Can't get any of my Macs to run a second …

Can't get any of my Macs to run a second monitor

Someone please help!

I have an Early 2016 MacBook, a mid 2010 MacBook Pro, and late 2012 iMac. I have purchased every adapter and cord reasonably expected to work. I have a Thunderbolt Cable. I have a Thunderbolt 3 to Thunderbolt 2 adapter. I have a Thunderbolt to USB-A cord. I have a USB-C adapter that can connect to HDMI, USB-A, and USB-C. I watched tutorials, tried to enter target display mode on each device, plugged the adapters into all the right ports on each respective device and I still can't run two screens between any of the devices.

Is this truly an impossible task or am I missing a key step?

iMac (21.5-inch, Late 2012), OS X Yosemite (10.10.5)

Posted on Nov 13, 2017 9:25 PM

Posted on Nov 14, 2017 2:38 AM

First the Macbook and Macbook Pro cannot be used as a target display, the iMac can be used as a target display for a computer with Thunderbolt. The MBP doesn't have thunderbolt so it's out. To use the Macbook with the iMac you need a Thunderbolt 3 to Thunderbolt 2 adapter and a Thunderbolt cable. In Keyboard System Preferences, if the checkbox is enabled for "Use all F1, F2, etc. keys as standard function keys," the key combination changes to Command-Fn-F2.

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

Assuming the cables and adapters are quality products you can try resetting the SMC on the iMac How to reset the System Management Controller (SMC) on your Mac - Apple Support

Make sure you're inserting the TB cable correctly, they will go in upside down and not work.

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