Function key won't work for that. You need to click on the 2nd monitor. Then look down at the bottom of that screen and do to things. Make sure that the resolution for it is the same as the 1st monitor and set it for Extended Desktop. This has to be done with the TV attached and on so the settings will stay. Last thing you may have to do if it doesn't come on at that point is right click on the 2nd monitor icon and "Activate" or "Attach" (can't remember which and my work system doesn't have that capability
).