Top section of the picture gets reversed and...

Question

Intermittently the picture in the top 6-8" of the screen compresses into multiple smaller horizontal sections of different sizes and with portions appearing to be upside down. The bottom portion of the screen is unaffected. I tried swapping the coaxial cable but the problem continued. If I wiggle the coaxial cable input it sometimes helps but I've tested the TV with just an s-video input and also with no inputs and the same thing happens. I have run all the components through another tv (15") and did not see the issue occur in the other tv.Initially there was a thin white line running horizontally across the screen with the upper section becoming slightly blurry. If I tapped the tv the line would often disapper. Does anyone know what may be the causing the problem and if so whether its worth trying to have it fixed?Thank you for any assistance or input.Simon