Michael A. Terrell wrote:

Puddin' Man wrote:

(...)

Purchased ~ 4 years ago.
Used extensively mostly in summer of 2011 (maybe 10 hours/day).
Made strange sympathetic vibration sound, ~C#.

'Sounds like a failed bearing.

Worked OK about 3 weeks ago.
Stopped functioning altogether.

The shaft turns freely. No evidence of a heat problem.
Gets 120v thru feed wires.

As Michael mentioned, presenting 120 V to the coil does
not necessarily mean there is current through the coil.




No contacts on coil (cannot test voltage there).
Just sits there and looks dumb when powered.

Can't find -any- specs on it (Model MH-20UL)

Chinese wonder mystery, probably not worth further consideration?

'Probably true. Please use your multimeter to measure the resistance
of the switch when on, wires, connectors etc.

As Michael implies, your first - order test would be a resistance
measurement from prong to prong on the unplugged A.C. connector.

If it is 'open' and the switch and power cable tested OK, you're
probably not going to be able to repair the motor economically.
It is your call whether you want to unwrap the winding to discover
an open fuse as a matter of edification and entertainment,
before you throw it away.

If you are really economical (as I can be), you can salvage a low-
mileage shaded-pole motor out of a scrapped microwave oven and
use that in your fan. I see four in my scrap box from where
I'm sitting!

Shaft adapters are left as an exercise.

Do you have continuity through the winding? If not, then there is a
thermal fuse somewhere inside the motor. Usually, right under the point
where the wires enter the motor. If there are terminals, look and see
what size& type wire goes from them. If one is larger than the other,
that will be a lead from the fuse.


--Winston-- Salvage Safely! Some components can maintain sufficient
charge to knock you on your keester.