I have a mid-2012 Retina MacBook Pro and two Thunderbolt displays purchased in mid-2014. The MBP sits plugged into one of the Thunderbolt displays almost all the time, unless I'm using it away from my desk.

Lately, I noticed that the computer's charging behavior was odd:

  • The menu bar's battery indicator did display the "charging" lightning bolt;
  • The percent charged number did not change over the course of many plugged in hours;
  • The indicator light on the MagSafe charger did not turn on.

Some power was clearly coming through, since the battery was not draining; it was just also not charging. Restarting did not solve this, and neither did resetting the SMC (my go-to move for weird power or peripheral glitches). But: plugging the laptop into the other Thunderbolt display did solve the problem.

Thus it seems there's a problem with that particular Thunderbolt display. How do I troubleshoot it?

  • 1
    Swapping the MagSafe adapters worked - now both cables are operational again. However I'm leaving this open in case anyone knows more about why that's the case, since my explanation is "??????".
    – hairboat
    Commented Dec 2, 2014 at 18:17
  • I have the same issue. The MagSafe adapter is likely bad. I went to the Apple store yesterday. They will not replace the adapter without a receipt, which I have not been able to locate.
    – Bowen
    Commented Dec 2, 2014 at 19:46
  • I had some clients at my work with the same issue. Sending the displays to our technical service got them repaired. I'm not sure, bit I think one client had a display our of warranty and it got replaces by Apple as coulance.
    – Jules
    Commented Jan 7, 2016 at 7:17
  • Same issue here with a thunderbolt A1407 and an original cinema display. Flipping the adapters did seem to improve things but it's not 100%. Commented Nov 15, 2016 at 12:55

6 Answers 6


I just did what AdamJ said, took my magsafe adapter off and clean it up with a toothbrush to remove dust. It really worked and now my thunderbolt display is charging my macbook pro! :)

  • 3
    This did not solve the problem permanently. Actually, I've came up with another workaround, which is pretty odd. Every time this happens I take the adapter out and flip it 180 degrees and put it back, it works again! This worKed EVERYTIME I did it! It sounds like a magnetic problem around it. Commented Jul 5, 2016 at 13:54
  • When I try flipping the connector, it does not always work though sometimes it does. I also try simply disconnecting and reconnecting (either the adapter or the laptop). Today I was able to get it working by using a different adapter, then going back to my usual adapter. Commented Jul 5, 2016 at 14:36
  • I can confirm this! I have two adapters and sometimes I switch them and it works, sometimes don't! Pretty weird Commented Jul 5, 2016 at 14:38

I had the same problem here. Reset the SMC and it fixed problem for ½ a day. Then back to not charging. Although the Macbook Pro indicator did show a charger connected, it just wasn't charging the battery and there was no light (amber or green) on the magsafe power from the Thunderbolt display. Another magsafe external charger gave the same results. Swapped the little magnetic magsafe adaptor with my wife's magsafe adaptor and now the light glows amber and my Macbook is charging again.


I've just recently started having the same issue with my 27" cinema display and a MacBook Pro (Retina, 15-inch, Mid 2014). Flipping the magsafe adapter didn't seem to work consistently for me. Plugging in the regular power adapter worked fine.

For me, cleaning the contacts with some isopropyl alcohol on a q-tip seemed to do the job. Might not be a long-term solution but so far it's doing the job.

  • So the above solution only worked temporarily for me. Got a new adapter and consistently getting power now. Commented Jan 15, 2018 at 20:38

Experienced the same problem recently. Took the magsafe adapter off, blew any dust from the inside and replaced. Works now.


I had the same problem after returning from a trip to Europe this morning. It was solved by plugging in the wall adaptor, which took a couple of seconds to start charging. Then the macbook air did start to charge after plugging it back into the thunderbolt display. The wall adaptor seemed to reset the charging circuit in the MB Air.


Having similar problems. Swapped Thunderbolt 30" displays, didn't fix it. Using the portable power adapter, the MBP charges. Once it's charged, we can switch to the Thunderbolt magsafe adapter, and the charge more-or-less holds (losing 1-1.5% per day), but won't increase unless we connect the external power adapter again. If the user goes mobile and then comes back to her desk, she has to use the external AC adapter to get her battery fully charged again, then can switch to the Thunderbolt display's power connector.

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