Well, I've been in touch with tech support and still no luck. Has anyone else had this problem? Not sure why it won't connect.
I need to try this on my Vizio 42". I am guessing that if you close the Chromebook, it still goes to sleep?Turns out to work with the 1920x1080 Samsung over HDMI after all. When first connected, it behaves as I described. The "secret" is that you have to hit CTRL-Fullscreen(F4). That will stop mirroring, blanking out the C7's screen and going to full resolution on the external monitor. Hitting the key combination repeatedly cycles though; display only external, display only internal, mirror, ... Good to know.