Sometime in the early evening, apparently while I was preparing dinner, the office fan died.
This is kinda important, given that the computers put out quite a lot of heat, as do I, so getting the air circulating is something of a priority in this weather.
Fortunately the lab fan (which has been flaky in the getting-started department, owing to sticky bearings, which I already cleaned & oiled once, and the fix didn't last) is currently working, and once started it keeps running, so I've moved that across the hall for now.
Examining the failed fan reveals that the bearings have gotten sticky... but it's beyond sticky bearings preventing it starting up; it failed while running, and attempting a manual-assist start with power applied gets no indication that the motor is even trying. So, assume a hard failure, and not worth my time, this busy week, to see if it's repairable.
Gotta swing by a store in the morning and buy a brand-new air mover. Phooey.