I have no problem using my iMac mid 2011 as monitor for my old Macbook Pro (2017, macOS Catalina 10.15.7) using a Thunderbolt 3 - thunderbolt 2 adapter.
However, it doesn't work if i plug my new Macbook Pro (2020, macOS Big Sur 11.0.1) into the same set up.
The ports on the Macbooks are identical and using the same exact set up.
Could it be bc of the 2020 mac is running a later software?
MacBook Pro
No, it is because Apple dropped TDM from all 2020 Macs early last year. The TDM support article is now archived so not fully up to date, plus it's poorly written, so here is a condensed version that incudes newer products:
VIDEO SOURCE COMPUTER (the one sending the video signal to an external monitor):
TARGET COMPUTER (the one to be an external monitor):
Apple started the deprecation of TDM in 2014 (!) and threw the last shovel of dirt in its grave is early 2020.
No, it is because Apple dropped TDM from all 2020 Macs early last year. The TDM support article is now archived so not fully up to date, plus it's poorly written, so here is a condensed version that incudes newer products:
VIDEO SOURCE COMPUTER (the one sending the video signal to an external monitor):
TARGET COMPUTER (the one to be an external monitor):
Apple started the deprecation of TDM in 2014 (!) and threw the last shovel of dirt in its grave is early 2020.
It's not the version of MacOS, it's the version of MacBook Pro.
MacBook Pro up to 2019 will work.
The feature is NOT supported in 2020 MacBook Pro and later.
Use your iMac as a display with target display mode - Apple Support
.
Thanks! Guess I'll have to buy a HDMI monitor and use with thunderbolt - HDMI adapter, as I hope that feature is still supported.
Can't use iMac as monitor for new MacBook?
