S-Video jack gives poor connection

[George]

Oxidization could be the problem. Contacts tend to get dirty. Go to an electronic supply shop and buy a can of contact cleaner. Spray it lightly on the male pin side and carefully plug and unplug the connection several times to clean the surfaces of both the plug and jack. Repeat a time or two to make certain all surfaces get cleaned.

With proper care, no harm should be done. If it doesn't remedy the situation, you're no worse off.

Works well with Mike jacks, RCA phono jacks, etc.

George