LG MC2841SPS Service Manual
  1. Manuals
  2. Brands
  3. LG Manuals
  4. Microwave Oven
  5. MC2841SPS
  6. Service manual

LG MC2841SPS Service Manual

Hide thumbs
Table of Contents

Advertisement

Quick Links

Download this manual
MODEL: MC2841SPS

Advertisement

Table of Contents
loading

Related Manuals for LG MC2841SPS

Summary of Contents for LG MC2841SPS

  • Page 1 MODEL: MC2841SPS...

  • 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 MC2841SPS Power Requirement 230 Volts AC 50 Hz Single phase, 3 wire grounded Microwave 1350W Grill 1100W Convection 750W(Max.1900W) Combination 3100W Power Output 900 Watts full microwave power (IEC60705) Microwave Frequency 2450 MHz ± 50 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. 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 Multi Cook Tawa Safety Door Lock System Turntable Rotating Ring High Rack Low Rack CONTROL PANEL 1. DISPLAY WINDOW: Used to show time of day, cooking of veg, power level of cooking, cooking category.

  • Page 8: Operating Sequence

    OPERATING SEQUENCE The following is a description of component functions during oven operation. 6. AUTO COOK 1. MICROWAVE COOKING Stop/ Function Desired Auto Select Desired Press Stop/Clear Clear Auto Cook Cook category Micro power level Dial Press Food Desired Start Start Dial weight...

  • Page 9: Schematic Diagram

    SCHEMATIC DIAGRAM...

  • Page 10: Circuit Description

    CIRCUIT DESCRIPTION GENERAL DETAILS WHEN THE DOOR IS OPENED DURING COOKING • The low voltage transformer supplies the necessary voltage to the micom controller when power cord is • Both the primary switch and relay 2 are cut off primary winding voltage of the high voltage transformer.

  • 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 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 4187 x (∆T) + 0.55 X (T )X M...
  • Page 14 F. AIR DUCT ASSEMBLY REMOVAL 1) Disconnect the leadwire from lamp. 2) Remove the mounting screw to the cavity. G. MAGNETRON REMOVAL 1) Disconnect the leadwire from the high voltage transformer and high voltage capacitor. 2) Carefully remove the mounting screws holding the magnetron and the waveguide.
  • Page 15 H. FAN MOTOR ASSEMBLY REMOVAL K. THE TURNTABLE MOTOR REMOVAL 1) Discharge the high voltage capacitor. 1) Remove the turntable. 2) Disconnect the leadwire from fan motor, noise filter 2) Remove the turntable shaft VERY CAREFULLY and high voltage capacitor. with a slotted screwdriver.
  • Page 16 L. C-MOTOR AND SHEATH HEATER M. INTERLOCK SYSTEM REMOVAL 1) INTERLOCK MECHANISM The door lock mechanism is a device which has 1) Remove the air guide and the air duct. been specially designed to eliminate completely 2) Disconnect the leadwire from the circulation motor microwave activity when the door is opened during and the sheath heater.

  • 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 OR V-5230Q FOR PRIMARY SWITCH TYPE NO. SZM-V 16-FA-62 OR VP-532A-OF OR V-5220Q FOR MONITOR SWITCH TYPE NO.

  • 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 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 9 pin Check for P.C.B. connector. connector from P.C.B. (Refer to schemetic diagram) 1 2 3 4 5 6 7 8 9 Cooking Start RELAY 2, RELAY 3, RELAY 5 OF P.C.B. (Wire leads removed.) Relay 2 Relay 2: Microwave...
  • Page 22 COMPONENTS TEST PROCEDURE RESULTS CIRCULATION MOTOR Normal : COM-230V : Approx. 160 Ω (Wire leads removed) Abnormal : Infinite or several ohm. NOTE : A MICROWAVE ENERGY LEAKAGE TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS SERVICED FOR ANY REASON. MAKE SURE THE WIRE LEADS ARE CORRECT POSITION.

  • Page 23: Trouble Shooting (Display Shows Error Mode)

    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 24 (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 25 (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 Replace Defective Malfunction of the Check continuity 1. Fuse blows. Continuity. monitor switch. switches. of monitor switch (with door closed).
  • Page 26 (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 27 (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. oscillation. wire leads from assembly assembly relay 2 and check continuity Continuity.
  • Page 28 (TROUBLE 6) Oven does not cook properly when programmed for the set power level (Operates properly on HIGH) CONDITION CHECK RESULT CAUSE REMEDY Output is full when Defective P.C.B. Replace P.C.B. Disconnect the Abnormal. you set lower assembly. assembly. wire leads from power level.
  • Page 29 (TROUBLE 8) Display shows error mode CONDITION CHECK RESULT CAUSE REMEDY Display shows Connect them Check the No continuity Loose connection "F02" tightly connnection between thermistor and Continuity P.C.B. assembly Check the Defective thermistor Replace the Abnormal. thermistor (Thermistor shorted) thermistor Defective Replace the...

  • Page 30: Exploded View

    EXPLODED VIEW INTRODUCTION OVEN CAVITY PARTS INTERIOR PARTS BASE PLATE PARTS LATCH BOARD PARTS CONTROL PANEL PARTS -6-1-...
  • Page 31 DOOR P ARTS 13581A -6-2-...
  • Page 32 CONTROL PANEL PARTS 268711 23572A 23506A -6-3-...
  • Page 33 OVEN CAVITY PARTS 33112U 372901 35300A 33052M 33390M 33390G 33390H 34370T 33390L 35889A 36549S -6-4-...
  • Page 34 LATCH BOARD PARTS 33052N 43500A 466001 466003 466001 -6-5-...
  • Page 35 INTERIOR PARTS 56411C 56892 56322A 535042 36549U 56411A 535041 365901 56411B 35300B 56930A 56411D 365501 50FZZA 56201A 34810H 36549T 56912B 55900A 54974S 56930G 56851D 50CZZH 56324A -6-6-...
  • Page 36 BASE PLATE PARTS 56170D -6-7-...
  • Page 38 SVC PART LIST S.no. Location Part No. Description Level SVC Code Quantity 33052N ABU73033219 Cavity Assembly,welding 36549S 2B72754F Motor, AC Synchronous 56411B EAD60848707 Harness,Multi 535041 MBR61841701 Chamber 535042 MBR61841602 Chamber 36549u EAU61783001 Motor,AC 365901 MDG30365901 Fan,Stirrer 365501 MDG30365501 Fan,Stirrer 56411D 6877W1A424L Harness,Single 56411D...

Table of Contents