I'm hoping that someone here can help me out as I have spent several hours trying to get my Apple TV to work. I have a Harmon 550 and I have my Apple TV connected to my Harmon Kardon receiver via HDMI. I did all the right setup making sure that the Apple TV was the media center. When I use the remote, it switches my receiver to Media center mode, turns the TV on and to HDMI and I can see the light on the Apple TV. However, I do not see any screen, just a black void. The Apple TV is connected to the internet via ethernet and my powerline system so I assume its getting a signal. I have also tried it out in wireless mode and still, no luck. Any suggestions or advice would be greatly appreciated as this is getting very frustrating.