Late 2009 iMac won't work as Target Display Mode for Mid 2012 MBA

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Level 1

8 points

Late 2009 iMac won't work as Target Display Mode for Mid 2012 MBA

Hi guys,

I know this question has been asked a lot, all with slight variations of the same problem, but maybe (just maybe) there might be a specific solution for my particular problem.

Anyway, late 2009 iMac 27" (2.66 GHz i5) and a Mid 2012 MacBook Air 11" (1.7 GHz i5). Both running OS X 10.8.4, the iMac has a miniDisplay port and the MacBook has a thunderbolt. Using a thunderbolt cable to connect the two. I first tried them just connecting without any reboots, pressing cmd+F2 and nothing happened at all. Tried again in the specific boot order (as has been mentioned elsewhere in these forums), whilst connected and again nothing happened. On reading other posts it appears that others' intended TDM iMac may flicker and then go back to square one, but mine does nothing whatsoever.

So, what am I not trying? Or will are these two machines incompatible for Target Display Mode?

iMac, OS X Mountain Lion (10.8.4)

Posted on Jul 28, 2013 10:09 PM

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Answer 1

mende1

Level 10

93,538 points

Jul 28, 2013 10:29 PM in response to DreKlei

Welcome to Apple Support Communities

As the iMac has got Mini DisplayPort, you have to use a Mini DisplayPort cable because the iMac won't detect a Thunderbolt cable > http://support.apple.com/kb/PH11302

You have to buy a Mini DisplayPort cable in Internet, like this one > http://www.amazon.com/Belkin-Mini-DisplayPort-Cable-meters/dp/B0032ANCIW

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Answer 2

DreKlei Author

Level 1

8 points

Jul 28, 2013 11:58 PM in response to mende1

Thank you for the response!

I would like to point out this line in the support page you just linked me too:

If you have a 27-inch iMac with a Mini DisplayPort, any other Mac with a Mini DisplayPort or Thunderbolt port can use it as a display.

If I'm reading this correctly, then it should work? My 27" iMac has a Mini DisplayPort, and the 'other Mac' has a Thunderbolt port. If I were to purchase a a regular Mini Display Cable, then the macbook wouldnt recognise it, correct?

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Answer 3

mende1

Level 10

93,538 points

Jul 28, 2013 11:59 PM in response to DreKlei

If you have a look at that website, you will see that you need a Mini DisplayPort. Thunderbolt is compatible with Mini DisplayPort, so it will detect the Mini DisplayPort cable without any problem.

That means that the Thunderbolt cable doesn't work as the iMac doesn't detect it, but the Mini DisplayPort cable works because the MacBook detects it

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