Toshiba tv makes static type sounds when I turn it...

Question

I have a Toshiba 19 inch portable tv . It works very well except for one thing. Every time I turn it on it make a loud noise like static and the pictures kind of jumps and this keeps up until I wiggle the cable at the back of the set. Then it will eventually stop until the next time I turn it on. Then it's the same thing. Do you think I need to solder in a new jack for the cable?
Thank you for your help.