I have two 27" iMacs and would like to use one of them as an extended display. All of the research I have done, including on the Apple website, says that all iMacs from Late 2009 onwards are capable with this feature. The two iMacs I have are Late 2009 and Mid 2011 models (see below/attached).
I have purchased a mini display adaptor cable and when I connect it between the two computers the Late 2009 iMacs screen goes blank and the Mid 2011 iMac screen momentarily shows the connection (in the display settings) between the two computers. After approximately 5 - 10 seconds the connection drops out.
I have tested both computers individually from my MacBook Pro (Mid 2014) using the Mini Display cable for the Late 2011 iMac and Lightening cable for the Mid 2011 iMac and they work perfectly.
This is very frustrating as all forums and support websites say this should work. Please help.
I have purchased a mini display adaptor cable and when I connect it between the two computers the Late 2009 iMacs screen goes blank and the Mid 2011 iMac screen momentarily shows the connection (in the display settings) between the two computers. After approximately 5 - 10 seconds the connection drops out.
I have tested both computers individually from my MacBook Pro (Mid 2014) using the Mini Display cable for the Late 2011 iMac and Lightening cable for the Mid 2011 iMac and they work perfectly.
This is very frustrating as all forums and support websites say this should work. Please help.
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