You haven't stated what type of card you have.
If there is a yellow plug (or socket) on it, like used for DVD players and consoles, wouldn't you plus a DVD player or console (or cable decoder box) into it?
From what I understand;
- you have a video in card
- the card does not have any tuner
- the card has a composite video input
- you've plugged your cable source into it
If this is how it is, then it certainly won't work, it's just not designed to, but I've made a lot of assumptions.
Could you be more specific?
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