Unplug the fan before any repairs are made. Over time vibrations from a fan motor can loosen a plug from an older outlet so check this first.
Fan Repair
How to make a lasko fan stop rotating. Dust and dirt may cause your fan to make noise when running and can also clog up the fans internal mechanisms. Use canned air to dust any parts of the fan you cant reach. The oscillating feature also uses a motor attached to the main rotating blade motor. The motor begins rotating when the on switch activates causing the attached blades to spin as well. Stop oscillating the op means to stop the fan from moving side to side while blowing. Water and moisture should not enter either of the motors.
If the head of the fan doesnt move or makes noise when it moves it may have loose gears or worn gears on the clutch knob. Any moisture within the motors mechanical parts can corrode the internal bearings. If your plug keeps falling out you may want to replace the receptacle for a nice tight fit. Release the clamps on the fan grill or use a screwdriver to remove the grill. It sounds simple but your first step should be to make sure the cord is securely plugged in. 16 oscillating stand fan model 2521 great looking high performing and ideal for all rooms this black oscillating stand fan from lasko is fully featured.
User manual order parts features adjustable height tilt back fan head 3 quiet speeds. Fully adjustable height and tilt back head allow you to direct the airflow right where you need it most with 3 quiet speeds and widespread oscillation. Each fan uses a motor within the fans housing behind the spinning blades. Clean the blades and everything else you can reach with a soft damp cloth. Turn the fan on and set it stop. Corroded bearings will eventually seize causing fan turning failure for both the oscillating.
If you decide not to replace the gears or clutch knobs the only option is to keep the head stationary. Lock it may do the job.