BNC Help/TV unclear..

I there,

I have a Old plasma tv that has the following connections on the back
of it.

Audio Input (R and L) red and white RCA cables
Video Input (BNC Connection) *i am assuming yellow RCA cable
S-Video Input
Component Video (3 BNC Connections) Y, Pb/B-Y and Pr/R-Y
RGB Input
RS-232C

Now I am trying to get a clear cable picture to this unit and having
trouble. I seem to only get it using my DVD/VCR combo with the Audio
Red and White cables along with a BNC adapter to Yellow for Video.
However, the picture is very fuzzy and I don't get that plasma feel.
Looks like an old 13 inch color tv.

Is there an easier way? any suggestions to make this unit into a
better plasma?

Thanks,

Chuck

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