High‑pitched whine or buzzing from the cooker during operation

Safety first: Unplug the cooker before opening the control housing.

• Confirm source: Listen carefully to locate whether the noise comes from the base (control board) or lid.
• Inspect control board: Remove the bottom cover and check that the board is firmly mounted. Tighten screws or add insulating washers if needed.
• Check for damage: Look for cracked or loose inductors/transformers. If any component is visibly damaged, replace the Cosori main control board.
• Monitor operation: If the noise is minor and the cooker operates normally, it may be harmless coil whine. If it worsens or is accompanied by errors, discontinue use and seek service.