iMac as 2nd display for MBP Retina

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iMac as 2nd display for MBP Retina

I'm trying to establish and use my old iMac (2011) (OS 10.10.5) as a second display for my newer MBP Retina (OS 10.11.4) by following these directions but they don't seem to work:

Follow these steps to start using your iMac as a display:

Make sure both computers are turned on.

Connect the Mini DisplayPort or Thunderbolt cable between the two computers.

Press Command-F2 on the keyboard of the iMac that you want to use as a display.

After you press Command-F2, your iMac displays the desktop from the connected Mac.

Those directions seem very straight forward and I've followed them exactly so I don't understand what I could possibly be doing wrong. Is there a problem with them?

MacBook Pro with Retina display, OS X El Capitan (10.11.4), 2.5 GHz 16MG

Posted on Apr 24, 2016 12:40 PM

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Answer 1

curly1 Author

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Apr 24, 2016 1:12 PM in response to curly1

clarify:

I'm using a Thunder cable adapter to connect with the Firewire cable. Would that make a difference?

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Answer 2

Duane

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Apr 24, 2016 1:37 PM in response to curly1

curly1 wrote:

clarify:

I'm using a Thunder cable adapter to connect with the Firewire cable. Would that make a difference?

Yes. You need to use a Thunderbolt cable.

Use your iMac as a display with Target Display Mode - Apple Support

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Answer 3

curly1 Author

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Apr 24, 2016 1:47 PM in response to Duane

Right- But will I need to keep the Thunderbolt to Firewire in place for the Target Display?

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Answer 4

Duane

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Apr 24, 2016 1:49 PM in response to curly1

No, you need to remove that. Not sure why you were using it.

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Answer 5

curly1 Author

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Apr 24, 2016 1:51 PM in response to Duane

Mainly because I was told I needed to-perhaps I should go back to my hippy days and question authority more often?

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Answer 6

Duane

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Apr 24, 2016 1:54 PM in response to curly1

By whom were you told that?

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Answer 7

curly1 Author

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Apr 24, 2016 1:57 PM in response to Duane

Really I forget who said that but it was somebody in this forum.

*

In any case I plugged in that cable and pressed Command-F2 on the iMac keyboard but nothing happened. Do I need to restart or something?

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Answer 8

Duane

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Apr 24, 2016 1:59 PM in response to curly1

When you say "that cable", do you mean Thunderbolt to Thunderbolt?

Use your iMac as a display with Target Display Mode - Apple Support

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Answer 9

curly1 Author

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Apr 24, 2016 2:01 PM in response to Duane

yes

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Answer 10

Duane

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Apr 24, 2016 2:02 PM in response to curly1

From the article I linked to above...

If Command-F2 doesn't work

If your iMac doesn't switch to Target Display Mode when you press Command-F2, check these things:

Make sure the iMac you're trying to use as a display supports Target Display Mode.
Make sure you're pressing Command-F2 on the keyboard that's connected to the iMac you want to use as a display.
In Keyboard System Preferences, if the checkbox is enabled for Use all F1, F2, etc. keys as standard functions keys, the key combination changes to Command-Fn-F2.
Make sure your Mini DisplayPort or Thunderbolt cable is connected to both computers.
If you're currently logged in on the iMac you want to use as a display, try logging out to return to the login window. Then press Command-F2 again.
Some older Apple keyboards and third-party keyboards might not allow Command-F2 to toggle display modes. If this happens, use the keyboard that came with your iMac to toggle Target Display Mode on and off.
If your iMac is currently started up in Windows, it won't enter Target Display Mode. Target Display Mode isn't supported in Boot Camp.

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Answer 11

curly1 Author

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Apr 24, 2016 2:17 PM in response to Duane

I'll look into all this after I finish "multi-tasking" (aka doing laundry!)

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Answer 12

curly1 Author

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Apr 24, 2016 2:58 PM in response to curly1

OK frustration is mounting here as I've followed the directions again and again and still nothing is changing.

The iMac has been used in TDM numerous times. And the Apple page confirms that this iMac (2011) will or should work for this.

I've tried the keyboard in both modes (with Fn and not) to no avail. And I'm now using the Wireless keyboard that was supplied with the iMac (I was using a third party keyboard before.) I've also tried the wireless keyboard in both modes as well.

It is Thunderbolt2 to Thunderbolt2 (Is that possibly a problem area-2 vs 1?) and I even tried switching ports (both on the MBP and the iMac) just in case one was bad.

I've also tried powering down both systems to rule out anything gone amiss there.

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