Related Manuals for LG MH2044DB
Summary of Contents for LG MH2044DB
- Page 1 Website http://biz.lgservice.com MICROWAVE OVEN SERVICE MANUAL MODEL: MH2044DB CAUTION BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
-
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 Model MH2044 Power Requirement 230 Volts AC 50 Hz Single phase, 3 wire grounded Grill 980W Combination 2100W Power Output 700 Watts full microwave power (IEC60705) Microwave Frequency 2450 MHz Magnetron 2M246 Timer 0 ~ 99:99 min. Outside Dimensions 455 (W) x 260 (H) x 340 (D) mm Cavity Dimensions... -
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 Front Plate Window Door Screen Door Seal Control Panel Safety Door Lock System Turntable Roller Rest Grill rack CONTROL PANEL 1. MICRO: Used to select micro cooking. 2. GRILL: Used to select grill cooking. 3. COMBI: Used to select Combi cooking. 4. -
Page 8: Operating Sequence
OPERATING SEQUENCE The following is a description of component functions during oven operation. 1. SETTING THE CLOCK 7. MULTI-STAGE MICROWAVE COOKING STOP/ 1ST STAGE CLOCK NUMBER CLOCK CLEAR STOP/ POWER TIME START CLEAR NOTE: 1) This is a 24 hour clock. 2) Clock will operate as long as power is applied to the oven. - Page 9 MGT THERMAL GRILL...
-
Page 10: Circuit Description
CIRCUIT DESCRIPTION power of microwave oven as POWER LEVEL. GENERAL DETAILS (refer to page 1-1) • The low voltage transformer supplies the necessary voltage to the micom controller when power cord is WHEN THE DOOR IS OPENED DURING plugged in. COOKING •... -
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) • Microwave survey meter Standard tools are listed below. - Holaday HI-1500 • Diagonal pliers HI-1501 •... - Page 12 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 • The microwave power output P in watts is calculated • Microwave power output measurement is made with the microwave oven supplied at its rated voltage and from the following formula : operated at its maximum microwave power setting with 4187 X (∆T) + 0.55 X (T ) X M a load of (1000±5) g of potable water. - Page 14 D. DOOR GROSS ASSEMBLY REMOVAL E. HIGH VOLTAGE TRANSFORMER REMOVAL 1) Open the door. 2) Pull out the door protector very carefully with a flat- 1) Discharge the high voltage capacitor. blade 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) Disconnect the leadwire from lamp, A.C Relay and 1) Remove the turntable. monitor resistor and magnetron. 2) Remove the turntable shaft VERY CAREFULLY. 2) Remove the screw to the magnetron cavity. 3) Lay the unit down on its back.
- 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 MEASUREMENT OF MICROWAVE POWER OUTPUT WARNING : FOR CONTINUED PROTECTION AGAINST EXCESSIVE RADIATION EMISSION, REPLACE ONLY WITH IDENTICAL REPLACEMENT PARTS. ALL THESE SWITCHES MUST BE REPLACED AT THE SAME TIME. 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 A.
-
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 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) several ohms, and then...
- Page 20 COMPONENTS TEST PROCEDURE RESULTS FUSE Check for continuity of the fuse with an Normal Abnormal multi-meter. NOTE: If the fuse is blown, check the primary, the secondary, and the monitor switches, H.V.D. and H.V.C. before replacing the fuse. If the fuse is blown by improper switch operation replace the defective switch and the fuse at the same time.
- Page 21 COMPONENTS TEST PROCEDURE RESULTS Cooking Start Disconnect the 8 pin Check for P.C.B.connector. connector from P.C.B. (Refer to schemetic diagram) Cooking Start RELAY 2, RELAY 3 OF P.C.B. Relay 3 (Wire leads removed.) Note: Relay Relay 1 Relay 1: Fan motor Turntable motor Oven lamp Relay 2: Microwave...
-
Page 22: 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 23 (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 24 (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 Check continuity Replace defective 1. Fuse blows. Continuity. monitor switch. of monitor switch switch (with door closed).
- Page 25 (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 does No continuity. secondary switch. secondary switch.
- Page 26 (TROUBLE 5) No microwave oscillation even though oven lamp and fan motor run (Display operates properly) CONDITION CHECK RESULT CAUSE REMEDY No microwave Disconnect the Defective P.C.B Replace P.C.B No continuity. assembly oscillation. wire leads from assembly relay 2 and check continuity Continuity.
- Page 27 (TROUBLE 7) Oven does not cook properly when programmed for the set power level (Operates properly on HIGH) CONDITION CHECK RESULT CAUSE REMEDY Defective P.C.B. Replace P.C.B. Output is full when Disconnect the Abnormal. assembly. assembly. you set lower wire leads from power level.
-
Page 28: Exploded View
#EV# EXPLODED VIEW INTRODUCTION OVEN CAVITY PARTS INTERIOR PARTS BASE PLATE PARTS DOOR PARTS LATCH BOARD PARTS CONTROL PANEL PARTS... - Page 29 #EV# DOOR PARTS 13581A...
- Page 30 #EV# CONTROLLER PARTS 24781M...
- Page 31 33390B 33112U 44360A 33052M 35300A 35026G 33390G 35889A 36549S...
- Page 32 #EV# LATCH BOARD PARTS 569128 43500A 466001 466003 466001...
- Page 33 #EV# INTERIOR PARTS 568771 56411A 56930G 56930V 34810J 50FZZA 56201A 56549F 55900A 54974A 56930M 56851D 50CZZH 56324A 34810H 92502G...
- Page 34 #EV# BASE PLATE PARTS 56170D...
-
Page 35: Replacement Parts List
REPLACEMENT PARTS LIST R: SERVICE PARTS...