That if HDMI handshake fails you need to unplug it all, remove power from the TV and take a short break. Come back and try again.
I have a 2 year old samsung LED 40 inch TV. I had Sky installed today and could not get the TV to accept the sky box via hdmi. Last used the hdmi connection about a week ago to connect a laptop but now that does not work either. TV states no signal on any of the hdmi sockets although they do go darker when the cable is plugged in. Any ideas?