CONCERN: Customer reports Samsung refrigerator is not getting cold on refrigerator side. Model RF20HFENBSR DIAGNOSTIC AND CAUSE: Inspected compressor operation, evaporator fan and condenser fan operation, all normal. Found frost build up on evaporator coils. Tested defrost heater for continuity, Found defrost heater and limiter shorted. CORRECTION: Replaced defrost heater and limiter. Tested operation, all normal upon completion.