HDMI stopped working

When I connect to the TV using HDMI the TV recognizes that something was connected but the computer does not display on the TV screen and the TV says there is no signal. I know that the TV recognizes the connection because HDMI 2 on the TV is not available until I connect the computer to HDMI 2 and then the words HDMI 2 lights up on the TV. I have tried multiple ways to make the computer picture go to the TV by connecting many times without success. I thought maybe the cable was bad so I connected my a Dell using HDMI and everything was fine.