Sharp R-230HW Service Manual - Page 12

R-203HW R-220HW R-230HW TEST PROCEDURE CK = Check / RE = Replace RE CK A B C D E F F G H RE RE CK I/K CK CK CK J M L POSSIBLE CAUSE AND DEFECTIVE PARTS SHORT IN POWER CORD SHORT OR OPEN WIRING MAGNETRON POWER TRANSFORMER H.V. RECTIFIER ASSEMBLY HIGH VOLTAGE CAPACITOR TEMPERATURE FUSE (OVEN) PRIMARY INTERLOCK SYSTEM SECONDARY INTERLOCK SWITCH MONITOR SWITCH C/T FUSE OVEN LAMP OR SOCKET COOLING FAN MOTOR TURNTABLE MOTOR CONTROL UNIT OR RELAY WRONG OPERATION LOW VOLTAGE DIRTY OVEN CAVITY KEY UNIT FOIL PATTERN ON PWB. DEFROST CONDITION OFF CONDITION COOKING CONDITION PROBLEM Home fuse blows when power cord is plugged into wall receptacle. C/T fuse blows when power cord is plugged into wall receptacle. Any letters or indicators do not appear in display when power cord is first plugged into wall outlet. Display does not operate properly when STOP/CLEAR key is touched. (Buzzer should sound and time of day should appear in display.) C/T fuse blows when the door is opened. Fan motor does not operate. (All other electric components function.) Oven lamp does not light at all. (All other electric components function.) Turntable motor does not operate. (All other electric components function.) Oven does not go into cook cycle when START pad is touched Oven seems to be operating but little or no heat is produced in oven load. (Food incompletely cooked or not cooked at all at end of cook cycle.) Oven goes into a cook cycle but extremely uneven heating is produced in oven load (food). Oven does not cook properly when programmed for Cooking 50% mode. (Operates properly on Cooking Power 100% mode.) Oven lamp, turntable motor and fan motor do not operate. Oven goes into DEFROST but food is not defrosted well. TEST PROCEDURES PROCEDURE LETTER A MAGNETRON ASSEMBLY TEST COMPONENT TEST 1. Disconnect the power supply cord, and then remove outer case. 2. Open the door and block it open. 3. Discharge high voltage capacitor. 4. To test for an open filament, isolate the magnetron from the high voltage circuit. A continuity check across the magnetron filament leads should indicate less than 1 ohm. 10