Using older iMac as second monior

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Level 1

9 points

Using older iMac as second monior

I have a mid-2010 iMac 27 I want to use as a second monitor with my mid-2011 iMac 27. I thought I only needed the Thunderbolt cable and set the second monitor to Target Display Mode. Nothing happens. The second monitor only displays the Target Display Mode symbol (Y). Command + F2 doesn't make any difference either.

I just read on the Apple site that maybe I need the Mini DisplayPort cable. Is that correct? Will both iMacs support that cable?

Or am I doing something else wrong?

Thanks.

iMac, OS X El Capitan (10.11.6), 16 GB RAM

Posted on Oct 1, 2018 4:16 PM

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Answer 1

Top-ranking reply

Malcolm J. Rayfield

Level 7

23,095 points

Oct 3, 2018 3:21 PM in response to Crash777

You will need to connect a keyboard to the old iMac to enter Command-F2 to start Target Display Mode. You could borrow the new iMacs keyboard for this, then return it to the new iMac.

https://support.apple.com/HT204592

After that you use only the new iMac's keyboard and mouse for both screens. In extended desktop mode you will be able to drag widows between displays.

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Answer 2

Oct 2, 2018 8:15 PM in response to Crash777

Use a Mini DisplayPort (M) to Mini DisplayPort (M) cable. Plug it into a Thunderbolt port on one computer and a Mini DisplayPort on the other computer. No adapter is needed. Thunderbolt ports work with Mini DisplayPort plugs (for video output only).

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Answer 3

Niel

Community+ 2026

Level 10

742,685 points

Oct 1, 2018 4:19 PM in response to Crash777

You need a Mini DisplayPort cable.

(164707)

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Answer 4

Crash777 Author

Level 1

9 points

Oct 2, 2018 4:47 PM in response to Niel

Sorry - had another question I hope you can help me with. The ports on the back of the 2 iMacs are different.

The mid-2011 iMac has 2 Thunderbolt ports, a FireWire 800 port and 4 USB 2.0 ports. I don't see a port marked as a Mini DisplayPort even though the specs say it has one.

The mid-2010 iMac has 1 FireWire 800 port and 4 USB 2.0 ports. It does have a Mini DisplayPort slot and the corresponding icon above it, and the specs say that's what it is.

Do I need a Mini DisplayPort cable and an adapter to connect the older iMac to the newed iMac?

Thank you!

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Answer 5

Crash777 Author

Level 1

9 points

Oct 3, 2018 9:58 AM in response to Malcolm J. Rayfield

Thank you. I'm getting conflicting answers as to whether or not a single keyboard and mouse can be used. If the older iMac is set as a monitor using Target Display Mode doesn't that allow me to move items from one screen to the other?

I have an HP laptop with 2 Dell monitors and they're connected using the extended display function. One keyboard and mouse works on either screen.

Thank you.

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Answer 6

Crash777 Author

Level 1

9 points

Oct 11, 2018 4:35 PM in response to Crash777

I plugged in the Mini DisplayPort to both iMacs. The second, older iMac does switch when I press Command+F2, but that's as far as it gets. I'm not able to move anything to that screen or access any of the desktop items.

Thoughts? I followed the instructions so I would think it would work, especially when the screen did switch.

Thank you.

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