My Nvidia video card will not connect to my old "standard" television! What do I do!?

I did this a few days ago with an ATi card and setup was a cinch, I simply plugged it in and the video card automatically detected the S-video to RCA hookup and worked fine. I need the same thing to work with my Nvidia PC and I'm not having any luck. Even after screwing with settings and what not, I cannot get the TV to get any signal from the PC. It may or may not matter that the S-Video to RCA converter I am using came with my ATi card. Thanks for your help.