I have bought an S-Video cable so as that my old TV can be used as a second monitor, for watching iPlayer etc. I have an S-Video to Scart adaptor for the TV, Ubuntu knows there is a TV there and has set the correct resolution, but the TV shows no Picture??
NVIDIA GPU-based graphics cards with a TV-Out connector can use a television as another display device (the same way that it would use a CRT or digital flat panel). The TV can be used by itself, or in conjunction with another display device in a TwinView or multiple X screen configuration. If a TV is the only display device connected to your graphics card, it will be used as the primary display when you boot your system (i.e. the console will come up on the TV just as if it were a CRT).