S-Video has suddenly stopped working, can anyone help?

[KnickKnack]

I play movies etc on my PC, and watch them on TV via an S-video cable.
It was working fine last week, but stopped working a few days ago. The lead is connected properly both at PC and TV. The TV is showing a black screen, no sign of the desktop screen that should be there

I have a regular non-HD TV, windows xp, geforce 8400.

I have a long wet weekend ahead of me.
I have a sick/tired 5yr old.
I need would like to play a movie or 2 tomorrow

[KnickKnack]

anyone?
Its driving me potty, can't figure it out.

[KnickKnack]

I may have to bump this thread all night