Dark TV-Out problem with Radeon 9700 PRO (GigaByte)

Hi!

I've got a problem with my video card. Recently, after reinstalling windows,
I'm getting crappy dark and oversaturated TV-out on my Sony TV. I've tried
different drivers, and different S-VHS cables. It used to work perfectly
with bright colors and clean output.

I've flashed the BIOS on both motherboard and video card, and it didn't make
a difference. I've physically removed the card and re-inserted it to no
avail.

I haven't done anything that could physically cause this, at least not as
far as I'm aware. I've tested this during boot, and all the BIOS readouts
and POST reports are similarly dark and oversaturated. I fear I've fried
something in the card, but can't imagine what would have done that. I've
tried other computers with the same TV and cables, and the output is fine.
I've read about people having this same problem after reinstalling windows,
but they haven't been able to resolve it.

Any ideas please?

Regards

Michael Albertsen