Every once in a while when I plug in my MacBook Pro to my Thunderbolt Display and then press some keys on my external keyboard (laptop lid is closed) to wake it up, the computer won't wake up properly. The screen will either stay black or I will see a black screen and the beachball mouse cursor.

If I open the laptop lid in this situation nothing changes. If I then unplug the monitor nothing changes either. The laptop display is blank.

The only thing I can do at this point is to hold the power button until the machine turns off and then turn it back on.

This seems to happen about once or twice a week.

I'd rather not wipe the machine because it will take a while to reinstall everything.

Any ideas how to prevent this from happening?


  • MacBook Pro (Retina, 15-inch, Mid 2015)
  • OS X El Capitan 10.11.6
  • Have you tried plugging in the power? Have you tried hitting the keyboard on the computer itself as opposed to the external?
    – JBallin
    Commented Mar 8, 2017 at 20:01
  • Yes, I have tried unplugging the power and the display and opening the lid and hitting the keyboard on the laptop. The screen stays black or I will only see the beach ball. I have waited up to 5-10 minutes and nothing changes. Commented Mar 8, 2017 at 20:03

3 Answers 3


For me upgrading to macOS Sierra resolved the issue. I tried resetting NVRAM and SMC but that didn't help.

Update 8/2/2018: turns out this issue is still happening to me now, just much less frequently, about once every few months.

  • That's great! Glad macOS Sierra resolved this for you. :)
    – Monomeeth
    Commented Apr 13, 2017 at 1:49

As a starting point it's worth actually resetting both your NVRAM and SMC.


Older Macs had what's called Parameter RAM (PRAM), newer Macs use Non-Volatile Random-Access Memory (NVRAM). To reset this on your MacBook Pro, follow these steps:

  1. Shut down your machine. Yes, a full shut down, not just logging out.
  2. Using your built-in keyboard, press the power button and then press the commandoptionpr keys. You have to make sure you press these keys before the gray screen appears or it won’t work.
  3. Hold those keys down until your MBP reboots again and you here the startup chime.
  4. Let go of the keys and let your MBP reboot normally.

Note: When you log back in you may need to readjust some of your system preferences (e.g. speaker volume, screen resolution, startup disk selection, time zone information, etc).

Reset SMC

Your computer's System Management Controller (SMC) can also be reset. The instructions for resetting the SMC on your particular MBP are as follows:

  1. Shut down your MBP
  2. Keep the MagSafe adapter (power cable) plugged in.
  3. Using your built-in keyboard, press at the same time shiftoptioncontrol (on the left side of the keyboard) and the power button
  4. Let go
  5. Turn your computer back on with the power button.

Let me know what change in behaviour you notice (if any) upon rebooting.

Also, it may be worth you reading Use your Mac notebook computer in closed-display mode with an external display.

  • Thanks for the advice but this didn't help. You can see my answer for what did help. Commented Apr 13, 2017 at 1:11

i had the same issue with one of my thunderbolt displays, tried many options, non worked, until i found out that the power source is the problem (as in power fluctuation in the current), so use a very good "smart surge protection power board", that will solve the problem.
Same with the mouse you have to use a "full alkaline battery" otherwise if the voltage falls below1.5v it will discount intermediately.

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