I have an HP laptop and a panasonic tv. First time I used the HDMI cable, it was instant sucess. Then the gremlins set in ( prob me trying to figure out out what the NVIDIA control panel could do ) there was no laptop display on tv.
My answer was to open the NVIDIA control panel (Graphics ) from right click on desk top.
go to "set up multiple displays"
then if you are lucky the name of your TV should be in a box waiting to be selected.
select and follow instructions:
RESULT! perfect sound and vision from laptop on the tv screen.