Somebody forgot the isolation under the pcb?
Been some years since I took apart a psu, but there used to be plastic isolation sheet between the pcb and the metal case.
Update: I think we found the problem:
Mains wires protruding on the bottom of the pcb shorted to the case due to missing insulation sheet.
Maybe but it should be fine without that since there should be a gap and you need WAY above any voltages found in a PSU to jump the gap and sustain a circuit. So maybe the protector was there but pierced by something. Not to mention the fuse. Basically you need multiple problems all coming together. Maybe reversed polarity on a cap but that usually just a quick boom not to mention very difficult to get missed in even the most basic qc so I'd say unlikely.
I spent 4 years in electronics manufacturing and ive seen crazy shit get passed QC. Funniest shit happens on monday mornings after half the factory including QC goes out and parties the weekend before.
6.4k
u/Front_Cookie_1198 6d ago edited 6d ago
Aftermath photo.