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website http://www.lgservice.com
MICROWAVE OVEN
SERVICE MANUAL
MODEL: LMV1825SB
LMV1825SW
LMV1825SBQ
CAUTION
BEFORE SERVICING THE UNIT, READ THE
SAFETY PRECAUTIONS IN THIS MANUAL.
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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; (1) Interlock operation, (2) proper door closing, (3) seal and sealing surfaces (arcing, wear, and other damage), (4) damage to or loose
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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.....................................................................................................................
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SPECIFICATIONS Rated Power Consumption..................................................1,500W maximum (Microwave oven+Cook top lamps+Ventilation fan) Microwave Output.................................................................1000W (IEC 60705) Adjustable 100W through 1000W, 10 steps Frequency.............................................................................2,450 MHz 50 MHz Power Supply........................................................................120 VAC, 60 Hz Rated Cu
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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. • DO NOT operate on a 2-wire extension cord during All input and output microwave connections, repair and use. waveguide,
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INSTALLATION 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. C. Install the unit on the mounting plate firmly. D. Place the unit as far away as possible from TV, radio, etc. to prevent interference. GROUNDING INSTRUCTIONS For personal safety,
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OPERATING INSTRUCTIONS CONTROL PANEL 1 4 2 3 5 7 6 9 8 10 11 13 12 14 16 15 17 19 18 22 20 21 25 23 24 4-1
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CONTROL PANEL INSTRUCTIONS 1. DISPLAY: The Display includes a clock and indicators to 14. STOP/CLEAR: Touch this pad to stop the oven or to tell you time of day, cooking time settings and cooking clear all entries. functions selected. 15. CLOCK: Touch this pad to enter the time of day. 2. MORE: Touch this pad to add ten seconds of cooking 16. START: Touch this pad to start a function. If you open time each time you press it. the door after oven begins to cook, START again. 3. LESS: Touch this
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OVERALL CIRCUIT DIAGRAM SCHEMATIC DIAGRAM 5-1
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MATRIX CIRCUIT FOR TOUCH KEY BOARD 2 1 3 5 4 6 7 VENT TIME N.C N.C N.C 5 0 HI/LO/OFF COOK 8 CUSTOM AUTO LIGHT N.C N.C 6 1 HI/LO/OFF SET DEFROST 9 KITCHEN LESS CLOCK Ez-On N.C 7 2 TIMER 10 LIGHT CUSTOM POWER N.C N.C 8 3 TIMER COOK LEVEL 11 TURNTABLE STOP HOLD START N.C 9 4 WARM ON/OFF CLEAR 12 SENSOR SENSOR SENSOR SENSOR SENSOR SENSOR MORE PIZZA POTATO POPCORN VEGETABLE VEGETABLE REHEAT COOK 13 5-2
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GENERAL INFORMATION FOR SERVICE FEATURES AND SPECIFICATIONS GENERAL PRECAUTIONS IN USE 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 be sure to put a glass of water into the cooking (3) Interlock monitor switch compartment.
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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. CARRIED OUT WITH GREAT CARE. (a) The door does not close firmly. The filament leads of magnetron carry High (b) The hinge is broken. Voltage with respect to ground. Extreme caution (c) The door seal is damaged
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MICROWAVE LEAKAGE TEST MEASURING MICROWAVE ENERGY CAUTIONS 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 • The service personnel should inform the on the center of the turntable. manufacture importer, or assembler of any certified • Set the energy leakage monitor to 2,450 MHz and oven unit found to have a microwave emission
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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. is installed and after all necessary components (3) The test probe must be held by the grip portion of are replaced or adjusted. Special care should be the hand
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DISASSEMBLY INSTRUCTIONS (4) Remove 3 screws securing the circuit board. IMPORTANT NOTES: 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. THE CAPACITOR SHOULD BE DISCHARGED BY USING INSULATED WIRE - I.E. TEST PROBE CONNECTED TO 10K-OHM RESISTOR IN SERIES TO GROUND. WHEN RECONNECTING THE WIRE LEADS TO ANY
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HOW TO INSERT THE F.P.C. CONNECTOR HOW TO REMOVE THE F.P.C. CONNECTOR Follow the steps below as illustrated in Figures 6 Follow the steps below as illustrated in Figures 4 and 7 to insert the F.P.C. connector. and 5 to remove the F.P.C. connector. (1) Insert the F.P.C. connector into the terminal socket securely with the fingers. (1) Hold the edges of the plastic fastener with (2) Hold the plastic fastener with thumb and thumb and forefinger. forefinger of the other hand, and push it (Fig
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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. (4) Remove two screws on the left central edge and one screws on the right central edge of Base plate. Remove the Mount, All from the out case by removing one screw securing it to the out case. (5) Remove the outcase with disconnecting p
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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 Latch Board Secondary Interlock Switch WH(from H.V.Transformer) YL(from Fan Motor) WH(from Power Cord) WH(from cooktop lamp) Interlock Monitor Switch Primary Interlock Switc
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NOTES: D. REMOVING MAGNETRON • 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) • When replacing the magnetron, be sure to install the (2) Remove the outcase. See page 7-6. magnetron gasket in the correct position and be sure (3) Remove three tap tite screws securing the that the gasket is in good condition. magnetron to the wave guide. • After repla
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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. (2) Rotate slightly and pull out the stirrer fan cover. (3) Remove the stirrer fan. NOTES: • After replacing the door, be sure to check that the primary interlock switch, the secondary interlock switch and the interlock monitor sw
