1
INTRODUCTION
This Microwave Oven Service Manual is printed in a loose-leaf format. Each part is divided into sections relating
to a general group of components and each section is subdivided into various parts describing a particular
component or service procedure.
The subdividing of the subject matter plus the loose leaf form will facilitate the updating of the manual as new or
revised components and service procedures are introduced.
Each page of this service manual will be identified in the lower right hand corner and, as new or revised pages
are published, it will be easy to keep the manual up to date by following the filing instructions on the cover letter.
This Service Manual is a valuable service tool and care should be taken to keep it up to date by prompt and
proper filling of subsequent pages as they are issued.
CONTENTS
SAFETY PRECAUTIONS..........................................................................................................................................2
1
THE HEATING PRINCIPLE OF MICROWAVE..................................................................................................2
THE STRUCTURE AND WORKING PRINCIPLE OF MICROWWAVE OVEN.........................................................4
2.1
HIGH VOLTAGE RECTIFYING CIRCUIT. ..........................................................................................4
2.2
MICROWAVE GENERATER...............................................................................................................4
2.3
COOLING SYSTEM............................................................................................................................5
2.4
ELECTRIC CONTROL SYSTEM........................................................................................................5
3
TYPICAL CIRCUIT ANALYASIS OF MICROWAVE OVEN................................................................................8
4
HOW TO ASSEMBLE AND DISASSEMBLE MICROWAVE OVEN COMPONENTS .......................................9
4.1
THE CABINET ....................................................................................................................................9
THE DOOR COMBINATION ..............................................................................................................................9
4.3
THE CONTROL PANEL AND THE DOOR RELEASE MECHANISM. .............................................10
4.4
THE MAGNETRON. .........................................................................................................................11
4.5
THE TRANSFORMER......................................................................................................................11
4.6
THE FAN MOTOR. ...........................................................................................................................12
4.7
THE CAPACITOR. ............................................................................................................................13
4.8
THE DIODE. .....................................................................................................................................13
4.9
THE TURNTABLE COMBINATIOM. .................................................................................................13
4.10
THE DOOR SAFTY INTERLOCKS. .................................................................................................14
THE CONTROL PANEL OF A TYPICAL MICROWAVE OVEN .......................................................................15
5
BREAKDOWN ANALYSIS AND THE MEANS OF OVERHAULING ...............................................................15
5.1
EXAMINING THE BREAKDOWN CAUSES.....................................................................................15
SPOT EXAMINING STEPS OF THE MICROWAVE OVEN ............................................................................16
5.3
REPAIRING METHOD OF SEVERAL BREAKDOWN .....................................................................18
5.4
THE CHARACTERS REQUIREMENTS OF MICROWAVE AFTER IT HAS BEEN REPAIRED......20
6
CRITICAL PARTS SERVICING .......................................................................................................................21
6.1
IMPORTANT THINGS TO DO PRIOR TO CRITICAL PARTS SERVICING:....................................21
6.2
Interlock Assembly Replacement and Adjustment. ..........................................................................21
7
COMMON BREAKDOWN OF MICROWAVE OVEN AND MEANS OF REPAIRING......................................21
