Have you upgraded your Laptop to Windows 7, and not able to connect to your TV using S-Video? Here is how I solved that problem with my laptop.
I recently upgraded my old laptop to Windows 7 from Windows XP (I never believed in Vista, and had skipped it). Before upgrading, I was able to easily connect my laptop with my TV using S-video. However, after I upgraded to Windows 7, it was not able to detect my TV.
I browsed through lot of forums, but no luck. Then I found one which mentioned that I should simply try updating my Nvidia drivers. I was almost sure that I would have latest drivers. Still I chose to go to Nvidia’s website. Nvidia has a nice tool that will scan your PC to automatically detect your Graphics card, and will also tell you if you have the latest drivers (download here). I installed that tool and it showed that I actually do not have latest driver installed. It even provided download link for latest Nvidia drivers. It was quite a big download (> 120 MB), but once I did that my laptop was able to recognize my TV.
So, if you have Windows 7, and your laptop stops recognizing your TV via S-Video, follow the steps above. This might just fix your problem too. If you want to check other drivers also on your computer, check one of the free driver updation software like: DriverMagician, SlimDrivers, and DriverIdentifier.