Safety first: Unplug the dryer. The motor and control board operate at line voltage.

Step-by-step checks:

Check drum movement: Open the door and try to rotate the drum by hand. It should turn smoothly with moderate resistance. If it is very stiff or seized, the motor or drum support components may be binding.
Access the motor: Remove the front panel and drum (if necessary) to expose the drive motor. Note belt routing before removal.
Inspect wiring and connectors: Check the motor harness plug for secure fit, discoloration, or melted plastic. Reseat the connector and inspect the wiring back to the control board.
Test motor windings: With the motor disconnected, use a multimeter to measure resistance across the main and start windings (refer to Speed Queen service data if available). Infinite resistance or a dead short indicates a bad motor.
Control board relay: If the motor tests good and wiring is intact, the motor relay on the main control board may be defective. Look for burnt solder joints or relay damage. Replacement of the board is usually required.

When to call a technician: Motor replacement and control board diagnosis can be complex; if you lack tools or experience, contact a professional.

Dryer will not start, E03 displayed, sometimes accompanied by a humming sound from the motor area

Possible Causes