Dell inspiron 15 5000 screen is black

I have a problem on my dell laptop with screen. When I connect hdmi cable i see my desktop and everything is fine,when I disconect cable,screen is black. I didn't use my lal top maybe a month at all,and it was connected with my tv on hdmi cable,I leave it like that,amd I remember that i messed up some settings about that,but I don't remember what I change,since that dipley doesnt work by itself,only when it is connected on other display,like tv or external monitor. I can't go to bios,can't install new windows,can't do resset or system restore,I turn it off when I install windows. Can somebody help solve this problem. I try some settings,but it doesn't work,and I don't know what to do it is totally black screen.