CONCERN: Customer reports Frigidaire refrigerator ice maker defrosting . Model LGUB2642LF9 CAUSE: Found back panel and evaporator coils covered in frost. Tested the refrigerator defrost bi-metal thermostat for continuity, refrigerator defrost bi-metal continuity failed test. Refrigerator defrost bi-metal has electrical short. CORRECTION: Defrosted refrigerator evaporator coils and replaced defrost bi-metal thermostat. Operation now normal.