Diagnosis
Motor or belt strain. The burning smell is a critical sign of friction. The whine indicates a slipping drive belt or a obstructed motor fan.
How to Fix It
Immediately turn off and unplug the vacuum. Remove the nozzle plate and belt cover. Check the brush roll for obstructions (hair, string, carpet fibers). Remove them completely. Inspect the belt. If it is stretched, glazed, or cracked, replace it with part #0402D.
If That Didn't Work
The motor fan intake may be clogged with fine dust. This requires disassembly of the motor housing. Access is behind the dirt canister. Clear any debris blocking the fan blades.
Heads Up
A persistent burning smell after clearing obstructions means the motor insulation is damaged. Continued use is a fire hazard. Motor replacement is required.