Using an older Imac (2013) for a second monitor on new Imac (2020)
I have followed every instruction that Apple has about connecting my older Imac, (late 2013) 21.5 inch to my 27" 2020 Imac. I have the Thunderbolt cable 3.3 ft, as well as the newest adapter which is the USB-C allowing the connection from the Thunderbolt 2 cable to the new Imac. I restarted both machines, and did the Command+F2, nothing. The screen is supposed to go black and come back on as a monitor only. It does not. The older Imac is running Catalina, the new is running Big Sur 11.2.1. What am I doing wrong??? I really need this second monitor. I also tried using my older Cinema screen, that also will not work. I have the original keyboard for both machines. Any other suggestions??? Thank you!