I have found that the audio that comes out ofthe HDMI port on the X1 box soemtimes does not sync correctly with the HDMI iput to the TV. I see this over and over with the X1 remote box. I have never been able to get this resolved "on purpose" with the remote on the X1, but I can switch HDMI inputs on the TV, and move the HDMI cable from the X1 box to a new input on the TV, and switch the TV to look at that input. It will do a new-auto sync and set itself up to get the audio from the HDMI from the X1. Works every time for me. When the X1 gets "blithered" by a power cycle, most of the time it gets confused and when it comes back up, I get good picture and no sound. I switch to a different TV Iinput, and everything works fine, until the next power drop and the X1 goes down. Then I repeat the process, and it works fine.