Robot vacuum is very loud during operation, with a high-pitched whine or grinding noise.

Safety first: Power off and remove the robot from the charger. Avoid running the robot if you smell burning or see smoke.

Steps to diagnose:

• Isolate the noise: Run the robot upside down (carefully holding it) for a few seconds to determine if the noise comes from the brush area or the suction motor.
• Clean brush module: Remove the main brushes and clean them thoroughly. Run the robot briefly without brushes; if the noise disappears, the issue is in the brush system.
• Inspect brush gearbox (advanced): Remove the brush module (usually held by several screws) and open its cover to check for hair and debris in the gears. Clean and reassemble.
• Check vacuum intake: Inspect the suction inlet for foreign objects (e.g., small toys) and remove them.

When to replace parts: Persistent loud whine from the suction area indicates a failing vacuum motor. Grinding from the brush area suggests worn gears; replace the brush module.