There is a S-Video out at the back of the notebook. I tested it the same way as the second display, but the BIOS setting has no influence on the output. The screen contents are not shown, even not when booting.

If I use the Fn+F5 key kombination, screen and TV are totally distorted. And it works only in 640x480 and 800x600, other resolutions give no picture on the TV.