You need to select from the TV menu of options that you plan to use HDMI-1 as your port or the -2 or -3. Then, connect the cable it to the PC. Then at the PC, select if applicable from its video manager setup that you want the TV as monitor 1 or 2(select the proper one). -OR- verify that the video card menu specifies HDMI as the video port to use. In many cases this isn't "auto-selected" you the user have to do it. What is your current PC monitor now and what port is it using and how many ports?