To avoid serious injury follow all warnings and instructions in the manual. Wear appropriate personal protective equipment.
Check cord to make sure fan has power.
Clear debris from fan/fan grill.
Try to stop fan by lightly pressing on the center with a pencil eraser. If the fan slows down easily it will need to be replaced.
Move machine to an area below 120°F.
Reset coupler per specifications and retighten set screws.