Black screen with music icon

I've installed my Apple TV yesterday and works just fine, but today when I tried, the device turned on with a black screen and the music icon (the red one) and a white cable from the Apple TV to the music icon. I have no idea what these means and any thing that I try to do with the remote doesn't work, after a while the screen desappears and stay all black on the HDMI channel. What's wrong?! I already tried to disconnect and connect again but the screen reappears!