Have you tried to enable video out on the second adapter, either with Fn F8 or Ctl Alt F2 (Ctl F3 to cancel)? I know it is kind of like asking if it is plugged in, sorry
I'm having the same problem. Did you ever figure it out? The laptop does not seem to be detecting the TV as an external monitor. When I hit Fn+F8 I only get my laptop display as an option.