I have an HD satellite box which I previously connected to my old PC. I am interested in using my new iMac 27" 5K as a monitor for its output.
I did go through the various answers available, but some contradicted others, and many were outdated. Currently, I connected the box's HDMI cable to a Kanex Mini DisplayPort to HDMI adapter and then to the iMac, and as you can guess, it failed to recognize a second display.
Is there any way around it? Either by some software or a different adapter?