The waveform below is commonly caused by a faulty PWM transformer TX4.
The waveform below is typical of an overdrive fault (2x1100 version only). This may be caused by a faulty IRF540 or in the
BC546-BC556-BF422 transistors in the FET drive section. Or it may be a result of breakdown in the BF422 transistors in the
driver stage (refer to
Tech Note #165
.)
