Display shows dF or DF; refrigerator may not cool properly and may have frost buildup on the evaporator cover.

Safety first: Unplug the refrigerator before accessing the freezer back panel or any wiring. Use caution around sharp metal edges and melted ice water.

• Manually defrost: Remove freezer contents, unplug the unit, and leave the door open for 24 hours with towels to catch water. This will temporarily restore airflow and cooling.
• Access evaporator components: With power disconnected, remove the freezer back panel to expose the evaporator coil, defrost heater, and thermostat.
• Test defrost heater: Use a multimeter on the ohms setting across the heater terminals. A typical reading is 20–150 Ω. Infinite resistance indicates an open heater that must be replaced.
• Test defrost thermostat: While the thermostat is cold (covered in frost or placed in ice water), check continuity. It should show continuity when cold. If open when cold, replace it.
• Inspect wiring and connectors: Look for burnt, corroded, or loose connectors between the heater, thermostat, and control board.
• Replace failed parts: Install a new defrost heater or thermostat as needed, reassemble the panel, and restore power. If both test good, the main control board defrost circuit may be defective and require replacement.