Hi all, Would love some help. I have a retina 15" Macbook Pro (mid 2014) and am attempting to connect it to a 27" iMac (late 2009) in order to use its target display mode. I've connected it with a Mini Displayport to Mini Displayport cable. Once connected I am pressing command+F2 on the iMac which makes both screens go black, however it cannot seem to create the required connection for display. Is there a step that I am missing here? Any help you could give would be greatly appreciated. Cheers.