I have a 2014 Emerson tv when I hook laptop up with HDMI cable it only plays sound and the pic is of my main computer screen a

[bginn0325]

HDMI will hook up but no pic only sound

 

[hang-the-9]

Sounds like you did not move the program you are using to play things to the TV screen if you see your computer screen on the TV. Just drag the window over to the TV.