Sharp manual Table Of Contents, MICROWAVE DRAWER MODELS MMD24SMMD24B, S38M289MMD24S

Page 1
MMD24S
MMD24S

MMD24B

 SERVICE MANUAL SERVICE MANUAL

S38M289MMD24S

MICROWAVE DRAWER

MODELS

MMD24SMMD24B

In the interest of user-safety the unit should be restored to its original condition and only parts identical to those specified should be used.

WARNING TO SERVICE PERSONNEL:

This service manual is intended for use by persons having electrical and mechanical training and a level of knowledge of these subjects generally considered acceptable in the appliance repair trade. Sharp Electronics Corporation cannot be responsible, nor assume any liability, for injury or damage of any kind arising from the use of this manual.

Microwave ovens contain circuitry capable of producing very high voltage and current. Contact with the following parts may result in a severe, possibly fatal, electrical shock. (High Voltage Capacitor, High Voltage Power Transformer, High Voltage Rectifier and Heat sink etc., and Magnetron, High Voltage Harness etc..)

TABLE OF CONTENTS

 

 

Page

PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO

 

AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY

INSIDE FRONT COVER

BEFORE SERVICING

INSIDE FRONT COVER

WARNING TO SERVICE PERSONNEL

3

MICROWAVE MEASUREMENT PROCEDURE

4

FOREWORD AND WARNING

5

PRODUCT SPECIFICATIONS

6

SCHEMATICS

10

TEST PROCEDURES

11

TOUCH CONTROL PANEL ASSEMBLY

19

MICROWAVE DRAWER DISASSEMBLY

27

WIRING DIAGRAMS

33

PRINTED WIRING BOARDS

34

PARTS LIST

38

PACKING AND ACCESSORIES

43

This document has been published to be used for after sales

service only. The contents are subject to change without

notice.

 

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Contents WARNING TO SERVICE PERSONNEL TABLE OF CONTENTSWARNING TO SERVICE PERSONNEL MICROWAVE MEASUREMENT PROCEDUREBEFORE SERVICING After repairing WARNING TO SERVICE PERSONNELBefore Servicing When the testing is completedB. Preparation for testing MICROWAVE MEASUREMENT PROCEDUREA. Requirements C. Leakage test1440 Bridge Gate Dr Diamond Bar, CA DANGERSERVICE MANUAL If provided, Vent Hood, Fan assembly, Cooling Fan MotorDESCRIPTION MICROWAVE DRAWER SPECIFICATIONGROUNDING INSTRUCTIONS GENERAL INFORMATIONOPERATION POWER LEVEL P-0 TO P-90 COOKINGDESCRIPTION OF OPERATING SEQUENCE OFF CONDITIONCooking Sequence SENSOR COOKING CONDITIONMICROWAVE CLOSED, COOK OFF CONDITTION SCHEMATIC OFF CONDITIONDOOR PROCEDURE TEST PROCEDURESA TOUCH CONTROL PANEL ASSEMBLY TEST Before testingB KEY UNIT TEST COMPONENT TESTC RELAY TEST DEFROST TEST Check supply voltage and oven power cordSTEPS The rated AC voltage is not present betweenF AH SENSOR TEST Checking the initial sensor cooking condition TESTING METHOD FOR AH SENSOR AND/OR CONTROL UNITWater load cooking test R1, R2 22Ω ± 1% 1/2W R3 4.3kΩ ± 5% 1/4W R4 1MΩ ± 5% 1/4W CHECKING CONTROL UNITG MAGNETRON ASSEMBLY TEST Refer to the disassembly instructions found on PageMICROWAVE OUTPUT POWER H THERMAL CUT-OUT TESTJ STOP SWITCH TEST I SECONDARY INTERLOCK SWITCH TESTK MONITOR SWITCH TEST L BLOWN MONITOR FUSE TEST M POWER TRANSFORMER TESTControl Unit and Power Unit TOUCH CONTROL PANEL ASSEMBLY4 Reset Circuit 5 Indicator CircuitPower source voltage 0V GND DESCRIPTION OF LSI IC-1Internal clock oscillation frequency setting input Power source voltage +5VSegment data signal SignalSignal coming from touch key Signal similar to P23Common relay driving signal. Square Waveform 60Hz Magnetron high-voltage circuit driving signalSignal to sound buzzer Signal to synchronize LSI with commercial power source frequencyventilation opening for sensing HUMIDITY SENSOR CIRCUIT1 Structure of Humidity Sensor 2 Operational Principle of Humidity Sensor1 Servicing the touch control panel with power supply of the oven TOUCH CONTROL PANEL SERVICING4. Other Precautions 2. Servicing of Touch Control Panel2. Using lead-free wire solder PRECAUTIONS FOR USING LEAD-FREE SOLDER1. Employing lead-free solder 3. SolderingWARNING FOR WIRING COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDUREWARNING AGAINST HIGH VOLTAGE To prevent an electric shock, take the following pre- cautionsMICROWAVE DRAWER DISASSEMBLY Un-hook/Attach Black AC Wire to Top Terminal POWER CORD REPLACEMENTUn-hook/Attach White AC Wire to Bottom Terminal Un-hook/Attach Ground to metal Tab on Back PlateSTOP SWITCH, SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH ADJUSTMENT STOP SWITCH, SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH REMOVALRe-install After adjustment, check the followingDRAWER SUPPORT ANGLE REMOVAL DRAWER ASSEMBLY AND CHOKE REMOVALDRAWER/SLIDE RAIL REMOVAL 1. Follow the Microwave Drawer disassembly as previouslySWITCH ANGLE REMOVAL SWITCH ANGLE REMOVAL/ADJUSTMENTACTUATOR REMOVAL/ADJUSTMENT Actuator adjustmentBottom cover AUTO DRAWER GEAR REMOVAL/INSTALLATIONRACK GEAR REMOVAL Installationto Back Plate HIGH VOLTAGE COMPONENTSMICRO Figure S-2. Power Unit CircuitFM A CN-ACONTROL UNITUNIT F G H2.5A Figure S-4. Printed Wiring Board of Power UnitA B C D E F G H UnitControlof 5.PrintedWiringBoardCOPYRIGHT 2008 BY DACOR, INC ALL RIGHTS RESERVED