Sears 721.69252990 Basic Field Manual
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Sears 721.69252990 Basic Field Manual

Sears 721.69252990 Basic Field Manual

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MODEL 721.69252990
721.69259990
DIVISION 20
BASIC FIELD MANUAL
FOR

MICROWAVE OVEN

MODEL 721.69252990
721.69259990
June, 1999

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  • Page 1: Microwave Oven

    MODEL 721.69252990 721.69259990 DIVISION 20 BASIC FIELD MANUAL MICROWAVE OVEN MODEL 721.69252990 721.69259990 June, 1999...

  • Page 2: Warning To Service Technicians

    MODEL 721.69252990 721.69259990 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

    MODEL 721.69252990 721.69259990 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 721.69252990 721.69259990 MECHANICAL SERVICE INFORMATION TABLE OF CONTENTS 1.

  • Page 4: Adjustment Procedures

    MODEL 721.69252990 721.69259990 1. ADJUSTMENT PROCEDURES ADJUST THE LATCH AND SWITCH CLOSINGS To avoid possible exposure to microwave energy (3) Loosen the two screws holding the plastic latch board leakage, adjust the door latches and interlock as shown. switches, using the following procedure.
  • Page 5 MODEL 721.69252990 721.69259990 LATCH BOARD SCREW SECONDARY INTERLOCK DOOR LATCH SWITCH INTERLOCK MONITOR SWITCH RELEASE LEVER PRIMARY INTERLOCK SWITCH SCREW Figure 1-a LATCH 0-1/64" LATCH BOARD 0-1/64" Figure 1-b...

  • Page 6: Precautions On Installation

    MODEL 721.69252990 721.69259990 2. PRECAUTIONS ON INSTALLATION (Figure 2) B. Touch the STOP/CLEAR and the COOK TIME keys. A. Plug the power supply cord into a 120 V AC, C. Set cooking time for 10 minutes by touching “1” 60 Hz, single-phase power source with a capacity of and then “0”...

  • Page 7: Specifications

    MODEL 721.69252990 721.69259990 SPECIFICATIONS Rated Power Consumption 1530W maximum Output 1100W maximum (*IEC 705 Rating standard) Adjustable 100W through 1100W, 11 steps Frequency 2,450 MHz 50 MHz Power Supply 120V 12V AC, 60Hz Rated Current 13.3 Amp. Magnetron Cooling Forced Air Cooling...

  • Page 8: Overall Circuit Diagram

    MODEL 721.69252990 721.69259990 6. OVERALL CIRCUIT DIAGRAM A. SCHEMATIC DIAGRAM MGT/OVEN AC 120V/60Hz THERMOSTAT SINGLE PHASE ONLY FUSE L.V. TRANSFORMER PRIMARY INTERLOCK SWITCH (NO) OVEN LAMP RELAY 1 MOTOR (CN1) SECONDARY INTERLOCK RELAY 2 SWITCH TURNTABLE MOTOR MONITOR SWITCH (NC) H.V.TRANSFORMER...
  • Page 9 MODEL 721.69252990 721.69259990 B. MATRIX CIRCUIT FOR TOUCH KEY BOARD SENSOR SENSOR AUTO USER KITCHEN CLOCK POPCORN COOK TIMER DEFROST CHOICE QUICK QUICK SENSOR TOUCH MORE LESS REHEAT COOK COOK STOP/ POWER START TIME CLEAR Figure 4...

  • Page 10: Operating Procedures

    MODEL 721.69252990 721.69259990 7. OPERATING PROCEDURES A. OVEN CONTROL PANEL Display Window- Shows: * Time of day. * Cooking time. * Cooking power level. It also function as a Quick Touch countdown timer Pre-set timing used for when cooking. certain food items.
  • Page 11 MODEL 721.69252990 721.69259990 B. PANEL INSTRUCTIONS The entire operation is done by simple touch control pads. (1) DISPLAY WINDOW (5) POWER Key The display includes a clock and indicators to tell you Used to select cooking power level. time of day, cooking time setting and cooking functions selected.
  • Page 12 MODEL 721.69252990 721.69259990 C. EASY USE CHART (1) CLOCK (5) KITCHEN TIMER 1. Touch STOP/CLEAR. 1. Touch STOP/CLEAR. 2. Touch CLOCK. 2. Touch KITCHEN TIMER. 3. Touch numbers for correct time of day. 3. Touch correct numbers for time. 4. Touch START.

  • Page 13: Procedure For Measuring Microwave Energy Leakage

    MODEL 721.69252990 721.69259990 8. PROCEDURE FOR MEASURING MICROWAVE ENERGY LEAKAGE B. MEASURING MICROWAVE ENERGY LEAKAGE A. CAUTIONS (1) Pour 275 15cc of 20 5 C water in a beaker which is (1) Be sure to check a microwave emission prior to...
  • Page 14 MODEL 721.69252990 721.69259990 D. MEASUREMENT WITH A FULLY ASSEMBLED G. POWER OUTPUT MEASUREMENT OVEN (1) Fill the test beaker with 59 ˚F(15 ˚C) ~ 75 ˚F(24 ˚C) 1 liter tap water. (1) After all components, including the outer panels, are...

  • Page 15: Disassembly Instructions

    MODEL 721.69252990 721.69259990 9. DISASSEMBLY INSTRUCTIONS (6) Pull down and remove the circuit board from the control panel. IMPORTANT NOTES: (7) Remove the F.P.C connector from the terminal UNIT MUST BE DISCONNECTED FROM ELEC- socket. TRICAL OUTLET WHEN MAKING REPAIRS, RE- PLACEMENTS, ADJUSTMENTS AND CONTIN-UITY CHECKS.
  • Page 16 MODEL 721.69252990 721.69259990 C. DOOR GROSS ASSEMBLY REMOVAL Remove choke cover cap (1) Open the door. (2) Remove the choke cover cap very carefully with a flat- blade screwdriver. CAUTION : Be careful not to damage door seal plate with the screwdriver.
  • Page 17 MODEL 721.69252990 721.69259990 D. MAGNETRON REMOVAL E. SUCTION GUIDE MAIN ASSEMBLY (1) Disconnect the wire lead from the magnetron. NOTE: To repair any of them, the Suction Guide Main (2) Carefully remove the mounting screws holding the ASS’Y should be removed first.
  • Page 18 MODEL 721.69252990 721.69259990 F. FAN MOTOR ASSEMBLY REMOVAL H. REMOVING SENSOR 1) Disconnect the leadwire from PCB Assembly. NOTE: To repair any of them, the Suction Guide Main 2) Remove a screw securing the sensor duct. ASS’Y should be removed first.

  • Page 19: High Voltage Capacitor And Diode Removal

    MODEL 721.69252990 721.69259990 I. HIGH VOLTAGE CAPACITOR AND DIODE REMOVAL K. INTERLOCK SYSTEM (1) Discharge the high voltage capacitor. (1) INTERLOCK MECHANISM (2) Disconnect the wire lead from the high voltage capacitor. The door lock mechanism is a device which has been...

  • Page 20: Interlock Continuity Test

    MODEL 721.69252990 721.69259990 10. INTERLOCK CONTINUITY TEST WARNING : FOR CONTINUED PROTECTION AGAINST EXCESSIVE RADIATION EMISSION, REPLACE ONLY WITH IDENTICAL REPLACEMENT PARTS. TYPE NO. SZM-V 16-FA-63 OR VP-533A-OF FOR PRIMARY SWITCH TYPE NO. SZM-V 16-FA-62 OR VP-532A-OF FOR MONITOR SWITCH TYPE NO.

  • Page 21: Test And Checkout Procedures, And Troubleshooting

    MODEL 721.69252990 721.69259990 11. TEST AND CHECKOUT PROCEDURES, 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 WIRE LEADS FROM THE PRIMARY WINDING OF THE HIGH VOLTAGE TRANSFORMER.
  • Page 22 MODEL 721.69252990 721.69259990 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. HIGH VOLTAGE Measure the resistance.

  • Page 23: Test Procedure

    MODEL 721.69252990 721.69259990 COMPONENTS TEST PROCEDURE RESULTS Check for continuity of relay 2 with an ohm- RELAY 2 POWER meter. LEVEL (Remove wire leads from relay 2 and operate the unit.) 4 sec 18 sec 6 sec 16 sec 8 sec...

  • Page 24: Checkout Procedures

    MODEL 721.69252990 721.69259990 B. CHECKOUT PROCEDURES (1) CHECKOUT PROCEDURES FOR FUSE BLOWING CAUTION: REPLACE BLOWN FUSE WITH 20 AMPERE FUSE. PROBLEMS CAUSES Fuse blows immediately after Improper operation of the primary interlock, the door is closed. secondary interlock switches and/or the interlock monitor switch.
  • Page 25 MODEL 721.69252990 721.69259990 (2) CHECKOUT PROCEDURES FOR RELAY - PROBLEM (A) - FAN motor and 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...
  • Page 26 MODEL 721.69252990 721.69259990 (3) CHECKOUT PROCEDURES FOR CIRCUIT BOARD The following symptoms indicate a defective circuit board. (1) The start function fails to operate but the high (4) Some segments of one or more digits do not light up, voltage Systems, the interlock switches, the door or they continue to light up, or segments light when sensing and the relay check good.

  • Page 27: Troubleshooting

    MODEL 721.69252990 721.69259990 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.
  • Page 28 MODEL 721.69252990 721.69259990 (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.
  • Page 29 MODEL 721.69252990 721.69259990 (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 Replace fuse, Check continuity 1. Fuse blows. Continuity. monitor switch.
  • Page 30 MODEL 721.69252990 721.69259990 (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.
  • Page 31 MODEL 721.69252990 721.69259990 (TROUBLE 5) No microwave oscillation even though oven lamp and fan motor run. (Display operates properly) CONDITION CHECK RESULT CAUSE REMEDY No microwave Defective PCB Replace PCB Disconnect the No continuity. oscillation. assembly. assembly. wire leads from...
  • Page 32 KENMORE MICROWAVE OVEN MODEL NO. 721.69252990 721.69259990 INTRODUCTION SENSOR PARTS OVEN CAVITY PARTS INTERIOR PARTS SUCTION GUIDE MAIN PARTS DOOR PARTS BASE PLATE PARTS CONTROL PANEL PARTS *** ALL SERVICE ON MICROWAVE OVENS SHOULD BE PERFORMED BY A QUALIFIED TECHNICIAN USING APPROVED TESTING EQUIPMENT.
  • Page 33 DRAWING NO: 1 KENMORE MICROWAVE OVEN MODEL NO. 721.69252990 721.69259990 DOOR PARTS 13581A 13552A 13536A 13213A 13352A 14026A 14970A 13720D *** ALL SERVICE ON MICROWAVE OVENS SHOULD BE PERFORMED BY A QUALIFIED TECHNICIAN USING APPROVED TESTING EQUIPMENT. CUSTOMERS SHOULD NOT ATTEMPT TO REPLACE PARTS IDENTIFIED BY A TRIPLE ASTERISK(***) JUNE.
  • Page 34 DRAWING NO: 1 KENMORE MICROWAVE OVEN MODEL NO. 721.69252990 721.69259990 DOOR PARTS (See Illustration “DOOR PARTS”) N.S.P (NOT SERVICE PART): THESE PARTS ARE NOT AVAILABLE AS REPAIR PARTS BECAUSE THEY ARE TOO COSTLY OR NOT PRACTICAL TO REPLACE OR NEVER EXPECTED TO FAIL DURING THE LIFE EXPECTANCY OF THE UNIT.
  • Page 35 DRAWING NO: 2 KENMORE MICROWAVE OVEN MODEL NO. 721.69252990 721.69259990 CONTROLLER PARTS 24781M 23550D 268711 23572A WTT028 26638A WTP018 24510L 24970A 250201 *** ALL SERVICE ON MICROWAVE OVENS SHOULD BE PERFORMED BY A QUALIFIED TECHNICIAN USING APPROVED TESTING EQUIPMENT. CUSTOMERS SHOULD NOT ATTEMPT TO REPLACE PARTS IDENTIFIED BY A TRIPLE ASTERISK(***) JUNE.
  • Page 36 DRAWING NO: 2 KENMORE MICROWAVE OVEN MODEL NO. 721.69252990 721.69259990 CONTROL PANEL PARTS (See Illustration “CONTROLLER PARTS”) N.S.P (NOT SERVICE PART): THESE PARTS ARE NOT AVAILABLE AS REPAIR PARTS BECAUSE THEY ARE TOO COSTLY OR NOT PRACTICAL TO REPLACE OR NEVER EXPECTED TO FAIL DURING THE LIFE EXPECTANCY OF THE UNIT.
  • Page 37 DRAWING NO: 3 KENMORE MICROWAVE OVEN MODEL NO. 721.69252990 721.69259990 OVEN CAVITY PARTS 33112U WTT020 WSZ185 33052M 340511 WTT020 33461Z 34036W 33390G 36549S 35889A WTP013 *** ALL SERVICE ON MICROWAVE OVENS SHOULD BE PERFORMED BY A QUALIFIED TECHNICIAN USING APPROVED TESTING EQUIPMENT. CUSTOMERS SHOULD NOT ATTEMPT TO REPLACE PARTS IDENTIFIED BY A TRIPLE ASTERISK(***) JUNE.
  • Page 38 DRAWING NO: 3 KENMORE MICROWAVE OVEN MODEL NO. 721.69252990 721.69259990 OVEN CAVITY PARTS (See Illustration “OVEN CAVITY PARTS”) N.S.P (NOT SERVICE PART): THESE PARTS ARE NOT AVAILABLE AS REPAIR PARTS BECAUSE THEY ARE TOO COSTLY OR NOT PRACTICAL TO REPLACE OR NEVER EXPECTED TO FAIL DURING THE LIFE EXPECTANCY OF THE UNIT.
  • Page 39 DRAWING NO: 4 KENMORE MICROWAVE OVEN MODEL NO. 721.69252990 721.69259990 LATCH BOARD PARTS 33461Z WSZ085 43500A 466002 43501A 466003 466001 *** ALL SERVICE ON MICROWAVE OVENS SHOULD BE PERFORMED BY A QUALIFIED TECHNICIAN USING APPROVED TESTING EQUIPMENT. CUSTOMERS SHOULD NOT ATTEMPT TO REPLACE PARTS IDENTIFIED BY A TRIPLE ASTERISK(***) JUNE.
  • Page 40 DRAWING NO: 4 KENMORE MICROWAVE OVEN MODEL NO. 721.69252990 721.69259990 LATCH BOARD PARTS (See Illustration “OVEN CAVITY PARTS”) N.S.P (NOT SERVICE PART): THESE PARTS ARE NOT AVAILABLE AS REPAIR PARTS BECAUSE THEY ARE TOO COSTLY OR NOT PRACTICAL TO REPLACE OR NEVER EXPECTED TO FAIL DURING THE LIFE EXPECTANCY OF THE UNIT.
  • Page 41 DRAWING NO: 5 KENMORE MICROWAVE OVEN MODEL NO. 721.69252990 721.69259990 OVEN INTERIOR PARTS 55006F WSZ002 568771 56411A 50FZZA 56930V WTT028 56549F 54974S WSZ002 55900A WTT037 56912B WSZ002 WSZ002 50CZZH 56851D 56324A 55262A WTT028 WSZ002 54810C 948502 *** ALL SERVICE ON MICROWAVE OVENS SHOULD BE PERFORMED BY A QUALIFIED TECHNICIAN USING APPROVED TESTING EQUIPMENT.
  • Page 42 DRAWING NO: 5 KENMORE MICROWAVE OVEN MODEL NO. 721.69252990 721.69259990 OVEN INTERIOR PARTS (See Illustration “LATCH BOARD”) N.S.P (NOT SERVICE PART): THESE PARTS ARE NOT AVAILABLE AS REPAIR PARTS BECAUSE THEY ARE TOO COSTLY OR NOT PRACTICAL TO REPLACE OR NEVER EXPECTED TO FAIL DURING THE LIFE EXPECTANCY OF THE UNIT.
  • Page 43 DRAWING NO: 6 KENMORE MICROWAVE OVEN MODEL NO. 721.69252990 721.69259990 BASE PLATE PARTS 56170D 63303A 65006B 948503 WTTO21 65006B WSZ002 WSZ002 *** ALL SERVICE ON MICROWAVE OVENS SHOULD BE PERFORMED BY A QUALIFIED TECHNICIAN USING APPROVED TESTING EQUIPMENT. CUSTOMERS SHOULD NOT ATTEMPT TO REPLACE PARTS IDENTIFIED BY A TRIPLE ASTERISK(***) JUNE.
  • Page 44 DRAWING NO: 6 KENMORE MICROWAVE OVEN MODEL NO. 721.69252990 721.69259990 BASE PLATE PARTS (See Illustration “BASE PLATE PARTS ”) N.S.P (NOT SERVICE PART): THESE PARTS ARE NOT AVAILABLE AS REPAIR PARTS BECAUSE THEY ARE TOO COSTLY OR NOT PRACTICAL TO REPLACE OR NEVER EXPECTED TO FAIL DURING THE LIFE EXPECTANCY OF THE UNIT.
  • Page 45 DRAWING NO: 7 KENMORE MICROWAVE OVEN MODEL NO. 721.69252990 721.69259990 SENSOR PARTS WTT021 56501A 54974T WTP002 *** ALL SERVICE ON MICROWAVE OVENS SHOULD BE PERFORMED BY A QUALIFIED TECHNICIAN USING APPROVED TESTING EQUIPMENT. CUSTOMERS SHOULD NOT ATTEMPT TO REPLACE PARTS IDENTIFIED BY A TRIPLE ASTERISK(***) JUNE.
  • Page 46 DRAWING NO: 7 KENMORE MICROWAVE OVEN MODEL NO. 721.69252990 721.69259990 SENSOR PARTS (See Illustration “SENSOR PARTS ”) N.S.P (NOT SERVICE PART): THESE PARTS ARE NOT AVAILABLE AS REPAIR PARTS BECAUSE THEY ARE TOO COSTLY OR NOT PRACTICAL TO REPLACE OR NEVER EXPECTED TO FAIL DURING THE LIFE EXPECTANCY OF THE UNIT.
  • Page 47 DRAWING NO: 11 KENMORE MICROWAVE OVEN MODEL NO. 721.69252990 721.69259990 POWER AND CONTROL CIRCUIT BOARD COMPONENT SIDE SOLDER SIDE JUNE. 1999 -16-...
  • Page 48 DRAWING NO: 11 KENMORE MICROWAVE OVEN MODEL NO. 721.69252990 721.69259990 POWER AND CONTROL CIRCUIT BOARD (See Illustration “POWER AND CONTROL CIRCUIT BOARD”) N.S.P (NOT SERVICE PART): THESE PARTS ARE NOT AVAILABLE AS REPAIR PARTS BECAUSE THEY ARE TOO COSTLY OR NOT PRACTICAL TO REPLACE OR NEVER EXPECTED TO FAIL DURING THE LIFE EXPECTANCY OF THE UNIT.
  • Page 49 P/NO: 3828W5S1194 Printed in Korea...

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