LG LMVM1935SB Service Manual
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- Owner's manual & cooking manual (36 pages) ,
- Installation instructions manual (20 pages)
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Summary of Contents for LG LMVM1935SB
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Page 1: Microwave Oven
MICROWAVE OVEN SERVICE MANUAL MODEL: LMVM1935SB LMVM1935SW LMVM1935SBQ LMVM1935T \CAUTION BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL. June, 2005 P/NO : 3828W5S4601 Printed in Korea... -
Page 2: Safety Precautions
CAUTION SAFETY PRECAUTIONS PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY a. Do not operate or allow the oven to be operated with the door open. b. Make the following safety checks on all ovens to be serviced before activating the magnetron or other microwave source, and make repairs as necessary;... -
Page 3: Table Of Contents
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. TABLE OF CONTENTS (Page) SAFETY PRECAUTIONS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Inside front page SPECIFICATIONS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1-1 CAUTIONS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 2-1 INSTALLATIONS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 3-1... -
Page 4: Specifications
SPECIFICATIONS Rated Power Consumption - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1500W maximum (Microwave oven+Cook top lamps+Ventilation fan) Microwave Output - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1050W (IEC 60705) Adjustable 105W through 1050W, 10 steps Frequency - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 2450 MHz ±... -
Page 5: Cautions
CAUTIONS Unlike other appliances, the microwave oven is MICROWAVE RADIATION high-voltage and high-current equipment. Personnel should not be exposed to the Though it is free from danger in ordinary use, microwave energy which may radiate from the extreme care should be taken during repair. magnetron or other microwave generating device if it is improperly used or connection. -
Page 6: Installations
INSTALLATIONS BEFORE YOU BEGIN, READ THE FOLLOWING INSTRUCTIONS COMPLETELY AND CAREFULLY. PRECAUTIONS ON INSTALLATION A. Plug the power supply cord into a 120V AC, 60Hz, single-phase power source with a capacity of 15A or 20A. B. Avoid placing the unit in a location where there is direct heat or splashing water. -
Page 7: Operating Instructions
OPERATING INSTRUCTIONS CONTROL PANEL... -
Page 8: Control Panel Instructions
CONTROL PANEL INSTRUCTIONS 1. DISPLAY: The Display includes a clock and indicators to 15. CUSTOM SET: Touch this pad to change the oven’s tell you time of day, cooking time settings and cooking default settings for clock set, sound, display speed and functions selected. -
Page 9: Overall Circuit Diagram
OVERALL CIRCUIT DIAGRAM SCHEMATIC DIAGRAM (I) *Check the Model No. -
Page 10: Schematic Diagram (Ii)
SCHEMATIC DIAGRAM (II) *Check the Model No. (ADD Noise filter) -
Page 11: Matrix Circuit For Touch Key Board
MATRIX CIRCUIT FOR TOUCH KEY BOARD... -
Page 12: General Information For Service
GENERAL INFORMATION FOR SERVICE GENERAL PRECAUTIONS IN USE FEATURES AND SPECIFICATIONS FEATURES A. Never operate the unit when it is empty. Operating the oven with no load may shorten the A. The safety systems incorporated in this model are: life of the magnetron. Whenever cooking dry foods (1) Primary interlock switch (dried fish, bread, etc.) or a small amount of food, (2) Secondary interlock switch... -
Page 13: Service Information
SERVICE INFORMATION PRECAUTIONS AND REPAIR SERVICE TIPS PRELIMINARY (3) Do not operate the unit until it is completely A. SINCE NEARLY 2,100 VOLTS EXISTS IN SOME repaired, if any of the following conditions exist. CIRCUITS OF THIS UNIT REPAIRS SHOULD BE The unit must not be operated. -
Page 14: Microwave Leakage Test
MICROWAVE LEAKAGE TEST CAUTIONS MEASURING MICROWAVE ENERGY LEAKAGE • Be sure to check microwave leakage prior to servicing the oven if the oven is operative prior to • Pour 275±15cc of 20±5°C(68±9°F) water in a beaker servicing. which is graduated to 600 cc, and place the beaker •... -
Page 15: Measurement With The Outer Case Removed
MEASUREMENT WITH THE OUTER CASE NOTE WHEN MEASURING (1) Do not exceed meter full scale deflection. REMOVED (2) The test probe must be moved no faster than (1) When you replace the magnetron, measure for 1 inch/sec (2.5cm/sec) along the shaded area, microwave energy leakage before the outer case otherwise a false reading may result. -
Page 16: Disassembly Instructions
DISASSEMBLY INSTRUCTIONS IMPORTANT NOTES: (4) Remove 3 screws securing the circuit board. UNIT MUST BE DISCONNECTED FROM ELEC- TRICAL OUTLET WHEN MAKING REPAIRS, RE- PLACEMENTS, ADJUSTMENTS AND CONTIN-UITY CHECKS. WAIT AT LEAST ONE MINUTE, UNTIL THE HIGH VOLTAGE CAPACITOR IN THE HIGH VOLTAGE POWER SUPPLY HAS FULLY DISCHARGED. - Page 17 HOW TO REMOVE THE F.P.C. CONNECTOR HOW TO INSERT THE F.P.C. CONNECTOR Follow the steps below as illustrated in Figures 4 Follow the steps below as illustrated in Figures 6 and 5 to remove the F.P.C. connector. and 7 to insert the F.P.C. connector. (1) Hold the edges of the plastic fastener with (1) Insert the F.P.C.
- Page 18 B. REMOVING THE OUT CASE(Figure 8) (1) Remove the vent grille by removing two screws securing it to the out case. (2) Remove two screws securing it to the air duct. (3) Remove the mounting plate by turning the screws (1 or 2 screws) securing it to the out case.
- Page 19 C. REMOVING THE DOOR INTERLOCK SWITCHES (Figures 9,10) (1) Disconnect the wire leads from the interlock switches. (2) Remove two screws securing the Latch Board. (3) Make necessary replacements and check microwave energy leakage according to “ADJUSTMENT PROCEDURE” on page 7-12. Latch Board Secondary Interlock Switch...
- Page 20 D. REMOVING MAGNETRON NOTES: • When removing the magnetron, make sure that its (Figures 11 Through 13) dome does not hit any adjacent parts, or it may be (1) Remove the vent grille by loosening two screws. damaged. (Figure 11) •...
- Page 21 E. REMOVING STIRRER FAN F. REMOVING DOOR (Figure 16) (Figures 14 and 15) (1) Remove the vent grille by two screws securing it to (1) Remove one rivet ASS'Y securing it to the oven the outcase loosening. upper plate by using knife blade. (2) Lift up and draw the door.
- Page 22 H. ASSEMBLING DOOR (1) When mounting the door assembly to the oven (3) Carefully pull the ventilation motor ASS'Y out of the assembly, be sure to adjust the door assembly microwave oven. (See Figure 19-b) parallel to the chassis. Also adjust so the door has no play between the inner door surface and oven frame assembly.
- Page 23 K. REMOVING THE TURNTABLE MOTOR NOTES: • Remove the leadwire from the turntable motor (1) Remove the turntable. VERY CAREFULLY. (2) Remove the turntable shaft VERY CAREFULLY • Be sure to grasp the connector not the wires when with a slotted screwdriver. (Figure 20) removing.
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Page 24: Interlock System
INTERLOCK SYSTEM INTERLOCK MECHANISM The door 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 microwave leakage. ADJUSTMENT PROCEDURES To avoid possible exposure to microwave energy CHECK THE DOOR LATCH AND SWITCH leakage, adjust the door latches and interlock... - Page 25 TEST THE LATCH AND SWITCH SEQUENCE (5) Open the oven door slowly. Watch the door latch, (7) When you achieve the proper sequence of the Secondary Switch. Release Rod and Lever switches in Steps 5 and 6, tighten the latch board on the switches to make sure they are zero to the screws at that point.
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Page 26: Interlock Continuity Test
INTERLOCK CONTINUITY TEST A. PRIMARY INTERLOCK SWITCH TEST B. SECONDARY INTERLOCK SWITCH TEST When the door is opened slowly, an audible click Disconnect the wire lead from the secondary should be heard at the same time or successively switch. at intervals and the latches should activate the Connect the ohmmeter leads to the common switches with an audible click. -
Page 27: Test And Checkout Procedures And Trouble Shooting
TEST AND CHECKOUT PROCEDURES, AND TROUBLE SHOOTING - CAUTIONS - Secondary Winding - DISCONNECT THE POWER SUPPLY CORD FROM THE WALL OUTLET WHENEVER REMOVINGING THE CABINET FROM THE UNIT. PROCEED WITH THE TESTS ONLY AFTER DISCHARGING THE HIGH VOLTAGE CAPACITOR AND REMOVING THE WIRE LEADS FROM THE Filament PRIMARY WINDING OF THE HIGH VOLTAGE... - Page 28 COMPONENTS TEST PROCEDURES RESULTS Measure the resistance: (1) Terminal to terminal Normal reading: Momentarily indicates several ohms, and then gradually returns to infinite ohms. Abnormal reading: Ohm- Indicates continuity or infinite ohms meter from the beginning. Figure 25-a HIGH-VOLTAGE CAPACITOR (2) Terminal to case Normal readings: Infinite.
- Page 29 COMPONENTS TEST PROCEDURES RESULTS Measure the resistance between terminal When When not pins of connector KEY CONNECTOR. touched touched Resistance NOTE: value Less than More than When reconnecting the FPC connector, 400 ohms 1 mega ohm make sure that the holes on the FPC connector are properly engaged with hooks on the plastic fastener.
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Page 30: Checkout Procedures
COMPONENTS TEST PROCEDURES RESULTS POWER Check for continuity of relay 2 with an LEVEL ohm-meter. (Remove wire leads from relay 2 and 4 sec 18 sec operate the unit.) 6 sec 16 sec Relay 2 8 sec 14 sec 10 sec 12 sec 12 sec 10 sec... - Page 31 (2) CHECKOUT PROCEDURES FOR RELAY. - PROBLEM (A) - FAN motor and oven lamp turn on without touching START key when the door is closed. Remove the mate connector of I/O GOOD CON from the circuit board. Does the unit still operate? Replace the Defective circuit board...
- Page 32 (3) CHECKOUT PROCEDURES FOR CIRCUIT BOARD The following symptoms indicate a defective circuit 6) Wrong figures appear. board. 7) The figures of all digits. 1) The start function fails to operate but the high 8) Some of the indicators do no flicker light up. voltage Systems, the interlock switches, the door 9) The clock does not keep time properly.
- Page 33 7-21...
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Page 38: Exploded View
#EV# EXPLODED VIEW DOOR PARTS 1004 1002 1005 1000 1008 W136 1003 1007 1006 1011 W138 W142 1015 1012 -8-1-... - Page 39 #EV# CONTROLLER PARTS (I) 2006 2041 2042 2000 -8-2-...
- Page 40 #EV# CONTROLLER PARTS (II) 2004 W109 2009 2007 2008 2002 -8-3-...
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Page 41: Oven Cavity Parts
#EV# OVEN CAVITY PARTS W142 W108 3010 W138 3031 W109 W142 W138 3024 3029 3001 W121 6001 3014 3036 3032 5038 3018 W121 5036 6000 3028 3033 3026 W121 -8-4-... -
Page 42: Latch Board Parts
#EV# LATCH BOARD PARTS 4000 4001 4002 W111 4003 4002 4004 -8-5-... - Page 43 #EV# INTERIOR PARTS (I) 3002 5009 3012 W101 5002 W108 3008 5049 5000 5018 3034 W101 5008 W101 5058 W108 5024 5043 3009 5044 5019 5035 W105 W101 3004 -8-6-...
- Page 44 #EV# INTERIOR PARTS (II - II) Check the rating label of Model and order SVC parts according to the Model No. 3027 5045 W146 5015 5012 5038 5133 5022 W136 5006 5132 5032 W138 W101 5011 5010 5016 5001 W109 * Check the Rating Model No.
- Page 45 #EV# INSTALLATION PARTS 6011 6008 6010 6009 VINYL -8-9-...