I've got a ten-year-old ceiling fan in my bedroom. It was a cheapo to
begin with, not a name brand or anything, but it has worked, silently
and nicely, operating virtually 100% of the time, for the past ten years.
This morning, I stopped the thing for about 15 minutes to dust it,
something that had not been done for several months. When I turned it
back on - same speed as before - it was making kind of a scratchy,
mildly grating noise as it turned. It wasn't anything bad, like you'd
get if the bearings were shot. But it went from being 100% quiet to
being pretty scratchy sounding.
I sprayed some WD-40 on the moving parts with the fan stopped, restarted
it, and there was no improvement. I do remember reading somewhere once
that no attempt should ever be made to lubricate the fan.
I can't imagine that being turned off for 15 minutes, then on again,
would so badly degrade this fan's quietness. Any simple things that I
might have overlooked that would restore it to its previous glory?