LG RCS511A Service Manual - Page 31

(TROUBLE 3) Display shows all figures set, but oven does not start cooking while desired program times are set and START pad is touched. CONDITION CONDITION 1. Setting time does not count down when touching START pad. CHECK Check continuity of secondary switch (with door closed). RESULT No continuity. Continuity. CAUSE Defective secondary switch. REMEDY Replace secondary switch. Check the connection between CN1 connector and PCB assembly. 2. Blower motor or oven lamp do not turn on. Check blower motor. Check oven lamp. Continuity No continuity Abnormal Abnormal Normal Defective PCB assembly. Loose connection. Replace PCB assembly. Connect them tightly. Defective blower motor. Defective oven lamp. Replace blower motor. Replace oven lamp. (TROUBLE 4) Oven seems to be operating but little heat is produced in oven load. CONDITION CHECK RESULT CAUSE REMEDY Output is low Check the power source voltage. Disconnect the wire leads from relay 3 and check on and off time with multitester. Lower than 90% of rating voltage. Normal Abnormal Normal Decrease in power source voltage with load. Defective PCB assembly. Suggest customer contact local electric power utility co. or qualified electrician. Replace PCB assembly. Measure the output power. Abnormal Defective magnetron. Replace magnetron. NOTE : Simple test of power output-conducted by heating one liter water for one min. if available. Minimum 8.5°C temperature rise is normal condition. 5-14