem too...........periodically.............

The workaround...........UNPLUG the power cable that goes into the center back of the monitor..........do not unplug it from the monitor.........unplug it from the main power source (wall outlet/power strip/battery backup whatever) and then plug it back in........I do this even though my laptop is still attached to the monitor via thunderbolt cable.........brings the monitor out of sleep mode/inadvertent power down every time (so far anyway). Obviously Apple has a problem here with these monitors, they do not seem to be taking responsibility for it, fixing it or replacing these monitors for their customers would cost them a fortune I'd guess............TOO many people are complaining/having this problem for it to be some random thing.

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