first i would try disconnecting the TV from the computer and boot up your computer after a complete system shutdown with only the monitor as the only display connected to your computer.
if you see nothing connect your TV back up. in the display properties or nvidia control panel you should see a setting to make a device either the primary display or secondary display. set monitor as primary. also to make it easier to see off the TV temporarily set your desktop resolution to a low size, 800x600 or 640x480.