Odd failure of desk fan

Internal fuse? Maybe a transformer? There are lots of way for things to go wrong. Open it up and have a look inside.

There has to be an overheat thermal fuse in the mortor winding for the situation of a kid pushing a pencil into the blades or whatever. Combined with the room temperature was probably the hottest this year and ordinary heat from the motor windings combined with a tired old thermal fuse, was the final straw

Was the body of the fan hotter than usual? If not then probably not winding overheating and thermal fuse. Fatigue fracture of the winding wire where it joins a terminal? Could you still turn the fan manually, or did one of the bearings sieze?

nib

I had the same experience yesterday.

Mine was a 16-inch floor standing fan which I've owned for about 5 years. This is it:

I left it running in the spare room and much to my surprise, when I checked it was no longer working. The various LEDs still light up in response to the remote control but the blades don't turn.

I suppose the motor burnt out but, like you, I am surprised as it wasn't used for more than about 500 hours in its entire life (equivalent to 20 full days).

AC fans like this typically have three speeds which are driven from two windings, A and B. Your options are to energise A, or B, or A+B. It's a little surprising to lose both windings together.

I'm guessing something in the common path is going to be the problem, either a fuse, a fried triac or something like that.

(improper heatsinking of power electronic devices is cheap electronics 101, unfortunately)

Theo

Nope

Not all faults make smoke or noise.