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TECHNICAL FLASH
R
BASIC SERVICE MANUAL
FOR
MICROWAVE HOOD COMBINATION
MODEL 721. 64682/721. 64683
721. 64684/721. 64689
721. 80882/721. 80883
721. 80884/721. 80889
AUGUST, 2003

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Summary of Contents for Kenmore 721.80882

  • Page 1 TECHNICAL FLASH BASIC SERVICE MANUAL MICROWAVE HOOD COMBINATION MODEL 721. 64682/721. 64683 721. 64684/721. 64689 721. 80882/721. 80883 721. 80884/721. 80889 AUGUST, 2003...
  • Page 2 CAUTION WARNING TO SERVICE TECHNICIANS PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY a. Do not operate or allow the oven to be operated with the door open. b. Make the following safety checks on all ovens to be serviced before activating the magnetron or other microwave source, and make repairs as necessary;...
  • Page 3: Table Of Contents

    FOREWORD Read this Manual carefully. Failure to adhere to or observe the information in this Manual may result in exposing yourself to the Microwave Energy normally contained within the oven cavity. MODEL 721. 64682/721. 64683 721. 64684/721. 64689 721. 80882/721. 80883 721.
  • Page 4: Specifications

    SPECIFICATIONS Rated Power Consumption 1400W maximum (Microwave oven+Cook top lamps+Ventilation fan) Microwave Output 1200W (IEC 60705) Frequency 2,450 MHz ± 50 MHz Power Supply 120 VAC, 60 Hz Rated Current 12 Amp. (Microwave oven+Cook top lamps+Ventilation fan) Magnetron Cooling Forced Air Cooling Rectification Rectification Voltage Double Half-Wave Door Sealing...
  • Page 5: Cautions

    CAUTIONS Unlike other appliances, the microwave oven is MICROWAVE RADIATION high-voltage and high-current equipment. Personnel should not be exposed to the Though it is free from danger in ordinary use, microwave energy which may radiate from the extreme care should be taken during repair. magnetron or other microwave generating device if it is improperly used or connection.
  • Page 6: Installations

    INSTALLATIONS BEFORE YOU BEGIN, READ THE FOLLOWING INSTRUCTIONS COMPLETELY AND CAREFULLY. PRECAUTIONS ON INSTALLATION A. Plug the power supply cord into a 120V AC, 60Hz, single-phase power source with a capacity of at least 20 amperes. B. Avoid placing the unit in a location where there is direct heat or splashing water.
  • Page 7: Operating Instructions

    OPERATING INSTRUCTIONS CONTROL PANEL...
  • Page 8: Control Panel Instructions

    CONTROL PANEL INSTRUCTIONS 1. Display. The display includes a clock and indicators to 15. Start. Touch this pad to start a function. If you open the tell you time of day, cooking time settings, cook powers, door after the oven begins to cook, retouch Start. quantities, weights, and cooking functions selected.
  • Page 9: Overall Circuit Diagram

    OVERALL CIRCUIT DIAGRAM SCHEMATIC DIAGRAM...
  • Page 10: Matrix Circuit For Touch Key Board

    MATRIX CIRCUIT FOR TOUCH KEY BOARD EXPRESS SURE FROZEN HOLD ENTREE DEFROST SIMMER WARM VENT VENT DINNER SOFTEN MELT LIGHT ON/OFF 5 SPEED PLATE AUTO AUTO VEGETABLE POTATO PIZZA POPCORN REHEAT DEFROST MINUTE AUTO KITCHEN CLOCK MORE LESS COOK TIMER COOK STOP/ START...
  • Page 11: General Information For Service

    GENERAL INFORMATION FOR SERVICE FEATURES AND SPECIFICATIONS GENERAL PRECAUTIONS IN USE FEATURES A. Never operate the unit when it is empty. Operating the oven with no load may shorten the A. The safety systems incorporated in this model are: life of the magnetron. Whenever cooking dry foods (1) Primary interlock switch (dried fish, bread, etc.) or a small amount of food, (2) Secondary interlock switch...
  • Page 12: Service Information

    SERVICE INFORMATION PRECAUTIONS AND REPAIR SERVICE TIPS PRELIMINARY (3) Do not operate the unit until it is completely A. SINCE NEARLY 4000 VOLTS EXISTS IN SOME repaired, if any of the following conditions exist. CIRCUITS OF THIS UNIT REPAIRS SHOULD BE The unit must not be operated.
  • Page 13: Microwave Leakage Test

    MICROWAVE LEAKAGE TEST EQUIPMENT CAUTIONS • TESTER (VOLTS-DC, AC, Ohmmeter) • Be sure to check microwave leakage prior to servicing the oven if the oven is operative prior to • Microwave survey meter servicing. - Holaday HI-1500 • The service personnel should inform the HI-1501 manufacture importer, or assembler of any certified - Narda...
  • Page 14: Power Output Measurement

    MEASUREMENT WITH THE OUTER CASE NOTE WHEN MEASURING REMOVED (1) Do not exceed meter full scale deflection. (2) The test probe must be removed no faster than (1) When you replace the magnetron, measure for 1 inch/sec (2.5cm/sec) along the shaded area, microwave energy leakage before the outer case otherwise a false reading may result.
  • Page 15: Disassembly Instructions

    DISASSEMBLY INSTRUCTIONS IMPORTANT NOTES: (4) Remove 3 screws securing the circuit board. UNIT MUST BE DISCONNECTED FROM ELEC- TRICAL OUTLET WHEN MAKING REPAIRS, RE- PLACEMENTS, ADJUSTMENTS AND CONTIN- Circuit Board UITY CHECKS. WHEN RECONNECTING THE WIRE LEADS TO ANY PART, MAKE SURE THE WIRING CONNE- CTIONS AND LEAD COLORS ARE CORRECTLY MATCHED ACCORDING TO THE OVERALL CIR- CUIT DIAGRAM.
  • Page 16 HOW TO INSERT THE F.P.C. CONNECTOR HOW TO REMOVE THE F.P.C. CONNECTOR Follow the steps below as illustrated in Figures 6 Follow the steps below as illustrated in Figures 4 and 7 to insert the F.P.C. connector. and 5 to remove the F.P.C. connector. (1) Insert the F.P.C.
  • Page 17 B. REMOVING THE OUT CASE(Figure 8) (1) Remove the vent grille by removing two screws securing it to the out case. (2) Remove two screws securing it to the air duct. (3) Remove the mounting plate by turning the screws (1 or 2 screws) securing it to the out case.
  • Page 18 C REMOVING THE DOOR INTERLOCK SWITCHES (Figures 9,10) (1) Disconnect the wire leads from the interlock switches. (2) Remove two screws securing the Latch Board. (3) Make necessary replacements and check microwave energy leakage according to Latch Board “ADJUSTMENT PROCEDURES” on page 7-12. Primary Interlock Switch Latch Board...
  • Page 19 D. REMOVING MAGNETRON E. REMOVING THE INVERTER MODULE (Figures 11 Through 12) (Figures 13 Through 15) (1) Remove the vent grille by loosening two screws. (1) Remove the vent grille by loosening two screws. (Figure 11) (Figure 11) (2) Remove the outcase. See page 7-6. (2) Remove the outcase.
  • Page 20 F. REMOVING STIRRER FAN G. REMOVING DOOR (Figure 18) (Figures 16 and 17) (1) Remove the vent grille by two screws securing it to (1) Remove one rivet ASS'Y securing it to the oven the outcase loosening. upper plate by using knife blade. (2) Lift up and draw the door.
  • Page 21 I. ASSEMBLING DOOR (3) Carefully pull the ventilation motor ASS'Y out of (1) When mounting the door assembly to the oven the microwave oven. (See Figure 21-b) assembly, be sure to adjust the door assembly parallel to the chassis. Also adjust so the door has no play between the inner door surface and oven frame assembly.
  • Page 22 K. REMOVING THE TURNTABLE MOTOR (1) Remove the glass tray and rotating ring. (2) Remove the turntable shaft VERY CAREFULLY with a hand. (Figure 22) (3) Remove the base plate by removing 8 screws securing it to the oven cavity. (Figure 23) (4) Disconnect the leadwire from the turntable motor terminals.
  • Page 23: Interlock System

    INTERLOCK SYSTEM INTERLOCK MECHANISM The door lock mechanism is a device which has been specially designed to eliminate completely microwave activity when the door is opened during cooking and thus to prevent the danger resulting from the microwave leakage. CHECK THE DOOR LATCH AND SWITCH ADJUSTMENT PROCEDURES CLOSING.
  • Page 24 TEST THE LATCH AND SWITCH SEQUENCE (5) Open the oven door slowly. Watch the door latch, (7) When you achieve the proper sequence of the Secondary Switch. Release Rod and Lever switches in Steps 5 and 6, tighten the latch board on the switches to make sure they are zero to the screws at that point.
  • Page 25: Interlock Continuity Test

    INTERLOCK CONTINUITY TEST A. PRIMARY INTERLOCK SWITCH TEST B. SECONDARY INTERLOCK SWITCH TEST Disconnect the wire lead from the secondary When the door is opened slowly, an audible click switch. should be heard at the same time or successively Connect the ohmmeter leads to the common at intervals and the latches should activate the (COM) and normally open (NO) terminals of the switches with an audible click.
  • Page 26: Test And Checkout Procedures And Troubleshooting

    TEST AND CHECKOUT PRECEDURES AND TROUBLESHOOTING CAUTIONS 1. DISCONNECT THE POWER SUPPLY CORD FROM THE OUTLET WHENEVER REMOVING THE OUTER CASE FROM THE UNIT. PROCEED WITH THE TEST ONLY AFTER DISCHARGING THE HIGH VOLTAGE CAPACITOR AND REMOVING THE LEAD WIRES FROM THE INVERTER MODULE. 2.
  • Page 27 COMPONENTS TEST PROCEDURE RESULTS Antenna Gasket Chassis Filament NOTE: When testing the magnetron, be sure to install the magnetron gasket in the correct position and be sure that the gasket is in good condition. SENSOR Normal: Approximately 1. Disconnect sensor connector from micom BK-RD: 5.6 Kohms computer board.
  • Page 28 COMPONENTS TEST PROCEDURE RESULTS Measure the resistance. FAN MOTOR Normal: Approx. 50 ~ 150 ohms (Wire leads removed) (Ohm-meter scale: R x 100) Abnormal: Infinite or several B(BK) ohms. A(RD) C(WH) A-B: 76 ohms B-C: 22 ohms A-C: 96 ohms Measure the resistance.
  • Page 29 KEY MATRIX COMPONENTS TEST PROCEDURES RESULTS Measure the resistance between terminal When When not pins of connector KEY CONNECTOR. Resistance touched touched NOTE: value Less than More than When reconnecting the FPC connector, 400 ohms 1 mega ohm make sure that the holes on the FPC connector are properly engaged with hooks on the plastic fastener.
  • Page 30: Checkout Procedures

    NOTES: • A MICROWAVE ENERGY TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS SERVICED FOR ANY REASON. • MAKE SURE THE WIRE LEADS ARE IN THE CORRECT POSITION. • WHEN REMOVING THE WIRE LEADS FROM THE PARTS, BE SURE TO GRASP THE CONNECTOR, NOT THE WIRES.
  • Page 31 (2) CHECKOUT PROCEDURES FOR RELAY. - PROBLEM (A) - - PROBLEM (A) - FAN motor turns on without touching START key Oven lamp turns on without touching START key when the door is closed. when the door is closed. Remove the mate connector of I/O Remove the mate connector of I/O GOOD GOOD...
  • Page 32 (3) CHECKOUT PROCEDURES FOR CIRCUIT BOARD The following symptoms indicate a defective circuit 5) Some segments of one or more digits do not light board. up, or they continue to light up, or segments light 1) Check the input current. If the input current is more when they should not.
  • Page 33: Troubleshooting

    C. TROUBLE SHOOTING WHEN YOU GET A COMPLAINT FROM YOUR CUSTOMER, EVALUATE THE COMPLAINT CAREFULLY. IF THE FOLLOWING SYMPTOMS APPLY, PLEASE INSTRUCT THE CUSTOMER IN THE PROPER USE OF THE MICROWAVE OVEN. THIS CAN ELIMINATE AN UNNECESSARY SERVICE CALL. CAUTIONS 1.
  • Page 34 (TROUBLE 1) The following visual conditions indicate a probable defective control circuit. 1. Incomplete segments. • Segment missing. • Partial segment missing. • Digit flickering (NOTE: Slight flickering is normal.) 2. Colon does not turn on or blink. 3. A distinct change in the brightness of one or more numbers in display. 4.
  • Page 35 (TROUBLE 2) Oven does not operate at all, Display window does not display any figures, and no input is accepted. CONDITION CHECK RESULT CAUSE REMEDY Malfunction of the Check continuity 1. Fuse blows. Continuity. Replace fuse, monitor switch. of monitor primary, monitor switch (with switches, and...
  • Page 36 (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 CHECK RESULT CAUSE REMEDY Defective Replace Check continuity 1. Setting time No continuity. secondary switch. secondary switch.
  • Page 37 CONDITION CHECK RESULT CAUSE REMEDY Connect them Check the Abnormal Loose connection. 4. The display tightly. connection between shows F-4. sensor wire and control PCB. Normal Check the sensor. Abnormal Defective sensor. Replace sensor. Defective Control Replace PCB Normal PCB assembly. assembly.
  • Page 38: Exploded View

    #EV# EXPLODED VIEW DOOR PARTS MODEL: 721. 64682/721. 64683 721. 64684/721. 64689 721. 80882/721. 80883 721. 80884/721. 80889 1005 1002 1004 1000 FOR 64683 ONLY 80883 1381 W171 1008 1003 1007 1006 1011 W109 1009...
  • Page 39 #EV# CONTROLLER PARTS For Model: 2004 721.64682 W106 721.64684 2381 721.64689 2002 721.80882 721.80884 721.80889 2000 2006 2008 W136 2009 2007 For Model: 2004 721.64683 W106 721.80883 2381 2006 2008 W136 2009 2007...
  • Page 40 #EV# OVEN CAVITY PARTS FOR 64682/64684 FOR 64682/64684 W108 3010 W138 W138 80882/80884 80882/80884 FOR 64689/64683 FOR 64689/64683 W142 W142 80889/80883 80889/80883 3031 W138 W142 W109 3024 3029 3001 W121 3003 3043 3036 3005 3033 W150 3018 W121 5036 6000 3032 3026 5382...
  • Page 41 #EV# LATCH BOARD PARTS 4000 4002 W102 4001 4003 4002 4004...
  • Page 42 #EV# INTERIOR PARTS (I) W130 5049 5025 5026 W146 3002 W109 W109 3008 5012 W109 W101 5003 3017 5057 W109 5052 W109 5009 W101 5024 5000 3007 W109 3009 5066 W109 W105 3054 5048 3382 W109 5035 5044 3004...
  • Page 43 #EV# INTERIOR PARTS (II) W150 3027 W150 W144 W109 5027 5016 5011 5019 5001 5041 5045 W144 5010 5006 5015 5038 5014 5029 5037...
  • Page 44 #EV# INSTALLATION PARTS 6011 6008 6010 6009...
  • Page 45 P/NO : 3828W5S3334 Printed in Korea...

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