I have a 2011 27″ iMac and a 2015 Macbook pro retina but when i try to use my iMac as a screen with target display mode (with thunderbolt cable and hitting command F2 on the iMac’s keyboard) it doesn’t work. Any sugesstions?

Target Display Mode 2011 & Later iMacs

iMac- How to use your iMac as a Target Display Mode display

Use Mac notebook computer in closed-display mode with an external display

I have the same question. Only with slightly different hardware.

My mid-2010 iMac seems to struggle loading OS High Sierra, so

I have down graded to Yosemite. It runs well doing that. Still, no

response on using the CMD + F2 to turn this display into 'Display

Target mode'. Any suggestions ? Thanks !

I had this problem and fixed it with a NVRAM reset. Also this doesn't work if the MacBook isn't directly connected to power source.

NB though I have had new problems since the latest High Sierra update and now it doesn't work at all (restarts my imac).

What adapter would I need to connect a new MacBook Pro to the Apple thunderbolt “27 display

Hi, I have the similar issue.. when I hite the command F2 the monitor in my mac work for a minute and shutdown... here in Brazil the Apple suport dosent fix it.. :(

Tatiana, I have the same problem. When I hite the command + F2 my monitor running for a minute hut after shutdown the iMac.. did you say ove your issue? Tha if you can share how here.. tks