Somehow I skipped it but I'm glad it made HN again, as I think it has an important clue I'm facing for at least couple of years with this Apple Thunderbolt Display - I'm using it with a HP Elitedesk 800 G4 with a Titan Ridge controller and a PCI thunderbolt card. Works great, except (1) I cannot suspend the computer and making it to turn off the screen, else it won't turn on again; and (2) and the most irritating one, at random times at boot, the screen will refuse to turn on. I've done all sorts of weird tricks to make it turn on but everything involved restarting the computer and never thought about unplugging/plugging the monitor again.

Thank you so much for the heads up and to the person who posted this again.