Re: her fault for being impatient?
"Not that there aren't still a lot of poor PSUs these days, particularly for consumer networking kit and similar."
A friend rang up to say their PC wouldn't power up. I was going through the usual checks - then the user suddenly went "oops!!". They had interpreted "switch it on" to include frustratedly flicking the on/off switch several times until there was a blue flash.
Stripping down the PC showed that the Enermax PSU had a vaporised fuse. Whatever had caused the problem was pretty drastic. Out of everything in the machine - only the fan had not been irrevocably killed.