The bench supply went dark on Tuesday. No fan, no click from the relay, nothing on the front panel. The sensible thing, the thing every fibre of my time-poor self wanted, was to bin it and order a new one. It owes me nothing and they cost less than a decent meal out now.
I opened it anyway. Mostly because the screws were right there and the bin was not.
Lid off, and the fault was almost insultingly obvious: one electrolytic capacitor on the primary side with a domed top, the vent split, the faintest crust of dried electrolyte round the base. A 470uF, 25V part, the sort that lives a hard thermal life right next to the switching gear and gives up first. I had a pull from an old motherboard in roughly the right spec, swapped it in, reflowed two cold-looking joints whilst the iron was hot, and put it back together.
It powered up first try. Output rails are within a few millivolts of where they should be, which is better than I deserved.
The repair took twenty minutes and cost nothing. I am under no illusion this is economically rational against my hourly rate. But there is something genuinely satisfying about a fault you can see, point at, and fix, and you don't get that from a return label.