help me please needing to connect it

[musso4]

i brought a new laptop today and brought a hdmi cablei have a lg tv and i cant work out how to make it work on my tv and i havehad the cable plugged in and the screen on my laptop gose black and my tv screen stays the same wat do u need tofix to stop the screen going black ?????????????????

 

[musso4]

need to get help to fix the problem just wanting to know why my screen is going black thats all