1 Reply Latest reply: Jun 19, 2013 9:52 AM by mario49
sflomenb Level 1 (40 points)

Hi, not sure whether or not this belongs here or in the iMac section. Regardless, I have a new MacBook Air and I am trying to use my 2009 27" iMac as an external display. I have a MiniDisplay connector plugged into both. When I press Command-F2, my iMac's screen goes dark, and my MBA's screen goes blue.

MacBook Air (13-inch Mid 2013), OS X Mountain Lion (10.8.4), 8 GM Memory, 512 GB
  • mario49 Community Specialists

    Morning sflomenb,


    Thanks for using Apple Support Communities.



    For troubleshooting on this, take a look at this article:


    Intel-based Macs: Resetting the System Management Controller (SMC)




    A computer that supports target display mode does not switch into or out of target display mode as expected.





    For more information on this, take a look at this article:

    Target Display Mode: Frequently Asked Questions (FAQ)



    Make sure both Mac computers are turned on and awake.


    What are the requirements for TDM?

    • A Mac notenook or desktop with a Mini DisplayPort or ThunderBolt connection
    • A ThunderBolt or Mini DisplayPort cable 
    • A supported iMac with OS X 10.6.1 or later.




    Best of luck,