Comment 8 for bug 318184

Using the --set command from jcdutton's comment works; xrandr then reports that the S-video is connected. I can then use the Display tool to enable the display and extend my desktop onto it. But the TV display starts out with a hash; you can see ghosts of the main laptop display sprayed across it and a lot of other garbage. Dragging a window from the main laptop display over to the TV display seems to draw correctly, and moving the window back off the TV leaves a correct background drawn in place, except for the rightmost ~200 pixels or so. Those remain a ghost trail of the window that was dragged over.

Interestingly, dragging the movie player over to the TV and then switching it to fullscreen mode works fine. But when exiting fullscreen mode, the same rightmost ~200 pixels are still garbage.