Hi, thanks for this info - helped me solve my problem.
On my stationary PC I have an NVIDIA card with TV out, and on the laptop an ATI Mobility Radeon 9600 with TV Out. I have a European vintage RF color TV - PAL (so of course in the display settings for both cards it was PAL that was chosen), so I got an old VHS VCR with a SCART connector to try and see PC video on the TV. I then got a kit consisting of a cable with S-Video connectors on both ends, and a converter with three RCA inputs (yellow for video and two for audio), S-video connector and a SCART connector. I connected S Video Out on PC -> S-Video input on Converter -> Connect via SCART to VCR -> from VCR to TV via RF.
The stationary PC would give TV image with color up to Windows boot, and then turn black and white. I found the same problem on some other forums, and it comes out that in the latest Nvidia drivers there is a setting where you can force whether the signal coming out of the tv-out is composite or s-video. I set it to composite as suggested and I got color afterwards.
Now the laptop on the other hand was a bit tougher - I tried all combinations provided by the drivers in displa settings, but still black and white. Many forums on the other hand point to the following page to adress that problem
http://www.tkk.fi/Misc/Electronics/circuits/svideo2cvideo.html
So, it seems that the Y and C signals in s-video are separated and go through two pairs of wires, whereas in composite Y and C are merged together and go through one pair of wires. And it also seems that these old VCRs can decode composite, but not separated s-video. So, the fact that the Nvidia gave color whereas ATI didn't, pointed out that ATI might not provide an option for setting composite video signal through the s-video connector - all it did was send s-video all the time.
Only after I saw it confirmed here, I got determined to cut the cable and patch it according to the above webpage. However, there was one nice thing in the kit that I bought (which was by the way noname, ultracheap, and packed in see-through nylon
) It was a converter consisting of a s-video connector on one side, and a male RCA jack on the other. And that is precisely what is needed - from two pairs of connectors to one - since one RCA jack carries a video signal, having one ground - then it must carry composite eventually, so this connector would have to actually patch both Y and C signal lines from the s-video connector together.
So I just connected the tv/out to this converter, the converter went into the video (yellow) RCA input of the SCART converter, SCART into VCR, VCR to TV and voila - color (though might not be as intense as from the NVIDIA)
Hope this might help
