So, plugged in new 4K Apple TV. Went through the set up process fine using my phone to set it up (very clever!). Got to the menu page and downloaded Netflix and Now TV apps. Went into settings and turned on homeshare as I wanted to use my phone as an extra remote. I was halfway through putting in my password and the screen went black - now I can’t get the picture back! Device still has a light on. Tried unplugging and plugging back in. Tried resetting with the remote. If I plug my old Apple TV into the same cables it works fine. Tv seems to recognise that an Apple TV is plugged in (it says it in text at the top of the otherwise black screen). Any ideas what is going on? Why did it work fine and then lose the picture? Tv is HD not 4K if that makes any difference. Any advice welcome - thanks.