Freezer shows E9; may run continuously or shut down unexpectedly, with abnormal temperature swings.

Safety first: Unplug the freezer before inspecting electrical components.

• Check outlet and cord: Verify the freezer is plugged directly into a grounded wall outlet (no extension cords). Inspect the power cord for cuts, burns, or kinks. Replace the cord if damaged.
• Verify supply voltage: If you have a multimeter and are qualified, measure the outlet voltage; it should be within the range specified on the freezer rating label (typically 220–240V or 110–120V depending on region).
• Inspect main PCB: Remove the rear control cover and look for burnt components, especially near the power input section (transformer, rectifier, capacitors).
• Reseat connectors: Ensure the power input connector and ground connections are tight and corrosion-free.
• Try a different outlet: Plug the freezer into a known-good outlet on a dedicated circuit to rule out household wiring issues.
• Replace PCB if needed: If the board shows visible damage or E9 persists despite stable power, replace the main control board with a Hisense-compatible unit.

Persistent power errors may indicate a household electrical problem; consult an electrician if multiple appliances are affected.