Display shows E09; charger powers on but screen may flicker or reset; charging does not start.

Safety first: Turn OFF the breaker and wait several minutes for capacitors to discharge before opening the charger.

• 1. Observe behavior: With the cover on, restore power and watch the display. If it repeatedly reboots or dims, the internal low-voltage supply is unstable.
• 2. Internal inspection (qualified only): With power OFF, open the housing and locate the low-voltage power supply module (often a small board or enclosed module feeding 5V/12V to the main board). Check for burnt components, bulging capacitors, or discoloration.
• 3. Check connectors: Ensure all low-voltage harnesses between the power supply module, main control board, and display are firmly seated. Reseat any loose connectors.
• 4. Replace power supply module: If visible damage is present or output voltages are out of spec (requires meter and expertise), replace the low-voltage power supply module with the correct Besenergy part.
• 5. Main board damage: If the power supply tests good but E09 persists, the main control board may have internal shorts and should be replaced.

When to call a professional: Internal power supply diagnostics and replacement should be performed by a qualified technician.