Hi, it looks like there is a poor connection( dry joint) in the field output circuitry, either on the i.c. or scan coil plug/socket as physically disturbing the chassis corrects the fault. If the picture is o.k. ( white content of pic doesnt go silvery when you turn up the brightness) it might be worth a repair although the crt could be coming to the end of its life after 14 yrs ,just depends how much use it gets.if its your main set and not a portable it would be worth it,as no parts are required just a soldered connection repair.
howard
July 2008