E9 error appears and the cooker will not start; sometimes accompanied by beeping.

Safety first: Unplug the cooker before any inspection.

External checks:

• Test the outlet with another appliance to confirm proper voltage.
• Inspect the power cord and plug for damage. Replace if any cuts or burns are visible.

Internal checks (advanced):

• Remove the bottom cover and locate the AC input terminals and the low-voltage power supply section on the PCB.
• Check for loose screws or connectors at the AC input.
• Look for bulging or leaking electrolytic capacitors in the power supply area.

Because power supply faults can be hazardous, board-level repair should be left to professionals. Most users should replace the entire control board or contact T-fal service.