Basic Information This Manual has been prepared to provide Electrolux Service Personnel with Operation and Service Information for Electrolux Microwave Ovens EI27MO45GSA and EI30MO45GSA. Table of Contents Section 1 Basic Information Section 3 Troubleshooting and Testing Safe Servicing Practices ..........
Page 5
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. ELECTROLUX HOME PRODUCTS CANNOT BE RESPONSIBLE, NOR ASSUME ANY LIABILITY, FOR INJURY OR DAMAGE OF ANY KIND ARISING FROM THE USE OF THIS MANUAL.
Before servicing an operative unit, perform a microwave emission check as per the Microwave Measurement Procedure outlined in this service manual. If microwave emissions level is in excess of the specified limit, contact ELECTROLUX HOME PRODUCTS, INC. immediately. If the unit operates with the door open, service person should: 1) Tell the user not to operate the oven.
Basic Information 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. INVERTER UNIT, THAT INCLUDES HIGH VOLTAGE CAPACITOR, HIGH VOLTAGE POWER TRANSFORMER, HIGH VOLTAGE RECTIFIER, HEAT SINK ETC., AND MAGNETRON, HIGH VOLTAGE HARNESS ETC..
Basic Information Microwave Measurement Procedure (USA) A. Requirements: 1) Microwave leakage limit (Power density limit): The power density of microwave radiation emitted by a microwave oven should not exceed 1 mW/cm 2 at any point 5 cm or more from the external surface of the oven, measured prior to acquisition by a purchaser, and thereafter (through the useful life of the oven), 5 mW/cm 2 at any point 5 cm or more from the external surface of the oven.
Basic Information Microwave Measurement Procedure (Canada) After adjustment of the door switches are completed individually or collectively, switch test and microwave leakage test must be performed with survey instrument and test result must be confirmed to meet the requirement of the performance standard for microwave ovens as under mentioned.
Basic Information Grounding Instructions 3-Pronged Plug Grounded Receptacle Box This oven is equipped with a three prong grounding plug. It must be plugged into a wall receptacle that is properly installed and grounded in accordance with the National Electrical Code, local codes and ordinances. In the event of an electrical short circuit, grounding reduces the risk of Grounding Pin electric shock by providing an escape wire for the electric...
Basic Information Oven Diagram Touch Control Panel 1. One touch door open button. Push to open door. 2. Door latches. The oven will not operate unless the door is securely closed. 3. Removable turntable support. 4. Removable turntable. The turntable will rotate clock wise or counterclockwise.
Operation 6. When the door is opened during a cook cycle, the Operating Sequence Description monitor switch, door sensing switch, third door The following is a description of component functions switch, primary switch relay (RY1) and secondary during oven operation. interlock relay are activated with the following results.
Page 14
Operation SCHEMATIC NOTE: "*" indicates components with potential above 250V. NOTE: Condition Of Oven 1. Door Closed 2. Clock Appears On Display PRIMARY THIRD INTERLOCK DOOR CAVITY TEMP SWITCH C/T FUSE SWITCH FUSE N.O. COM. N.O. OVEN TURNTABLE LAMP MOTOR MOTOR POWER TRANSFORMER DOOR...
Operation Variable Cooking 2. Heat Potatoes. Moisture and humidity is emitted rapidly. You can smell the aroma as it cooks. When Variable Cooking Power is programmed, 120 volts AC is supplied to the power transformer intermittently through the contacts of relay (RY-2) and is operated by the control unit within a 32 second time base.
Operation Touch Control Panel Assembly Component Descriptions The touch control section consists of the following units. DOOR OPEN MECHANISM 1. Key Unit The door is opened by pushing the open button on the 2. Control Unit (Consists of Power Unit and LSI Unit). control panel, refer to the Figure D-1.
Operation MONITOR SWITCH TURNTABLE MOTOR The turntable motor rotates the turntable located on the The monitor switch is activated (the contacts opened) bottom of the oven cavity, so that foods on the turntable by the latch head on the door while the door is closed. cook evenly during cooking.
Operation Humidity Sensor Circuit (3) Detector Circuit of Absolute Humidity Sensor Circuit: This detector circuit is used to detect the output (1) Structure of Absolute Humidity Sensor: voltage of the absolute humidity circuit to allow the The absolute humidity sensor includes two LSI to control sensor cooking of the unit.
Troubleshooting and Testing Troubleshooting Guide When troubleshooting the microwave oven, it is helpful to follow the Sequence of Operation in performing the checks. Many of the possible causes of trouble will require that a specific test be performed. These tests are given a procedure letter which will be found in the “Test Procedure “section.
Page 20
Troubleshooting and Testing CK = Check / RE = Replace RE RE A B C D E E F F G H RE RE CK I CK CK CK J K L M N TEST PROCEDURE PROBLEM CONDITION Home fuse or circuit breaker blows when power cord is plugged into wall receptacle C/T fuse blows when power cord is...
Troubleshooting and Testing Test Procedures Procedure Component Test Letter MAGNETRON ASSEMBLY TEST HIGH VOLTAGES ARE PRESENT DURING THE COOK CYCLE, SO EXTREME CAUTION SHOULD BE OBSERVED. DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPONENTS OR WIRING. 1. Disconnect the power supply cord, and then remove outer case. 2.
Page 22
Troubleshooting and Testing Procedure Component Test Letter POWER TRANSFORMER TEST DO NOT TOUCH THE COMPONENTS OF THE POWER TRANSFORMER WHILE POWER TRANSFORMER IS ENERGIZED. IT IS DANGEROUS BECAUSE THIS HAS HIGH VOLTAGE COMPONENTS. (HIGH VOLTAGES ARE PRESENT AT THE HIGH VOLTAGE TERMINAL, SO DO NOT ATTEMPT TO MEASURE THE FILAMENT AND HIGH VOLTAGE.) 1.
Page 23
Troubleshooting and Testing Procedure Component Test Letter HIGH VOLTAGE CAPACITOR TEST 1. Disconnect the power supply cord, and then remove outer case. 2. Open the door and block it open. 3. Discharge high voltage capacitor. (See Warnings and Instructions on page 3-1) 4.
Page 24
Troubleshooting and Testing Procedure Component Test Letter 5. If the C/T fuse is blown when the door is opened, check the secondary interlock relay, primary interlock switch and monitor switch according to the “TEST PROCEDURE” for those switches before replacing the blown monitor fuse. Before replacing a blown CT fuse, test the secondary interlock relay, primary interlock switch, door sensing switch and monitor switch for proper operation.
Page 25
Troubleshooting and Testing Procedure Component Test Letter SECONDARY INTERLOCK RELAY (RY2) 1. Disconnect the power supply cord, and then remove outer case. 2. Open the door and block it open. 3. Discharge high voltage capacitor. 4. Disconnect two (2) wire leads from the male tab terminals of the Secondary Interlock Relay. Check the state of the relay contacts using a ohmmeter.
Page 26
Troubleshooting and Testing Procedure Component Test Letter TOUCH CONTROL PANEL ASSEMBLY TEST The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore, unlike conventional microwave ovens, proper maintenance cannot be performed with only a voltmeter and ohmmeter. In this service manual, the touch control panel assembly is divided into two units, Control Unit and Key Unit, and also the Control Unit is divided into two units, LSI Unit and Power Unit, and troubleshooting by unit replacement is described according to the symptoms indicated.
Page 27
Troubleshooting and Testing Procedure Component Test Letter 2. Control Unit The following symptoms indicate a defective control unit. Before replacing the control unit, perform the Key unit test (Procedure J) to determine if control unit is faulty. 2-1 In connection with pads. 1.
Page 28
Troubleshooting and Testing Procedure Component Test Letter Key Unit Test NO. G1 NO. G13 Key unit ribbon cable Key unit (Membrane Switch) front view RELAY TEST 1. Disconnect the power supply cord, and then remove outer case. 2. Open the door and block it open. 3.
Page 29
Troubleshooting and Testing Procedure Component Test Letter DEFROST TEST WARNING : The oven should be fully assembled before following procedure. 1. Place one cup of water in the center of the turntable tray in the oven cavity. 2. Close the door. 3.
Page 30
Troubleshooting and Testing Pin# Signal Description Power source voltage : -5.0 Volts. The power source voltage to the drive LSI is input to VSS terminal. Internal clock oscillation frequency control input setting. The internal clock frequency is set by inserting the ceramic filter oscillation circuit with re- spect to XOUT terminal.
Page 31
Troubleshooting and Testing Pin# Signal Description Signal to Buzzer: Duration Signal to sound buzzer: PWM Buzzer “Lingering”: PWM still “ON” while Duration is “OFF” Duration Signal coming from touch key. When G1 line on key matrix is touched, a corresponding signal out of P80-P87 is input into P53.
Component Teardown TO PREVENT AN ELECTRIC SHOCK, TAKE THE FOLLOWING PRECAUTIONS: 1. BEFORE WIRING: 1) Disconnect the power supply. 2) Open the door and wedge the door open. 3) Discharge the high voltage capacitor and wait for 60 seconds. 2. DO NOT LET WIRE LEADS TOUCH TO THE FOLLOWING PARTS: 1) High voltage parts: Magnetron, High voltage transformer, High voltage capacitor and High voltage rectifier assembly.
Component Teardown Outer Case Removal Power Transformer Removal Removal 1. Disconnect the oven power supply cord and remove outer case. 1. Disconnect oven from power supply before 2. Open the oven door and block it open. removing outer case. 3. Discharge high voltage capacitor. 2.
Component Teardown High Voltage Rectifier and High Magnetron Removal Voltage Capacitor Removal Removal 1. Disconnect the power supply cord and then remove 1. Disconnect the power supply cord and then remove outer case. outer case. 2. Open the door and block it open. 2.
Component Teardown ® Oven Lamp and Lamp Socket Positive Lock Connector (No-Case Removal Type) Removal 1. Disconnect oven from power supply and remove 1. Disconnect oven from power supply and remove outer case. outer case. 2. Open the door and block it open. 2.
Component Teardown Fan Motor Removal Installation Install the fan blade to the fan motor shaft according to Removal the following procedure: 1. Disconnect the oven power supply cord and remove 1. Hold the center of the bracket which supports the outer case.
Component Teardown Servicing The Touch Control Panel while keeping it connected to the oven. b) On some models, the power supply cord between Precautions For Handling Electronic Components the touch control panel and the oven proper is long This unit uses CMOS LSI in the integral part of the enough that they may be separated from each other.
Component Teardown Installation Control Panel Assembly Removal 1. Remove remaining adhesive on the control panel 1. Disconnect the oven power supply cord and remove frame surfaces with a soft cloth soaked in alcohol. outer case. 2. Make sure that the VFD (Vacuum Fluorescent 2.
Component Teardown Door Sensing Switch/Primary Switch/ Door Sensing Switch/Primary Switch/ Third Door Switch And Monitor Switch Third Door Switch And Monitor Adjustment Switch Removal 1. Disconnect the power supply cord, and then remove Removal outer case. 1. Disconnect the oven power supply cord and remove 2.
Component Teardown After adjustment, check the following. Door Replacement 1. In and out play of door remains less than 0.5mm 1. Disconnect the power supply cord. when in the latched position. First check upper 2. Push the open button and open the door slightly. position of latch hook, pushing and pulling upper 3.
Component Teardown Re-Install 1. Re-install door screen to door frame. The door on a microwave oven is designed to act 2. Re-install the latch spring to the latch head. Re-install as an electronic seal preventing the leakage of the latch spring to the door frame. Re-install latch microwave energy from the oven cavity during the head to door frame.
Page 47
Parts List NOTE: The parts marked “ ” may cause undue microwave exposure. The parts marked “*” are used in voltage more than 250V. DESCRIPTION REF. NO. Q’TY ELECTRICAL PARTS High voltage assembly Lamp socket Oven lamp Fan motor Monitor switch (V-16G-2C25), C/T fuse (20A 250V AC) & Inst. Primary interlock switch and door sensing switch (V-5230Q) Cavity temperature fuse 150ºC Magnetron...
Page 48
Parts List DESCRIPTION REF. NO. Q’TY ELECTRICAL PARTS Main wire harness Turntable support Turntable tray Monitor caution label DHHS/Screw caution label Operation manual High voltage wire A NHW caution label SCREWS, NUTS AND WASHERS Special screw Special screw Screw : 4mm x 12mm Screw : 4mm x 12mm Screw : 3mm x 8mm Screw : 4mm x 8mm...
Page 50
Parts List Control And Door Parts Actual wire harness may be different from illustration.
Page 51
Parts List Packing and Accessories TOP PAD ASSEMBLY DOOR PROTECTION SHEET 47 TURNTABLE TRAY PLASTIC BAG On Top Of Oven TRAY HOLDER OPERATION MANUAL BOTTOM PAD ASSEMBLY 46 TURNTABLE SUPPORT PACKING CASE Non-replaceable items.