"Input Video Formats 480i , 480p , 720p , 1080i"
You'll need to use 720p at first since it's not 1080p on the inputs.
You should also use HDMI.
I have Windows 7 Enterprise installed on my Dell laptop. When I connect it to Samsung 46" LCD TV using VGA and press Fn+F8, my TV gives the error "Mode not supported". I have already tried playing with the settings in screen resolution and changing the resolution for TV & laptop separately.
However when I connect the same laptop to a Samsung 22" monitor, I can extend the display without any issues.
Dell Inspiron 6000 - 15"
Screen Resolution: 1680x1050
Intel Pentium R 1.66GHz/2 GB RAM
Display: ATI Mobility RADEON X300
Can someone help in this regard?