So my laptop's screen broke a month ago and I've been trying to connect it to my TV via an HDMI cable. Both devices have an HDMI port.
My computer is an HP with Windows 7 installed. I'm not sure what my TV is, other than an Emerson. I've tried Fn + F4, and it didn't work. I can't see anything on my computer screen so I'm at a bit of a loss otherwise. :[
I tried it on my boyfriend's HDTV and it worked fine, just plugged it in and it came on. And yes, I'm on the HDMI channel.
go into "control panel"
on the side there is a "connect to a projector or other external display"
this will open a window with things like Display brightness
you'll want the "Display connected", hit Connect Display this should make the TV come on, or it did for me