Hi all，
STTH110，the role of the diode in the two-tube forward circuit is the demagnetization of the transformer, which is found to burst in use.
The diode is exploded in the middle, pictured below:
The question is how did the diode break? The voltage and current waveform captured in normal operation does not exceed the requirements of the specification.
Can you help me see what's going on? thank you
