Teardown of the worst ATX power supply in the world

[DiTBho]

OVS, means "over voltage protection", right?

[Zoli]

OVS, means "over voltage protection", right?

Yes, "Over Voltage Protection"; quote marks stands for construction, since the feedback on those cheap PSU's are coming only to the 5V line. If you load only the other lines, the 5V lines goes up, and the feedback dials down the power.

[5U4GB]

Ohh those were the standard in the 2000s!

I can't remember all the details because it was 30 years ago but it brings to mind a mid-90s Compaq desktop power supply.  Among other things it used a cap dropper to power some sort of standby circuit that had a 1W resistor sitting at an unhealthy temperature 24/7 until either it burnt out or cooked the capacitor next to it. 

After that the circuitry got a bit hairy.

[5U4GB]

Never accept mains-powered gifts from PKTKS.

Timeo PKTKS et dona ferentes?

[hanakp]

OP reminded me of PSU I had in my Pentium 1 machine. I also had a gas boiler with an electromagnetic valve which controlled gas flow. When the electromagnet turned on, the PC hanged, every time, like a clockwork. It didn't reboot - screen turned black and PSU started to produce funny noises. I had to cycle power to fix it: insufficent electromagnetic compatibility in practice. It went away after I added a line filter to PC power inlet. It never happened with any other PC I had, even without the filter...