Q: Using iMac as a display for Macbook Pro

Please carefully read Target Display Mode: Frequently Asked Questions (FAQ)

Sorry, however Apple has been very open about the Retina iMacs not supporting TDM. I suspect you just forgot to ask when doing your research.

Bernadette100 wrote:

 

I've also just tried it with an iMac 27" mid 2011 and it doesn't work there either.  On both displays, the background screen of the Macbook displays on the iMac but you can't see the icon or menu bars or navigate with either the mouse or the keyboard.

Is there some other trick to this?

Are you trying to use mirroring (same image on both screens) or extended display (separate images)?

And you enabled mirroring in System Preferences > Displays?

There are two mirroring-related options in System Preferences > Displays:

At the bottom of all tabs there is "Show mirroring options in the menu bar" which, as it says, controls whether the icon appears in the menu bar.

Slightly above that, in the Arrangement tab only, there is "Mirror Displays" which is the option that actually turns on mirroring.

Which do you have turned on?

If you have the options icon displaying, you can also turn on mirroring by selecting "Mirror Builtin Display" from the menu that drops from that icon.

The Arrangement tab is also where you tell the MBP how the iMac display relates to the MBP display spatially (to the right, to the left, higher, lower).

None of this is dependent on the external display being an iMac; they work that way with other displays.

I don't have an iMac to test, but I think the iMac's keyboard and mouse are supposed to "go dead" in Target Display Mode. It's acting as a display, not a display + keyboard + mouse. (I have read that it also processes its own background tasks.)

If you don't see an Arrangement tab between Display and Colour/Color, then the MBP isn't seeing the iMac as a second display at all.

"Air Display" is a non-Apple software to use iPad/iPhone as a secondary display. It is possible that it is interfering with the hardware function you are trying to use.

The icon that "Show mirroring options..." shows is an AirPlay logo (open rectangle with a filled triangle piercing the bottom line), even for hardwired external displays.

P.S. I'm calling it a night. Good luck with your issue.

Hi there,

i´ve red your posts carefully, but don´t found a answer to my scenario.

I own a iMac 27" (late 2009) with a mini display port and i just bought a MacBook Pro 13" Retina (early 2015) with the force trackpad. However, on my Macbook there´s only a HDMI and two Thunderbolt connector. Every 27" iMac since the late 2009 (not the 5K one) should be able to receive the video signal. HDMI to mini display port won´t work, i have tried it. Do i need a Thunderbolt (Macbook) to mini Display port (iMac) Adapter? I´ve red the apple-support-pages about the target display mode but i don´t understand how to connect the two computer.

i hope someone could help me out.

Thanks in advance

André

This table seems pretty straight forward:

See the list below for iMac models that support Target Display Mode, the type of cable you need to connect that model of iMac, and the kind of port you need on your other Mac.