Freezer display shows AL05; unit may not defrost properly, leading to ice buildup and poor cooling.

Safety first: Unplug the freezer before removing interior panels or working near the evaporator and heater. Beware of sharp fins and edges.

• Inspect for heavy frost: Remove baskets and the rear interior panel. If the evaporator is encased in solid ice, the defrost system is likely not working.
• Check defrost sensor: Locate the defrost sensor (often attached to the evaporator tubing). Inspect for cracks or corrosion. If you have a multimeter, test for appropriate resistance at room temperature; an open or shorted sensor must be replaced.
• Check defrost heater (if accessible): The heater is usually a metal or glass tube at the base or woven through the evaporator. Disconnect its connectors and test for continuity. An open circuit indicates a failed heater.
• Manual defrost: To restore temporary operation, fully defrost the evaporator by leaving the unit unplugged with doors open until all ice melts. Do not use sharp tools to chip ice.
• Replace failed components: Install a new defrost sensor or heater as needed, routing wires away from hot surfaces and moving parts. Reassemble panels and restore power.

If AL05 returns quickly after component replacement, the main control board defrost relay or logic may be faulty and should be checked by a technician.