Display shows Err or ERROR and the cooker will not operate.

Safety first: Unplug the cooker before any inspection. Do not repeatedly power-cycle if there is a burning smell or visible damage.

• Power reset: Unplug the unit for at least 15 minutes. Plug into a known-good outlet (avoid power strips) and try again.
• Check for other indicators: Note any additional icons or beeps that accompany the Err message; consult the user manual for model-specific meanings.
• Inspect for damage: Remove the bottom cover and visually inspect the main control board for burned components, bulging capacitors, or melted connectors.
• Check wiring harnesses: Ensure all sensor and heater connectors are firmly seated on the board. A disconnected sensor can sometimes trigger a generic error.
• Test basic functions: If Err clears after reset, run a simple warm or sauté cycle with water and monitor for recurrence.
• Replacement: Persistent Err messages with no obvious external cause usually indicate a failed main control board. Replacement should be performed by a qualified technician or through an authorized service center.