I have a new 2012 MacBook Air (just a week old). Today I tried to connect to an external LCD projector, using a mini-DisplayPort-to-VGA adaptor, to project my slides.

Something went wrong and I was unable to project. My Mac detected the external projector, and I was able to mirror my main display, but nothing showed up on the LCD projector, despite trying two different mini-DisplayPort-to-VGA dongles. In the end, I was able to successfully project from a different, older Mac using one of those dongles, so I don't think the dongle is broken.

What should be the troubleshooting procedure, if this happens again? Does the new 2012 Air require any sort of different procedure or equipment for mirroring your display onto an external projector?

5 Answers 5


In a pinch, this usually works:

  1. Connect your computer to the projector and turn the projector on.
  2. Restart your Mac.
  3. It should now work.
  • 1
    Yes restarting with everything plugged in works BUT that's not feasible for a teacher on the go. Any other fixes?
    – user28130
    Aug 27, 2012 at 18:57
  • 1
    You should never have to restart a computer to get this to work. (Sometimes it's a quick fix, but that's crazy annoying to have to do.)
    – Cajunluke
    Aug 27, 2012 at 19:28
  • Rebooting may work, but as others say, it's a sucky workaround that pretty much kills the use case of projecting from your MBA. After doing a bit more background research, it appears some sort of bug was introduced into the Apple drivers in one of the last few releases. It appears that the bug has been present for a few months with no resolution yet. I guess we wait for Apple to fix it.
    – D.W.
    Oct 16, 2012 at 21:40

The recommendation I received was to open a call from "bugreport.apple.com" and hope that this is fixed in future updates of the operating system.

  • 1
    Feel free to link to the bug report that you filed and flesh out how you considered this to be a bug if you intend that to stand alone as an answer. Thanks for the tip - It's almost more of a comment than an answer at this point.
    – bmike
    Oct 24, 2012 at 13:23

Pressing CommandF3 should cause the display to show.


I often encounter this problem. I found out that unplugging and reconnecting both the adapter from the MacBook and also from the projector cable makes the projection work again.


Go to System Preferences > Display > then click on Mirror.

  • 1
    The question also asks for troubleshooting procedures, could you edit your answer to match these if possible?
    – Munesawagi
    May 6, 2016 at 20:58

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .