I have a Samsung UN65JU7100F 65" whose specs say it will support 3840 2160. I have the Belkin High Speed HDMI 4k cable the Apple store sold me as compatible plugged into HDMI port 2/DVI input. When I try the 4k SDR modes in 60 and 50hz the TV screen goes blank so I have to do the reset on the Apple TV by hitting the Menu and Vol Down button for 5 secs. Anyone have any suggestions? Thanks.