Did you by any chance spin the fan with the compressed air? As tempting as it is to do, you should avoid it cause doing so can turn the fan into an electric generator and send voltage to a place that is never meant to receive it.

Modern components should have protection against this, but sometimes companies cheap out. Regardless, even if you didn’t do this, I hope this comment helps at least one person.

This has happened to me, except with actual compressed air. I turned off, unplugged, and discharged the PC, just because I always do that before opening it up. I then popped off the panel and used my trusty compressed air can to dust it out. Put everything back in place, and nothing.

I’ve worked in tech long enough that I was actually shocked when the problem didn’t turn out to be something stupid I missed, like flipping the supply’s power switch. The damned PSU somehow killed itself on a previously-unused can of compressed air.