Summary of the content on the page No. 1
website: http://www.lgservice.com
MICROWAVE OVEN
SERVICE MANUAL
MODEL : LMV1625B
LMV1625W
CAUTION
BEFORE SERVICING THE UNIT, READ THE
SAFETY PRECAUTIONS IN THIS MANUAL.
Summary of the content on the page No. 2
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
Summary of the content on the page No. 3
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........................................................................................................................
Summary of the content on the page No. 4
SPECIFICATIONS Rated Power Consumption .................................... 1,500W maximum (Microwave oven+Cook top lamp+Ventilation fan) Microwave Output .................................................. 1,000W (IEC 60705) Adjustable 100W through 1000W, 10 steps Frequency .............................................................. 2,450 MHz ± 50 MHz Power Supply......................................................... 120 VAC, 60 Hz Rated Current ..........................................
Summary of the content on the page No. 5
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,
Summary of the content on the page No. 6
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. 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,
Summary of the content on the page No. 7
OPERATING INSTRUCTIONS CONTROL PANEL 1 2 4 3 7 5 9 6 10 8 12 11 14 13 15 16 17 19 18 21 20 24 22 26 25 23 4-1
Summary of the content on the page No. 8
CONTROL PANEL INSTRUCTIONS 1. DISPLAY: The Display includes a clock and 14. CUSTOM SET: Touch this pad to change the indicators to tell you time of day, cooking time oven’s default settings for sound, clock, display settings and cooking functions selected. speed and defrost weight. 2. POPCORN: Touch this pad when popping popcorn 15. CLOCK: Touch this pad to enter the time of day. in your microwave oven. 16. HOLD WARM: Touch this pad to keep hot, cooked 3. PIZZA: Touch this pad to reheat 1 to 3
Summary of the content on the page No. 9
OVERALL CIRCUIT DIAGRAM SCHEMATIC DIAGRAM 5-1
Summary of the content on the page No. 10
MATRIX CIRCUIT FOR TOUCH KEY BOARD FAN TIME HELP COOK POPCORN HI/LO/OFF COOK LIGHT CUSTOM AUTO REHEAT POTATO HI/LO/OFF SET DEFROST KITCHEN LESS CLOCK Ez On BEVERAGE TIMER CUSTOM LIGHT POWER N.C PIZZA COOK TIMER LEVEL T/TABLE STOP HOLD START N.C ON/OFF CLEAR WARM MORE N.C N.C N.C N.C N.C N.C 5-2
Summary of the content on the page No. 11
GENERAL INFORMATION FOR SERVICE (1) Primary interlock switch GENERAL PRECAUTIONS IN USE (2) Secondary interlock switch A. Never operate the unit when it is empty. (3) Interlock monitor switch Operating the oven with no load may shorten the (4) Choke system life of the magnetron. Whenever cooking dry foods (5) Magnetron thermostat (dried fish, bread, etc.) or a small amount of food, (6) Oven cavity thermostat be sure to put a glass of water into the cooking (Note: This thermostat located on th
Summary of the content on the page No. 12
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.
Summary of the content on the page No. 13
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 • 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
Summary of the content on the page No. 14
MEASUREMENT WITH THE OUTER CASE NOTE WHEN MEASURING (1) Do not exceed meter full scale deflection. REMOVED (2) The test probe must be removed 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 are (3) The test probe must be held with the grip portion replaced or adjusted. Special care should be of the ha
Summary of the content on the page No. 15
DISASSEMBLY INSTRUCTIONS (4) Remove 2 screws securing the circuit board. IMPORTANT NOTES: UNIT MUST BE DISCONNECTED FROM ELECTRICAL 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 PART
Summary of the content on the page No. 16
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) Insert the F.P.C. connector into the terminal (1) Hold the edges of the plastic fastener socket securely with the fingers. withthumb and forefinger. (2) Hold the plastic fastener with thumb and (Figure 4) forefinger of the other hand, and push it
Summary of the content on the page No. 17
B. REMOVING THE OUT CASE(Figure 8) (6) Remove the power cord cover from outcase by (1) Remove the vent grille by removing two screws removing a screw. securing it to the out case. (7) Remove the power cord to the inner of the out (2) Remove two screws securing it to the front bracket. case with turning power cord and remove the out (3) Remove two screws securing it to the air duct. case with pushing it back. (4) Remove the mounting plate by turning the two screws securing it to the out case. (
Summary of the content on the page No. 18
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) WH(from Monitor S/W) WH(from Oven Thermostat) WH(from Cooktop lamp Interlock Monitor Switch Primary Interlock
Summary of the content on the page No. 19
D. REMOVING MAGNETRON NOTE: (Figures 11 Through 13) • When removing the magnetron, make sure that its dome does not hit any adjacent parts, or it may be (1) Remove vertgrille. damaged. (2) Remove mount all. • When replacing the magnetron, be sure to install the (3) Remove outcase. magnetron gasket in the correct position and be sure (4) Discinnect the wireleads. that the gasket is in good condition. (5) Remove the 3 screws and Magnetron very • After replacing the magnetron, check for microwave c
Summary of the content on the page No. 20
F. REMOVING DOOR (Figure 14) (1) Remove the vent grille by two screws securing it to the outcase loosening. (2) Lift up and draw the door. NOTES: • After replacing the door, be sure to check that the primary interlock switch, the secondary interlock switch and the interlock monitor switch is in good operating normally. • After replacing the door, check for microwave energy leakage with a survey meter. Microwave energy 2 leakage must be below the limit of 5mW/cm (With a 275 ml water load) Figure
