E9 appears and the unit shuts down or will not start; sometimes accompanied by a burning smell previously.

Safety: Disconnect the appliance from mains power before opening the electronics compartment.

Steps:

• Power reset: Unplug the unit for at least 15 minutes to allow capacitors to discharge and the control to fully reset. Plug back in and check if E9 persists.
• Check power source: Verify that the outlet provides stable voltage within the range specified on the Argo rating label. Avoid using undersized extension cords.
• Inspect main PCB: Remove the control cover and visually inspect the main PCB for burnt components, cracked solder joints, or moisture damage.
• Dry moisture: If there are signs of condensation, allow the board to dry completely in a warm, dry environment before retesting.
• Replace main PCB: If E9 remains and there is no obvious external cause, replace the Argo main control PCB (with EEPROM). Transfer any model-specific jumpers or settings as per service documentation.
• Surge protection: After replacement, consider using a surge-protected outlet to prevent future EEPROM corruption.