Any hope for S-video 9400GT (HTPC)

[xwin78]

I built a HTPC hack that is GREAT, except there is a fly in the ointment: when I went to hook it up to my TV via s-video composite adapter, after booting through the "APPLE" loading screen I got black screen. Unfortunately s-video is the best I can do on my aging TV ( 5years old). I dumped the video bios from my 9400 GT and built a custom EFI string with the proper NVCAP value using nvFlash /NVCAP maker / OSX86tools, and still have the same problem.

Any suggestions, beside getting a new TV?