tv screen monitor very black/dark

[guido.coza]

Hi all
I turned my LCD TV into a monitor. However it is very dark with a very harsh contrast. I am sure it has to do with a display setting , but all attempts of going thru the different settings do not change a thing. Also my brightness (F2) is "locked". please help

 

[Bigwaff]

I turned my LCD TV into a monitor.

What brand model of TV and how are you connecting to it? USB? HDMI? If HDMI, version supported by TV vs version supported by HDMI cable?