Refrigerator not cooling in fresh food section but freezer is cold; ice buildup on back wall of freezer.

Safety first: Unplug the refrigerator and prepare towels for melting ice. Water and electricity are a dangerous combination.

Steps:

• Empty freezer: Remove food and shelves to access the rear panel.
• Inspect for frost: Remove the rear panel; if the evaporator coil is encased in solid ice, the defrost system is not working.
• Manual defrost: Use towels and a hair dryer on low or a bowl of hot water to melt ice. Do not use sharp tools or open flames.
• Test components:
  • Check the defrost heater for continuity with a multimeter.
  • Test the defrost thermostat for continuity when cold.
  • If both test good, suspect the main control board defrost circuit.
• Check drain: Ensure the defrost drain trough and tube are clear so meltwater can exit.

Corrective action: Replace any failed defrost components (heater, thermostat) and clear the drain. If those are good, replace the main control board. Reassemble and monitor for several days to confirm frost does not return.