Oscilloscope for two red, black table respectively access cathode GK test at both ends of the picture tube, no waveform at the GK, BK, RK has waves. Oscilloscope test Q314 again at the base of a point. This waveform, trouble comes from somewhere between the base and the GK Q314 components. First suspect Q314 damage. Welding Q314, static measurement, taking into account the RV302 carbon film potentiometer, prolonged cooking could spoil or burning out. Welding, use a multimeter tests found it at both ends has circuit breakers. After the replacement, troubleshooting.