Post #2370592

Remember this thread? https://cathode.church/@s0/114959788512020266 Well today I dissected another cheap USB PSU, this time a simple “10W” 5V one with a single USB-A outlet. And folks, this one was a shocker. Literally. ✅ start with the good — pin sheathing on correctly sized pins, and it fits nicely in a standard Australian outlet footprint. 🚨 downhill from here — the case is flimsy, thin, and poorly glued. It would easily break open from a fall or knock. 🚨 The PCB underside makes a go at an isolation barrier between mains and low voltage side, up until it just… doesn’t. Next to the USB chassis, solder joints are <2mm apart. The primary side bulk capacitor is pressed hard against the USB receptacle, with only its wrapper to isolate. Any flaw or damage to this cap and your laptop chassis will be at 330V DC! 🚨 The wires from the pins to the board have thin, uneven PVC insulation. Worse, one was trapped during assembly, damaging that insulation and the copper inside. 🚨 The fuse is low quality fusible resistor type, unprotected, and jammed against the case. Prolonged use at the edge of the current rating could melt the case and start a fire easily. I haven’t tested if the case is fire retardant, but I’m not holding my breath. I hope to test the chassis leakage current tomorrow, but I know it’ll be bad.