Want to use a 2010 imac as second screen with 2017 imac

[Al H]

Hi, new here, go easy on me...

I've got a 21" mid 2010 imac and a 21" 2017 imac and would like to use the 2010 as a second screen for photo processing and stuff. I got a mini display to usb-c cable and plugged it in but cmd+f2 doesn't work on either machine. I read that the 2017 machine doesn't support target display but the 2010 one does. Is there a simple fix or shall I just put the 2010 back in the box and forget it?

Cheeeeeeeerrrrrzz

Al

 

[CoastalOR]

I've got a 21" mid 2010 imac and a 21" 2017 imac and would like to use the 2010 as a second screen for photo processing and stuff. I got a mini display to usb-c cable and plugged it in but cmd+f2 doesn't work on either machine. I read that the 2017 machine doesn't support target display but the 2010 one does. Is there a simple fix or shall I just put the 2010 back in the box and forget it?

According to Apple's instructions, the 2010 21" iMac does not support Target Display Mode:

Use your iMac as a display with target display mode - Apple Support

Target display mode is a feature available with certain older Mac models.

support.apple.com