Attached is the circuit I am using to power my SMPS, at random power-up D5 fails (short circuit).
I noticed that the first time when the circuit is connected to a variac (PFC not operating) it was working fine, I tried to change the AC-INPUT voltage going from 100VAC to 240VAC then it stopeed working while I was playing with the voltage.
Today, at 175VAC I powered it up then the same story, D5 shorts out.
Any idea on why I am facing this issue? is it because of the diode type?
I am using 600uH inductor not 1MH because noise is LESS at that value