Oscilloscope for two red, black pens and respectively connected to the tube on both ends of the cathode GK no waveform testing, GK, BK, fairly RK are waveform. Then use the oscilloscope test Q314 base point A. This signal, so the judge fault from Q314 base and GK between a certain component. The first suspect Q314 damage. Welding Q314, under normal static measurement; Considering the RV302 carbon film potentiometer, heating may be spoiled or burn out for a long time. Welding under, the multimeter test found between its terminals is open circuit. After replacement, troubleshooting.Sx2service manual download site