Philips tv has shrinking picture

I have a 20" Philips model# 20pt6441 that the top of the picture is shrinking down, everything else is ok. I'm looking for someone that can tell me just how to fix it. Thanks. Sam

Possibly the vertical output IC chip. I'd inspect the solder pads on the underside of the circuit board first. These chips heat up and often loosen the solder connections. It can also be a faulty support component connected to the vertical out chip.

try resoldering the frame ic-check by replacement the scan coupling capacitor and the flyback boost capacitor....you may also have a faulty frame ic..........