Intro Introduction by the author, John C Gallawa. EMnrgy Understanding the basic principles of electromagnetic energy

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3 Video Library Intro Introduction by the author, John C Gallawa EMnrgy Understanding the basic principles of electromagnetic energy FreqSpec Description of the electromagnetic frequency spectrum showing the frequency range of microwaves used in microwave ovens HowCook Learn how and why microwaves cook food Leakage Determining what is a safe distance from an operating microwave oven? Caution Important information about safety and accidental electrocution when working around electricity CapDschg How to properly discharge the high-voltage capacitor GrndTst How to check the electrical outlet for proper grounding and polarity Triac Understanding the circuit operation of the triac in a microwave oven TriacTst How to test the triac Intrlock Understanding the purpose of the interlock monitor circuit and how it works SurgProt Find out about all about the different types of surge protectors that are used in microwave ovens MagTest How to test the magnetron TfmrTst How to test the high-voltage transformer DiodeTst How to test the high-voltage diode Arcing Why the waveguide cover starts to arc and how to repair it Convectn Discover the difference between convection heating and conventional heating and how the convection mode works OTRSvc How to gain service access to over-the-range models

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5 Table of Contents Precautions Preface Part 1 Introduction to Microwave Energy Chapter One A Brief History of Microwave Oven Development Chapter Two Basic Principles of Microwave Energy 2.1 Introduction 2.2 Ionizing Radiation 2.3 Non-Ionizing Radiation 2.4 Two Thousand Four Hundred and Fifty Million Hertz 2.5 How Food Is Cooked By Microwaves 2.6 Microwave Penetration 2.7 Proportional Relationships 2.8 Microwaves and Metal 2.9 Arcing and Backfeeding Chapter Three Safety of Microwave Energy: An Objective Discussion 3.1 Introduction 3.2 Microwaves How Dangerous Are They? 3.3 Measuring Microwaves 3.4 Soviet Standards 3.5 What Are Safe Levels of Exposure? 3.6 How Far Away Is Safe? 3.7 Microwaves and Cardiac Pacemakers 3.8 Radiation Injuries From Microwave Ovens? 3.9 Color Television Emissions Part 2 Preparing to Repair Microwave Ovens Chapter Four Safety Considerations 4.1 Introduction 4.2 Safety Around Line Voltage 4.3 Warning High Voltage 4.4 Warning Possible RF Exposure 4.5 On-The-Job Safety 4.6 Lift So As To Be Able To Lift Again Chapter Five A Well-Organized Shop 5.1 Introduction 5.2 Tools and Test Equipment Hand Tools Additional Equipment and Supplies Test Equipment 5.3 Special Tools 5.4 Homemade Tools, Miscellaneous Equipment and Supplies 5.5 Supplies Chapter Six Rendering In-Home Service with Confidence 6.1 Introduction 6.2 Working Under Scrutinizing Eyes 6.3 Quality of Workmanship Part 3 Description of Operation Chapter Seven The High-Voltage System 7.1 Introduction 7.2 Magnetron Tube 7.3 Basic Magnetron Operation Effect of The Magnetic Field Resonant Circuits The Waveguide RF Capacitors Cooling Fins Proper Phasing Magnetron Life Expectancy 7.4 Transformers High-Voltage Transformer Fig Filament Transformer 7.5 The High-Voltage Capacitor and Diode The Voltage-Doubler Circuit The High-Voltage Capacitor The High-Voltage Diode

6 7.6 The High-Voltage Circuit Voltage Doubler Operation Half-Wave Voltage Doubter Full-Wave Voltage Doubler Chapter Eight Control System 8.1 Introduction 8.2 Timers 8.3 Pushbutton Timers 8.4 Add Integrated Circuits 8.5 Microprocessors and Computer Electronics 8.6 Electronic Timers Past and Present Glass Touch Panels Membrane Switch Panels 8.7 Typical Electronic Control Systems Description of Generalized Control Panel Circuit Control Transformer The Cook Relay 8.8 Standby, Idle, and Cook Example 8.8.1: Description of Start- Up, Holding and Shut-Down Operation Example 8.8.2: Description of Start- Up, Holding and Shut-Down Example 8.8.3: Description of Start-Up, Idle and Cooking Operation 8.11 Output Power Control 8.12 Primary Side Duty Control Mechanical Controllers Solid State Controllers 8.13 Triacs Triac Drive Circuit System Operation Additional Triac Information 8.14 Secondary (High-Voltage) Side Duty Control 8.15 Phase Control Circuit 8.16 Advanced Systems 8.17 Secondary Control By Varying The High-Voltage Potential 8.18 The Probe 8.19 Humidity Sensor Cooking 8.20 Absolute Humidity Sensor 8.21 Infrared Sensor Unit 8.22 Convection Cooking Control 8.23 Additional Control Concepts 8.24 New Cooking Technology Inverter Technology Advantium Speedcooking Using The Power of Light The NCR Microwave Bank An Internet-Ready Computer Built Into A Samsung Net Microwave Chapter Nine Safety and Protection Circuits 9.1 Introduction 9.2 Interlock Switches and Circuits 9.3 Interlock-Monitor Switch 9.4 Interlock Sequencing 9.5 Interlock Protection Postscript 9.6 Additional Switch Applications 9.7 Protection Devices Thermal Protectors Ferrite Isolator Thermal Protectors Non-Resetting Thermal Fuses 9.8 Voltage Protection Devices Varistor Surge Absorbers PTC Resistor 9.9 Fuses 9.10 Magnetron Protection and Failure Detection Chapter Ten Microwave Containment Systems 10.1 Introduction 10.2 The Cooking Cavity 10.3 The Cooking Shelf 10.4 The Waveguide 10.5 The Door Leakage Safety System

7 Chapter Eleven Cooling and Energy Dispersion Systems 11.1 Introduction 11.2 Cooling Systems 11.3 Stirrer, Food Rotatio, Energy Dispersal 11.4 Carousel Or Turntable Systems 11.5 The Rotating Antenna 11.6 Stirrer and Waveguide Covers 11.7 Baffle Systems Part 4 Component Tests, Failures, and Corrective Actions Chapter Twelve High Voltage Components Testing and Failure Modes 12.1 Introduction 12.2 Isolation Test Isolating The Problem Area 12.3 Power Output Check Using A Centigrade Thermometer Power Output Check Using A Fahrenheit Thermometer Increasing Or Decreasing The Output 12.4 Magnetron Failure Modes 12.5 Magnetron Testing Magnetron Plate Current (Ip) Test Analysis of The Plate Current (Lp) Test Results 12.6 Magnetron Replacement Instruction Cross-Reference Guide 12.7 Filament Transformer Testing Filament Transformer Voltage Test Filament Voltage Test Results 12.8 High-Voltage (Also Power Or Plate) Transformer Test 12.9 High-Voltage Capacitor Test Frequency Conversion Diode (Rectifier) Check Diode Installation Checking Halt-Wave Rectifiers Wiring and Connector Considerations Chapter Thirteen Control Components: Tests and Failures 13.1 Testing Basic Electromechanical Timers Operational Timer Motor Check Operational Switch Contact Test Installation Considerations 13.2 Commercial Pushbutton Timers Printed Circuit Board Repair Considerations Operational Test Commercial Electromechanical Pushbutton Timer Resistance Checks 13.3 Solid State Commercial Timers Symptoms That Can Denote A Defective Electronic Timer 13.4 Domestic Control Circuits Checks and Failures 13.5 Mylar (Membrane) Touch Panel Or The Control Panel Which? Membrane Touch Panel Evaluations and Considerations 13.6 Low-Voltage (Control) Transformer and Transmotor Checks 13.7 Warm-Up Relays and Time Delay Circuits Time Delay Board Test Millisecond-Delay Board Test Surge Relay Check 13.8 Start-Up, Shut-Down, and Holding Relays Load Resistor Check

8 Associated Symptoms 13.9 Checking Relays In General General Relay Checkout Procedure Output Power-Control Component Testing Primary Side Power Control Component Testing Solid State Controllers Triac Tests Results and Symptoms Verifying Proper Dc Gate Voltage Gate-Firing Capability Check Results Triac Operational Test Replacement Considerations Amana Solid State Relay (Triac) Test Triac Module Test Results and Symptoms Gate Voltage Verification Auxiliary Module Secondary-Side Power-Control Component Checks Troubleshooting Inverter Power Supplies Checking Power Resistors Temperature Control Probe Testing Sensor Element and Associated Circuitry Test Results of Test # Infrared Sensor Convection and Conventional Cooking Control Heating Element Test Additional Notes On Convection Elements Thermistor Test Chapter Fourteen Safety and Protection Circuits: Tests and Failures 14.1 Introduction 14.2 Door Interlock Switch Test 14.3 Interlock Switch Adjustment 14.4 Amana Latch Solenoid 14.5 Amana Multiprotector Assembly (Fig. 14-5) Replacement of Thermal Fuses 14.6 Checking Thermal Protectors Resettable and Non-resettable Common Causes of Thermal Protector-Related Failures 14.7 Arcing Inside the Waveguide 14.8 Surge Monitor System 14.9 Checking Voltage Protection Devices Foil Patterns and Filter Coils PTC Surge Resistor Test Line Fuse Testing and Fuse Failures Chapter Fifteen Containment Systems: Checks and Failures 15.1 Introduction 15.2 Cleaning The Choke Cavity 15.3 Rust and Corrosion In The Cooking Cavity Damage To Metal Surface Beneath Amana Shelf 15.4 Painting The Cooking Cavity 15.5 How To Replace A Sealed-In Ceramic Shelf Shelves With A Preformed Gasket 15.6 Waveguide Disorders

9 15.7 Door Leakage and Safety System Checks and Failures RF Leakage Test Procedure 15.8 Door Adjustment General Door Alignment Steam and Light Escaping Around The Door 15.9 Classic Early Amana Doors Warping of the Frame Replacing the Inner Door General Door Disassembly Older Commercial Amana Doors Commercial Panasonic, Hobart, [new] Amana & Sharp Doors Post-Repair RF Leakage Check Chapter Sixteen Cooling and Energy Dispersion: Checks and Failures 16.1 Introduction 16.2 Symptoms of Blower System- Related Troubles 16.3 Blower Motor Test Operational Blower Motor Test An Alternate Test 16.4 Energy Distributions Systems Checks and Failures Microwave Heat Distribution Test Verifying Stirrer Or Antenna Rotation 16.5 Stirrer Or Antenna Maintenance Air-Driven 16.6 Stirrer Or Antenna Maintenance Motor-Driven An Operational Check An Alternate Test Stirrer Or Antenna Motor Replacement Considerations 16.7 Rotation Systems Checks and Failures 16.8 Stirrer and Waveguide Covers, Grease and Splatter Shields 16.9 Interrelated Failures Part 5 Troubleshooting By Symptom, Make, and Model Chapter Seventeen The Art of Common Sense Troubleshooting 17.1 Introduction 17.2 Practical Wisdom In Troubleshooting Sample Troubles A Final Note On Troubleshooting 17.3 Guilt By Association Chapter Eighteen Troubleshooting Commercial Models Service Codes and Procedures 18.1 Repairing Commercial Microwave Ovens Is... Not For Dummies 18.2 Commercial Models and Domestic Models What is the Difference? 18.3 Voltage Selection 18.4 Navigating a Commercial Kitchen Without Becoming a Loose Cannon Restaurant Rush Hours When and How to Make Service Calls 18.5 COMMERCIAL MICROWAVE OVENS DESCRIPTION OF OPERATION 18.6 TROUBLESHOOTING COMMERCIAL MICROWAVE OVENS Promptly Devise a Strategy Verifying Symptoms & Making a Preliminary Diagnosis How to remove a sealed-in shelf (tray) Undertaking On-Site Repairs Safely Troubleshooting Multiple-Magnetron Systems 18.7 SERVICE PROCEDURES AND FAILURE CODES Appendix I Touch Panel Test and Reference Matrix Diagrams Appendix II Microwave Cooking Techniques Appendix III Glossary Appendix IV Manufacturers & Parts Suppliers Contact Info Appendix V Repair Case History Database Symptoms and Solutions Appendix VI Magnetron Cross-Reference and Replacement Guide