Sears 721.80042 Basic Field Manual
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Sears 721.80042 Basic Field Manual

Sears 721.80042 Basic Field Manual

Microwave oven
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DIVISION 22
BASIC FIELD MANUAL

MICROWAVE OVEN

MODEL 721.80042700
June, 2007
FOR
721.80049700
721.80044700
721.80043700
721.81043700
MODEL 721.80042
721.80049
721.80044
721.80043
721.81043

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  • Page 1: Microwave Oven

    MODEL 721.80042 721.80049 721.80044 721.80043 721.81043 DIVISION 22 BASIC FIELD MANUAL MICROWAVE OVEN MODEL 721.80042700 721.80049700 721.80044700 721.80043700 721.81043700 June, 2007...

  • Page 2: Safety Precautions

    CAUTION SAFETY PRECAUTIONS 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. TABLE OF CONTENTS (Page) SAFETY PRECAUTIONS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Inside front page SPECIFICATIONS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1-1 CAUTIONS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 2-1 INSTALLATIONS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 3-1...

  • Page 4: Specifications

    SPECIFICATIONS Rated Power Consumption - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1500W maximum (Microwave oven+Cook top lamps+Ventilation fan) Microwave Output - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1000W (IEC60705) Adjustable 100W through 1000W, 10 steps Frequency - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 2450 MHz ±...

  • 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 15A or 20A. 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 14. Soften. Touch this pad to soften utter,ice indicators to tell you time of day, cooking time cream, cream cheese, or frozen juice. settings, cook powers, quantities, weights and 15.

  • Page 9: Overall Circuit Diagram

    OVERALL CIRCUIT DIAGRAM SCHEMATIC DIAGRAM...

  • Page 10: Matrix Circuit For Touch Key Board

    MATRIX CIRCUIT FOR TOUCH KEY BOARD...

  • Page 11: General Information For Service

    GENERAL INFORMATION FOR SERVICE GENERAL PRECAUTIONS IN USE FEATURES AND SPECIFICATIONS 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 2,100 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 CAUTIONS MEASURING MICROWAVE ENERGY LEAKAGE • Be sure to check microwave leakage prior to servicing the oven if the oven is operative prior to • Pour 275±15cc of 20±5°C(68±9°F) water in a beaker servicing. which is graduated to 600 cc, and place the beaker •...

  • Page 14: Measurement With The Outer Case Removed

    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- UITY CHECKS. WAIT AT LEAST ONE MINUTE, UNTIL THE HIGH VOLTAGE CAPACITOR IN THE HIGH VOLTAGE POWER SUPPLY HAS FULLY DISCHARGED.
  • Page 16 HOW TO REMOVE THE F.P.C. CONNECTOR HOW TO INSERT THE F.P.C. CONNECTOR Follow the steps below as illustrated in Figures 4 Follow the steps below as illustrated in Figures 6 and 5 to remove the F.P.C. connector. and 7 to insert the F.P.C. connector. (1) Hold the edges of the plastic fastener with (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 front bracket. (3) Remove two screws securing it to the air duct. (4) Remove the mounting plate by turning the two 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 PROCEDURE” on page 7-12. Secondary Interlock Switch Interlock...
  • Page 19 D. REMOVING MAGNETRON NOTES: • When removing the magnetron, make sure that its (Figures 11 Through 13) dome does not hit any adjacent parts, or it may be (1) Remove the vent grille. damaged. (2) Remove mount, all. (3) Remove outcase. •...
  • Page 20 E. DOOR ASSEMBLY / REMOVAL 1) Open the door. 2) Remove the choke cover very carefully with a flat- blade screwdriver. CAUTION : Be careful not to damage door seal plate by screwdriver. 3) Lift up and push the door. Remove door assembly Remove door assembly...
  • Page 21 F. ASSEMBLING DOOR (3) Carefully pull the ventilation motor ASS'Y out of the microwave oven. (See Figure 18) (1) When mounting the door assembly to the oven 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 H. REMOVING THE TURNTABLE MOTOR (1) Remove the turntable. (2) Remove the turntable shaft VERY CAREFULLY with a slotted screwdriver. (Figure 19) (3) Remove the base plate by removing eight screws securing it to the oven cavity. (Figure 20) (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. ADJUSTMENT PROCEDURES CHECK THE DOOR LATCH AND SWITCH To avoid possible exposure to microwave energy 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 When the door is opened slowly, an audible click Disconnect the wire lead from the secondary should be heard at the same time or successively switch. at intervals and the latches should activate the Connect the ohmmeter leads to the common switches with an audible click.

  • Page 26: Test And Checkout Procedures And Trouble Shooting

    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 PRIMARY WINDING OF THE HIGH VOLTAGE TRANSFORMER. 2.
  • Page 27 COMPONENTS TEST RESULTS 1. Check DC 9V battery before performing tests. H.V.Capacitor 2. Select the DCV scale on the meter. 3. Using the meter, battery, and jump wire, connect the items as illustrated in figures. • Terminal to terminal Normal: Approximately 9V Abnormal : Approximately 0V...
  • Page 28 COMPONENTS TEST RESULTS Measure the resistance between terminal TOUCH KEY BOARD When When not pins of connector KEY CONNECTOR. touched touched NOTE: Resistance When reconnecting the FPC connector, value More than Less than make sure that the holes on the FPC 1 mega ohm 400 ohms connector are properly engaged with hooks...
  • Page 29 COMPONENTS TEST RESULTS 1. Measure continuity. Power Relay 8 Open Close (ohm meter scale: Rx1) Level 2. Remove the lead wires and operate 18 Sec 4 Sec oven at power level 1 through power level 10. 6 Sec 16 Sec 14 Sec 8 Sec 12 Sec...

  • Page 30: Checkout Procedures

    B. CHECKOUT PROCEDURES (1) CHECKOUT PROCEDURES FOR FUSE BLOWING CAUTION: REPLACE BLOWN FUSE WITH 20 AMPERE FUSE. PROBLEMS CAUSES Fuse blows immediately after the door is closed. Improper operation of the primary interlock, secondary Fuse blows immediately after interlock switches and/or the interlock monitor switch. the door is opened.
  • Page 31 (2) CHECKOUT PROCEDURES FOR RELAY. - PROBLEM (A) - Oven lamp turn on without touching START key when the door is closed. Remove the mate connector of I/O GOOD CON from the circuit board. Does the unit still operate? Replace the Defective circuit board RELAY1...
  • Page 32 (3) CHECKOUT PROCEDURES FOR CIRCUIT BOARD The following symptoms indicate a defective circuit 6) Wrong figures appear. board. 7) The figures of all digits. 1) The start function fails to operate but the high 8) Some of the indicators do no flicker light up. voltage Systems, the interlock switches, the door 9) The clock does not keep time properly.
  • Page 33 7-22...
  • Page 34 7-23...
  • Page 35 7-24...
  • Page 36 7-25...

  • Page 37: Exploded View

    #EV# EXPLODED VIEW DOOR PARTS For Model : 721.80049700 721.80042700 1004 721.80044700 1005 1002 1000 1008 W109 1003 1006 W109 1007 1009 For Model : 721.80043700 721.81043700 1004 1005 1002 1000 1008 W109 1381 1006 W109 1007 1009 -8-1-...

  • Page 38: Controller Parts

    #EV# CONTROLLER PARTS For Model : 721.80049700 721.80042700 2004 721.80044700 2006 2381 W106 2008 2018 W101 2000 2002 For Model : 721.80043700 721.81043700 2004 2381 2006 W106 2008 2018 W101 -8-2-...

  • Page 39: Oven Cavity Parts

    #EV# OVEN CAVITY PARTS W108 3010 W109 For Model W142 721.80049 721.8 0043 721.81043 For Model W138 721.80042 721.80044 3024 W142 3029 W138 3001 3003 W105 5038 5036 6001 6000 3028 3011 3026 3025 W118 W118 3026 -8-3-...

  • Page 40: Latch Board Parts

    #EV# LATCH BOARD PARTS 4000 4001 4002 W102 4003 4002 4004 -8-4-...
  • Page 41 #EV# INTERIOR PARTS (I) W101 3002 5039 5009 3012 W101 W109 3008 W109 W108 5008 3034 5035 3037 3009 W101 W109 W101 W105 5018 W108 5002 5000 5034 -8-5-...
  • Page 42 #EV# INTERIOR PARTS (II) 3027 5015 5037 5045 5038 W108 W109 5010 5337 5006 W136 5001 5041 5004 5016 5011 W101 5014 5024 5058 5043 5044 3004 -8-6-...
  • Page 43 #EV# INSTALLATION PARTS 6008 6011 6010 6009 VINYL COOKING *06-1 *06-2 UPPER WALL OWNERS INSTALLATION GUIDE TEMPLATE TEMPLATE MANUAL MANUAL LABEL -8-7-...

This manual is also suitable for:

721.80044721.80043721.80049721.81043

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