When I added HD service to my X1 box today the Xfinity person advised my slave box would also be capable of showing HD broadcast channels. The service was added successfully to my main X1 box
but when I tied the slave box TV it would not display full screen HDTV only a smaller rectangular pictue filling about 75% of the screen.
Thanks for your help
Thank you for your reply.........yes the slave box is connected to the TV hdmi input
Andrew I just noticed the channel lineup in the guide with the slave unit does not display any HD tier (800-900) except for 834 and thats displayed in in about a 75% size framed in a black bacground.