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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. Adjustment Procedures  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

2. Precautions on Installation  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3. General Precautions in Use  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

4. Trial Operation  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

5. Specifications  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

6. Overall Circuit Diagram  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8

7. Operating Procedures  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-11

8. Procedure for Measuring Microwave Energy Leakage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-13

9. Disassembly Instructions  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-18

10. Interlock Continuity Test  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

11. Test and Checkout Procedures, and Troubleshooting

A. Test Procedures  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-22

B. Checkout Procedures  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23-25

C. Troubleshooting  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26-30

Summary of Contents for 721.69252990

Page 1: ...DIVISION 20 BASIC FIELD MANUAL FOR MICROWAVE OVEN MODEL 721 69252990 721 69259990 June 1999 MODEL 721 69252990 721 69259990...

Page 2: ...ent integrity and connections d Any defective or misadjusted components in the interlock monitor door seal and microwave generation and transmission systems shall be repaired adjusted by procedures de...

Page 3: ...SERVICE INFORMATION TABLE OF CONTENTS 1 Adjustment Procedures 3 2 Precautions on Installation 5 3 General Precautions in Use 5 4 Trial Operation 5 5 Specifications 6 6 Overall Circuit Diagram 7 8 7 O...

Page 4: ...low all steps in order ADJUST THE LATCH AND SWITCH CLOSINGS 3 Loosen the two screws holding the plastic latch board as shown 4 With the oven door closed tightly move the latch board upward toward the...

Page 5: ...D INTERLOCK MONITOR SWITCH PRIMARY INTERLOCK SWITCH SECONDARY INTERLOCK SWITCH SCREW SCREW LATCH LATCH BOARD 0 1 64 0 1 64 DOOR LATCH A B RELEASE LEVER C Figure 1 a Figure 1 b 4 MODEL 721 69252990 721...

Page 6: ...The unit will begin cooking and the display window will show the time counting down by seconds E After about 5 minutes make sure the primary interlock switch the secondary interlock switch and the in...

Page 7: ...tch Interlock Monitor Magnetron 2M246 High Voltage Capacitor Capacitor 1 00 F 2 1KV Ac High Voltage Diode 350mA 9 0KV Cavity Lamp 125V 20W Timer Digital up to 99 mm 99 sec in each cooking stage Tray T...

Page 8: ...ONS ARE SUBJECT TO CHANGE FOR IMPROVEMENT N L 1 2 3 4 5 6 7 8 OL FM TTM 1 2 3 4 5 6 7 8 WH SYMBOL NOTE 1 DOOR IS OPEN 2 RS SENSING ELEMENT RC COMPENSATING ELEMENT 3 WIRE COLOR COLOR WHITE BLACK YELLOW...

Page 9: ...BOARD 8 N C QUICK ON COOK TIME 2 KITCHEN TIMER MORE 9 6 USER CHOICE N C 8 5 AUTO DEFROST QUICK TOUCH COOK START 4 SENSOR COOK SENSOR REHEAT STOP CLEAR 3 SENSOR POPCORN N C POWER 1 1 8 9 10 11 2 3 4 5...

Page 10: ...hen you touch a key on the control panel to indicate that you have entered a setting Clock Auto Defrost Kitchen Timer You can use your microwave oven as a timer Numbers Used to enter the Time of day C...

Page 11: ...CLOCK Key Used in setting CLOCK 4 AUTO DEFROST key DEFROST MEAT POULTRY FISH Used in setting AUTO DEFROST 5 POWER Key Used to select cooking power level 6 STOP CLEAR Key Used to stop the oven or clea...

Page 12: ...uch STOP CLEAR 2 Touch START more than 2 seconds 5 KITCHEN TIMER 1 Touch STOP CLEAR 2 Touch KITCHEN TIMER 3 Touch correct numbers for time 4 Touch START 6 QUICK ON COOKING 1 Touch STOP CLEAR 2 Touch Q...

Page 13: ...rt measuring of an unknown field to assure safety for operating personnel from radiation leakage NOTE The standard is 5mW cm sq while in the customer s home 1mW cm sq stated here is manufacturer s own...

Page 14: ...the service invoice 2 Should the microwave energy leakage not be more than 1mW cm sq after determining that all parts are in good condition functioning properly and genuine replacement parts which are...

Page 15: ...8 1 Remove three screws from the rear section 2 Remove one screw from the side section 3 Push the outer case back about 1 inch 3cm 4 Lift the case from the set B REMOVING POWER AND CONTROL CIRCUIT BOA...

Page 16: ...e door check for microwave energy leakage with a survey meter Microwave energy must be below the limit of 5 mW cm sq with a 275 ml water load 3 When mounting the door assembly to the oven assembly be...

Page 17: ...of 5 mW cm2 With a 275 ml water load Make sure that gasket is rigidly attached to the magnetron To prevent microwave leakage tighten the mounting screws properly making sure there is no gap between t...

Page 18: ...MOVAL NOTE To repair any of them the Suction Guide Main ASS Y should be removed first 1 Disconnect the wire lead from fan motor 2 Remove the fan 3 Remove the two screws holding the fan motor assembly...

Page 19: ...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 microw...

Page 20: ...uld indicate an closed circuit When the secondary switch operation is abnormal make the necessary adjustment or replace the switch only with the same type of switch C MONITOR SWITCH TEST Disconnect th...

Page 21: ...ed MAGNETRON Wire leads removed 1 Measure the resistance Ohm meter scale Rx1 and Rx100 Primary winding Secondary winding Filament winding 2 Measure the resistance Ohm meter scale Rx1000 Primary windin...

Page 22: ...Measure the continuity Forward Ohm meter scale Rx10000 Measure the continuity Reverse Ohm meter scale Rx10000 Normal Momentarily indicates several ohms and then gradually returns to infinite Normal I...

Page 23: ...0 sec Normal Approx 65 80 ohm Abnormal Infinite or several ohm Normal Approx 2 4K ohm Abnormal Infinite or several ohm Normal Approximately BK RD 6 2 Kohm RD WH 3 1 Kohm BK WH 3 1 Kohm Abnormal Infin...

Page 24: ...he high voltage transformer the high voltage capacitor including the diode the magnetron the blower motor or the circuit board PROBLEMS CAUSES NOTES If the fuse is blown by an improper switch operatio...

Page 25: ...the circuit board does the unit still operate GOOD GOOD Replace the circuit board PROBLEM B FAN motor and oven lamp turn on When the door is closed and START key is touched Check the interlock switch...

Page 26: ...inuously operates 3 The buzzer does not sound or continues to sound 4 Some segments of one or more digits do not light up or they continue to light up or segments light when they should not 6 Wrong fi...

Page 27: ...atic charge built up in your body Micom model only CONDITION Microwave oven does not work Inserting many plugs into one outlet and using them at the same time blown fuse or breaker Microwave oven plug...

Page 28: ...n after setting cooking cycle 11 Display time of day does not reappear when cooking is finished TROUBLE 1 The following visual conditions indicate a probable defective control circuit CONDITION CHECK...

Page 29: ...hes and RELAY RY2 of P C B Assembly Check continuity of monitor switch with door closed Check continuity of primary switch with door opened Disconnect one side of the wire lead connected from transfor...

Page 30: ...t oven does not start cooking while desired program times are set and START pad is touched TROUBLE 4 Oven seems to be operating but little heat is produced in oven load NOTE Simple test of power outpu...

Page 31: ...ntinuity relay 2 Operate the unit Abnormal Defective high voltage capacitor Replace high voltage capacitor Normal Check high vol tage capacitor Abnormal Defective high voltage diode Replace high volta...

Page 32: ...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 DOOR PARTS CONTROL PANEL...

Page 33: ...9990 DOOR PARTS 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 ASTER...

Page 34: ...E 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 ITEMS NOT ILLUSTRATED ALL SERVICE ON MICROWAVE OVENS SHOULD B...

Page 35: ...AWING NO 2 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 2...

Page 36: ...T 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 ITEMS NOT ILLUSTRATED ALL SERVICE ON MICROWAVE OVEN...

Page 37: ...ICIAN USING APPROVED TESTING EQUIPMENT CUSTOMERS SHOULD NOT ATTEMPT TO REPLACE PARTS IDENTIFIED BY A TRIPLE ASTERISK 33052M 340511 36549S WTP013 33390G WTT020 WSZ185 33112U 35889A WTT020 33461Z 34036W...

Page 38: ...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 ITEMS NOT ILLUSTRATED ALL SERVICE ON MICROWAVE OVENS...

Page 39: ...PARTS 8 DRAWING NO 4 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...

Page 40: ...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 ITEMS NOT ILLUSTRATED ALL SERVICE ON MICROWAVE OVENS...

Page 41: ...CUSTOMERS SHOULD NOT ATTEMPT TO REPLACE PARTS IDENTIFIED BY A TRIPLE ASTERISK WSZ002 WSZ002 WTT028 WSZ002 WTT028 WSZ002 WTT037 50CZZH 56324A 54810C 948502 56851D 55900A 56549F 56930V 568771 54974S 550...

Page 42: ...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 ITEMS NOT ILLUSTRATED ALL SERVICE ON MICROWAVE OVENS...

Page 43: ...TS 12 DRAWING NO 6 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 AS...

Page 44: ...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 ITEMS NOT ILLUSTRATED ALL SERVICE ON MICROWAVE OVENS...

Page 45: ...0 SENSOR PARTS 14 DRAWING NO 7 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...

Page 46: ...ILABLE 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 ITEMS NOT ILLUSTRATED ALL SERVICE ON MICROWAVE OVENS SHO...

Page 47: ...KENMORE MICROWAVE OVEN MODEL NO 721 69252990 721 69259990 POWER AND CONTROL CIRCUIT BOARD 16 DRAWING NO 11 COMPONENT SIDE SOLDER SIDE JUNE 1999...

Page 48: ...E 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 ITEMS NOT ILLUSTRATED ALL SERVICE ON...

Page 49: ...P NO 3828W5S1194 Printed in Korea...

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