KV27TS30 Sony TV Problem (HV PS ?)

Your set isthe LN-1 chassis that problem is definately in the deflection / high voltage circuitry most likely the flyback itself. however this chassis has a history of bad solder cracks around the flyback and horizontal transformer mounting locations. I would check the solder before replacing the flyback. Also notethat if this condition has been ongoing without putting the set into protective shutdown you will also be looking at possibly having some weak regulator transistors and leaky diodes on the power supply module. Let me know if you need further info or a service manual for this set.