Related Manuals for LG MS-74ML
Summary of Contents for LG MS-74ML
-
Page 1: Microwave Oven
MICROWAVE OVEN SERVICE MANUAL MODEL: MS-74ML CAUTION BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL. Jan, 2000 P/NO:3828W5S1403 Printed in Korea... -
Page 2: Safety Precautions
SAFETY PRECAUTIONS This device is to be serviced only by properly qualified service personnel. Consult the service manual for proper service procedures to assure continued safety operation and for precautions to be taken to avoid possible exposure to excessive microwave energy. PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY... -
Page 3: Table Of Contents
CONTENTS (Page) SAFETY PRECAUTIONS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Inside front cover SPECIFICATIONS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1-1 CAUTIONS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 2-1 INSTALLATIONS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 3-1... -
Page 4: Specifications
SPECIFICATIONS ITEM DESCRIPTION MS-74ML MODEL 120 V 60 Hz Power Requirement 1,050 Watts Single phase, 3 wire grounded Power Output 700 Watts full microwave power (IEC705) 2,450 MHz Microwave Frequency Magnetron 2M214 - 39F, 2M218J, 2M254J 0 ~ 99 min. 90 sec. -
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. INSTALLING EARTHING INSTRUCTIONS 1. Empty the microwave oven and clean inside it with This microwave oven is designed to be used in a fully a soft, damp cloth. Check for damage such as earthed condition. -
Page 7: Operating Instructions
OPERATING INSTRUCTIONS FEATURES Oven Frot Plate Window Door Screen Door Seal Display Window Control Panel Safety Door Lock System Turntable Rotating Ring CONTROL PANEL 1. INDICATORS 2. SET CLOCK: Used to set the time of day. 3. AUTO COOK: Used to cook the foods listed by one touch. -
Page 8: Operating Sequence
OPERATING SEQUENCE The following is a description of component functions 5. MULTI-STAGE MICROWAVE during oven operation. COOKING 1. SETTING THE CLOCK STAGE 1 Desired Desired Stop Set the power level cooking time Stop clock clock correct time STAGE 2 ex) To set 4:35, Press 10 min four times. Press 1 min three times. -
Page 9: Schematic Diagram
SCHEMATIC DIAGRAM... -
Page 10: Circuit Description
CIRCUIT DESCRIPTION • A high voltage of approximately 2100 volts AC is GENERAL DETAILS generated in the secondary of the high voltage • The low voltage transformer supplies the necessary transformer which is increased by the action of the high voltage to the micom controller when power cord is voltage diode and charging of the high voltage plugged in. -
Page 11: Service Information
SERVICE INFORMATION TOOLS AND MEASURING INSTRUMENTS NECESSARY TOOLS NECESSARY MEASURING INSTRUMENTS Tools normally used for TV servicing are sufficient. • TESTER(VOLTS-DC, AC., Ohmmeter) Standard tools are listed below. • Microwave survey meter • Diagonal pliers - Holaday HI-1500 • Long nose pliers HI-1501 •... -
Page 12: Record Keeping And Notification After Measurement
MEASUREMENT WITH OUTER CASE NOTES WHEN MEASURING REMOVED • Do not exceed meter full scale deflection. • The test probe must be removed no faster than • When you replace the magnetron, measure for 1 inch/sec (2.5 cm/sec) along the shaded area, microwave energy leakage before the outer case is otherwise a false reading may result. -
Page 13: Measurement Of Microwave Power Output
MEASUREMENT OF MICROWAVE POWER OUTPUT • Microwave power output measurement is made with • The microwave power output P in watts is calculated the microwave oven supplied at its rated voltage and from the following formula : operated at its maximum microwave power setting with 4187 x ( T) a load of (1000±5) g of potable water. -
Page 14: Diode Removal
D. DOOR GROSS ASSEMBLY REMOVAL E. HIGH VOLTAGE TRANSFORMER 1) Open the door. REMOVAL 2) Remove the choke cover very carefully with a flat-blade 1) Discharge the high voltage capacitor. screwdriver. 2) Disconnect the leadwire from magnetron, high voltage CAUTION : Be careful not to damage door seal plate transformer, and capacitor. - Page 15 H. AIR DUCT ASSEMBLY REMOVAL J. REMOVING THE TURNTABLE MOTOR 1) Remove the turntable. 1) Disconnect the leadwire from the lamp. 2) Remove the turntable shaft VERY CAREFULLY. 2) Remove the mounting screw to the latch board. 3) Lay the unit down on its back. 4) Remove the turntable motor cover.
- Page 16 K. PCB ASSEMBLY REMOVAL L. INTERLOCK SYSTEM 1) Remove the control panel assembly from the 1) INTERLOCK MECHANISM cavity. (Refer to control panel assembly removal The door lock mechanism is a device which has on previous page.) been specially designed to eliminate completely 2) Remove screws which hold the PCB SUB ASS’Y to microwave activity when the door is opened during the control panel.
-
Page 17: Interlock Continuity Test
INTERLOCK CONTINUITY TEST WARNING : FOR CONTINUED PROTECTION AGAINST EXCESSIVE RADIATION EMISSION, REPLACE ONLY WITH IDENTICAL REPLACEMENT PARTS. TYPE NO. SZM-V 16-FA-63 OR VP-533A-OF FOR PRIMARY SWITCH TYPE NO. SZM-V 16-FA-62 OR VP-532A-OF FOR MONITOR SWITCH TYPE NO. SZM-V 16-FA-63 OR VP-533A-OF FOR SECONDARY SWITCH B. -
Page 18: Component Test Procedure
COMPONENT TEST PROCEDURE CAUTIONS 1. DISCONNECT THE POWER SUPPLY CORD FROM THE OUTLET WHENEVER REMOVING THE OUTER CASE FROM THE UNIT. PROCEED WITH THE TEST ONLY AFTER DISCHARGING THE HIGH VOLTAGE CAPACITOR AND REMOVING THE WIRE LEADS FROM THE PRIMARY WINDING OF THE HIGH VOLTAGE TRANSFORMER. - Page 19 COMPONENTS TEST PROCEDURE RESULTS Antenna Gasket Chassis Filament Terminals NOTE: When testing the magnetron, be sure to install the magnetron gasket in the correct position and be sure that the gasket is in good condition. HIGH VOLTAGE Measure the resistance. Normal: Momentarily indicates CAPACITOR (Ohm-meter scale: Rx1000)
- Page 20 COMPONENTS TEST PROCEDURE RESULTS Check for continuity of relay 2 with an RELAY 2 POWER ohm-meter. LEVEL (Remove wire leads from relay 2 and operate the unit.) 6 sec 16 sec 10 sec 12 sec Relay 1 14 sec 8 sec Relay 2 18 sec 4 sec...
-
Page 21: Trouble Shooting
TROUBLE SHOOTING WHEN YOU GET A COMPLAINT FROM YOUR CUSTOMER, EVALUATE THE COMPLAINT CAREFULLY. IF THE FOLLOWING SYMPTOMS APPLY, PLEASE INSTRUCT THE CUSTOMER IN THE PROPER USE OF THE MICROWAVE OVEN. THIS CAN ELIMINATE AN UNNECESSARY SERVICE CALL. CAUTIONS 1. Check grounding before checking for trouble. 2. - Page 22 (TROUBLE 1) The following visual conditions indicate a probable defective control circuit. 1. Incomplete segments. • Segment missing. • Partial segment missing. • Digit flickering (NOTE:Slight flickering is normal.) 2. Colon does not turn on or blink. 3. A distinct change in the brightness of one or more numbers in display. 4.
- Page 23 (TROUBLE 2) Oven does not operate at all; Display window does not display any figures, and no input is accepted. CONDITION CHECK RESULT CAUSE REMEDY Malfunction of the Replace fuse, Check continuity 1. Fuse blows. Continuity. monitor switch. primary, monitor of monitor switches, and switch (with...
- Page 24 (TROUBLE 3) Display shows all figures set, but oven does not start cooking while desired program times are set and START pad is touched. CONDITION CHECK RESULT CAUSE REMEDY Defective Replace Check continuity 1. Setting time No continuity. secondary switch. secondary switch.
- Page 25 (TROUBLE 5) No microwave oscillation even though oven lamp and fan motor run. (Display operates properly) CONDITION CHECK RESULT CAUSE REMEDY No microwave Defective PCB Replace PCB Disconnect the No continuity. oscillation. assembly. assembly. wire leads from relay 2 and check continuity Continuity.
- Page 26 (TROUBLE 5) No microwave oscillation even though oven lamp and fan motor run. (Display operates properly) CONDITION CHECK RESULT CAUSE REMEDY Defective PCB Replace PCB Output is full power Disconnect the Abnormal. assembly. assembly. when you set lower wire leads from power level.
-
Page 27: Exploded View
#EV# EXPLODED VIEW INTRODUCTION MODEL : MS-74ML OVEN CAVITY PARTS INTERIOR PARTS BASE PLATE PARTS DOOR PARTS LATCH BOARD PARTS CONTROL PANEL PARTS... -
Page 28: Door Parts
#EV# DOOR PARTS 13581A 13536A 13552A 13213A 13720D 13352A 14026A 14970A... -
Page 29: Control Panel Parts
#EV# CONTROL PANEL PARTS 24781M 24930D 268711 23550D 23572A WTP018 26638A... -
Page 30: Oven Cavity Parts
#EV# OVEN CAVITY PARTS WTT021 33112U 33052M 33390G 36549S 35889A WTP013... -
Page 31: Latch Board Parts
#EV# LATCH BOARD PARTS 43501A 43500A WSZ085 466001 466003 466002 44510A... -
Page 32: Interior Parts
#EV# INTERIOR PARTS 568771 WSZ062 56411A 56930V WTT028 56549F WSZ002 54974S WTT037 55900A WSZ002 56912B 55262A 56324A WSZ002... -
Page 33: Base Plate Parts
#EV# BASE PLATE PARTS 56170D WSZ002 63302A 54810C 50CZZH 63303A 56851D WTT021 65006B WSZ002 65006B... -
Page 34: Schematic Diagram Of P.c.b
SCHEMATIC DIAGRAM OF P.C.B... -
Page 35: Printed Circuit Board
PRINTED CIRCUIT BOARD...