Vacuum runs but a loud high‑pitched whine is heard and E11 or a fan icon appears; suction may be weak.

Safety first: Remove the battery before inspecting the motor area.

• Check for blockages: Ensure there is no restriction in airflow that could cause abnormal motor speed.
• Listen for bearing noise: Spin the motor (if accessible) by briefly powering on and off. Grinding or scraping sounds indicate bearing wear.
• Inspect connectors (advanced users): If you are comfortable and the warranty has expired, remove the outer housing screws to access the motor wiring harness. Check that connectors are fully seated. Do not disturb other components.

If E11 persists, the motor assembly (including tachometer) or control PCB is likely defective. Replacement of the complete motor unit is usually the most reliable repair and is best done by a professional.