That power supply brick nearly took out my whole workbench

Last Tuesday I was testing a vintage receiver and the cheap replacement power supply I grabbed from a surplus bin started smoking after 10 minutes. I yanked it quick but it melted a spot on my mat and smelled like burning plastic for two days. Has anyone else had a mystery component just fail like that out of nowhere?

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1 Comment

patricia_lee1mo ago

That 240v side on those cheap bricks is usually where they cut corners. I pulled apart a dead one last month and the transformer winding had maybe three wraps of tape between the primary and secondary. One arc across that gap and your whole bench is seeing mains voltage. You probably got lucky it just smoked instead of dumping 120v into your receiver chassis. Those surplus bin deals are never worth the risk with power supplies.