Most TV's won't show you the option to switch to the HDMI input unless they see a signal from an HDMI connected device. Most likely the laptop's video adapter isn't set to send the video out through the HDMI port. Go into the laptop's screen resolution settings and change it so it's set to display on two displays, then try the TV. I don't know what operating system your laptop is running, or I could better walk you through setting up a dual-display in Windows. You should be able to find info on that by searching online though. Hope this helps.
http://www.tvasap.com
