MICROWAVE OVEN SERVICE MANUAL
Contents
1. 5 8 TROUBLE SHOOTING Er 5 11 EXP ODE DIE We en En aa 6 1 REPLACEMENT PARTS LIST rar ee ernennen 7 1 SPECIFICATIONS MODEL MS 2344B MS 2544B Power Requirement 230 Volts AC 50 Hz Single phase 3 wire grounded Microwave 1250W Power Output 850 Watts full microwave power IEC 60705 Microwave Frequency 2450 MHz Magnetron 2M167B M47J1 Timer 0 99 Min Outside Dimensions 507 W x 283 H x 435 D mm Cavity Dimensions 331 W x 203 H x 360 D mm Net Weight 14 0 kg approx Shipping weight 16 0 kg approx Control Complement Microwave Power for Variable Cooking Power level Full power throughout the cooking time approx 80 of Full power MEDIUM approx 60 of Full power DEFROST approx 40 of Full power LOW WARM approx 20 of Full power Name plate Location Back Side Accessories Owner s manual Glass tray Rotating ring This microwave oven is designed for household use only It is not recommended for commercial purposes 1 1 CAUTIONS Unlike other appliances the microwave oven is high voltage and high current equipment Though it is free from danger in ordinary use extreme care should be taken during repair DO NOT operate on 2 wire extension cord during repair and use NEVER TOUCH any oven components or wiring during operation BEFORE TOUCHING parts of the oven always remove2. The cooking time stops counting down Relay stops functioning As the door is opened if the contact of primary switch and relay 2 and or secondary switch fails to open the fuse opens due to the large current surge caused by the monitor switch activation which in turn stops magnetron oscillation PRIMARY SWITCH FUSE H V TRANS FORMER MONITOR SWITCH SECONDARY 97 switcH OTO RELAY 2 1 00 MICOM CONTROLLER SERVICE INFORMATION TOOLS AND MEASURING INSTRUMENTS NECESSARY TOOLS Tools normally used for TV servicing are sufficient Standard tools are listed below Diagonal pliers Long nose pliers Phillips screwdriver Flat blade screwdriver Wrench size 5mm Nutdriver size 5mm Adjustable wrench Soldering iron Solder Vinyl insulation tape Polishing cloth MICROWAVE LEAKAGE TEST CAUTIONS Be sure to check microwave leakage prior to servicing the oven if the oven is operative prior to servicing The service personnel should inform the manufacture importer or assembler of any certified oven unit found to have a microwave emission level in excess of 5 mW cm and should repair any unit found to have excessive emission levels at no cost to the owner and should ascertain the cause of the excessive leakage The service personnel should instruct the owner not to use the unit until the oven has been broug
3. SWITCH RELAY2 SECONDARY 92 SWITCH CONTROLLER 77 The fan motor rotates and cools the magnetron by blowing the air coming from the intake on the baseplate The air is also directed into the oven to exhaust the vapor in the oven through the upper plate Cooking time starts counting down 3 2 volts AC is generated from the filament winding of the high voltage transformer This 3 2 volts is applied to the magnetron to heat the magnetron filament through two noise preventing choke coils A high voltage of approximately 2100 volts AC is generated in the secondary of the high voltage transformer which is increased by the action of the high voltage diode and charging of the high voltage capacitor The negative 4 000 Volts DC is applied to the filament of the magnetron WHEN THE OVEN IS SET AT ANY LEVEL EXCEPT MAXIMUM The micom controller controls the ON OFF time of relay 2 by the applied signal to vary the average output 4 4 power of microwave oven as POWER LEVEL refer to page 1 1 WHEN THE DOOR IS OPENED DURING COOKING Both the primary switch and relay 2 are cut off primary winding voltage of the high voltage transformer ON OFF of relay 2 is coupled electrically with opening and closing of the secondary switch When the door is opened the secondary switch is opened and when the door is closed the secondary switch is closed
4. START 2ND STAGE STOP POWER TIME POWER TIME START 6 AUTO DEFROST COOKING AUTO NUMBER OF STOP gt WEIGHT START DEFROST kg 7 CHILD LOCK This oven has a CHILD LOCK feature TO SET CHILD LOCK Touch the STOP pad e Touch STOP L appear in the display TO CANCEL CHILD LOCK Touch the STOP pad e touch STOP pad L disappears 8 AUTO COOK AUTO 9 QUICK MENU QUICK STOP MENU START SCHEMATIC DIAGRAM HOLONNW T sisseuo o y Jo euruua Nau N9 ya yy ayy Buoys Ag Joyoedeo m ee ONIDIAYIS AYOjAAG un us er JOVLIOA LNVH Y39YYH93A 13 Y3193NNO930 INDINHOFL NOILNSAYSLNI LNVAV FOLLON LNOHLIM uspe yua OL LOAPANs 38 LINDUIO E ue e JOA JojesuepuoxsbBunuuedsu o JAVMOSOIMN SI ION 9NIMOOO C P A d H INNLHOV
5. Used to select the auto weight defrost Quick Menu 1 Oatmeal 4 Hotdog D cuu 5 CLOCK Used to set the time of day 1 6 STOP CLEAR Used to stop over and clear all T Cook entries except time of day LINE 7 AUTO COOK Used to cook the foods listed by As one touch IE 8 AUTO REHEAT Used to select the auto reheat 9 AUTO DEFROST Used to select the auto weight defrost 10 MORE LESS Used to change the cooking time amp desired weight 11 START QUICK START One tap allows over to begin functioning Stop Clear Start Quick Start 4 1 OPERATING SEQUENCE The following is a description of component functions during oven operation 1 SETTING THE CLOCK STOP CLOCK gt CLOCK NOTE 1 This is a 24 hour clock 2 Clock will operate as long as power is applied to the oven 2 CANCEL FUNCTION Touch the STOP pad whenever you need to cancel an entry or a function currently in use The display will return either to the last item entered or to the clock 3 QUICK START STOP START 4 MICROWAVE COOKING STOP 3 gt POWER TIME START 4 2 5 MULTI STAGE MICROWAVE COOKING 1ST STAGE STOP gt POWER TIME 5
6. replacing the magnetron be sure to install the magnetron gasket in the correct position and be sure that the gasket is in good condition After replacing the magnetron check for microwave leakage with a survey meter around the magnetron Microwave energy must be below the limit of 5 mW cm With 275 ml water load Make sure that gasket is rigidly attached to the magnetron To prevent microwave leakage tighten the mounting screws properly making sure there is no gap between the waveguide and the magnetron Waveguide Dome Waveguide Bracket Magnetron Gasket Magnetron J REMOVING THE TURNTABLE MOTOR 1 Remove the turntable Remove the Rotating Ring Lay the unit down on its back Remove the turntable motor cover The turntable base cover is easily removed by pinching the six parts with a wire cutting 5 Disconnect the leadwire from the turntable motor terminals 6 Remove the screw securing the turntable motor to the oven cavity ASS Y 7 After repairing the motor rotate the removed turntable motor cover 8 Fit the turntable motor cover s projecting part to the base plate slit NOTE 1 Remove the wire lead from the turntable motor VERY CAREFULLY 2 Be sure to grasp the connector not the wires when removing gt 4 Turntable Motor PCB ASSEMBLY REMOVAL 1 Remove the control panel assembly from the c
7. the power plug from the outlet For about 30 seconds after the oven stops an electric charge remains in the high voltage capacitor When replacing or checking you must discharge the high voltage capacitor by shorting across the two terminals with an insulated screwdriver Remove your watches whenever working close to or replacing the Magnetron NEVER operate the oven with no load NEVER injure the door seal and front plate of the oven cavity NEVER put iron tools on the magnetron NEVER put anything into the latch hole and the interlock switches area MICROWAVE RADIATION Personnel should not be exposed to the microwave energy which may radiate from the magnetron or other microwave generating device if it is improperly used or connection All input and output microwave connections waveguide flange and gasket must be secure never operate the device without a microwave energy absorbing load attached Never look into an open waveguide or antenna while the device is energized Proper operation of the microwave oven requires that the magnetron be assembled to the waveguide and cavity Never operate the magnetron unless it is properly installed Be sure that the magnetron gasket is properly installed around the dome of the tube whenever installing the magnetron ANTENNA FILAMENT TERMINALS MAGNETRON CHASSIS GROUND MAGNETRON THE OVEN IS TO BE SERVICED ONLY BY PROPERLY QUALIFIED SERV
8. CORRECT POSITION MAGNETRON TRANSFORMER PRIMARY FIG 1 bid CIRCUIT PROTECTOR 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 PRIMARY INTERLOCK SWITCH TEST When the door release button is depressed slowly with the door closed an audible click should be heard at the same time or successively at intervals When the button is released slowly the latches should activate the switches with an audible click If the latches do not activate the switches when the door is closed the switches should be a adjusted in accordance with the adjustment procedure Disconnect the wire lead from the primary switch Connect the ohmmeter leads to the common COM and normally open NO terminal of the switch The meter should indicate an open circuit in the door open condition When the door is closed the meter should indicate a closed circuit When the primary switch operation is abnormal make the necessary adjustment or replace the switch only with the same type of switch COMPONENTS TEST PROCEDURE B SECONDARY INTERLOCK SWITCH TEST Disconnect the wire lead fr
9. GAN3d0 HOOQ 1 ILON x IONLNOO BOLOVAVONH den leo wm aal ce 3SNIAH 1007 21 s 2 3ALVNSHALETV NO 52 HOLIMS AYWONOIIS HM LB z e LL asis WM 3a0IQAH Wal BIB ig 1 y 2 00 KO a WLL TO L E T LNANI E 9 0 0 3snd HM Ng HOLIMS IVLSOWYSHL OILVIN3HOS 4 3 CIRCUIT DESCRIPTION GENERAL DETAILS The low voltage transformer supplies the necessary voltage to the micom controller when power cord is plugged in When the door is closed the primary switch is ON the secondary switch is ON and the monitor switch opens contact COM and NO WHEN SELECTING COOKING POWER LEVEL AND TIME micom controller memorizes the function you set The time you set appears in the display window Each indicator light turns on to indicate that the stage has been set WHEN TOUCHING THE START PAD The coil of the relay is energized by the micom controller Power input is supplied to the high voltage transformer through the fuse to the primary switch and relay 2 Turntable rotates PRIMARY FUSE SWITCH O O O MONITOR
10. ICE PERSONNEL INSTALLATIONS BEFORE YOU BEGIN READ THE FOLLOWING INSTRUCTIONS COMPLETELY AND CAREFULLY INSTALLING Empty the microwave oven and clean inside it with a soft damp cloth Check for damage such as misaligned door damage around the door or dents inside the cavity or on the exterior Put the oven on a counter table or shelf that is strong enough to hold the oven and the food and utensils you put in it The control panel side of the oven is the heavy side Use care when handling Do not block the vent and the air intake openings Blocking vent or air intake openings can cause damage to the oven and poor cooking results Make sure the microwave oven legs are in place to ensure proper air flow The oven should not be installed in any area where heat and steam are generated because they may damage the electronic or mechanical parts of the unit Do not install the oven next to a conventional surface unit or above a conventional wall oven Use microwave oven in an ambient temperature less than 104 F 40 C Place the microwave oven on a sturdy and flat surface at least 10 cm 4 inches from the wall Place the microwave oven as far away as possible from TV RADIO COMPUTER etc to prevent interference Do not touch the front glass during or after cooking of the Grill and Combination mode This glass is very hot during heater operating Do not operate the oven at microwa
11. SULT CAUSE REMEDY Output is full power Disconnect the Abnormal Defective PCB Replace PCB j assembly assembly NOTE Make sure the wire leads correct position When Removing the wire leads from the parts be sure to grasp the connector not the wires When removing the magnetron be sure to install the magnetron gasket in the correct position and in good condition 5 16 EV Check the Rating Model No O LG ECN MS 2344B 01 MOD 5 2344 230V 50Hz 1250W 2450MHz 850W E 1250w S N 230V 50Hz 1250W 2450MHz 850W E 1250w EN PLODED V IEW LG ECN MS 2544B MOD MS 2544B INTRODUCTION MODEL MS 2344B MS 2544B CAVITY PARTS INTERIOR PARTS BASE PLATE PARTS DOOR PARTS LATCH BOARD PARTS CONTROL PANEL PARTS 6 1 EV DOOR PARTS 6 2 CONTROL PANEL PARTS 6 3 EV OVEN CAVITY PARTS San AG v amp CA NS 0 2 X amp 6 4 EV LATCH BOARD PARTS 6 5 EV INTERIOR PARTS 55 P NY N LEA TN a A 2 5 T AA 5 9 gm EN 1 xor 95692 feu 0 peg c 6 6 BASE PLATE PARTS
12. TAGE CAPACITOR AND REMOVING THE WIRE LEADS FROM THE PRIMARY WINDING OF THE HIGH VOLTAGE TRANSFORMER SEE PAGE 2 1 2 ALL OPERATIONAL CHECKS WITH MICROWAVE ENERGY MUST BE DONE WITH A LOAD 1 LITER OF WATER IN CONTAINER IN THE OVEN COMPONENTS TEST PROCEDURE RESULTS HIGH VOLTAGE TRANSFORMER Wire leads removed FILAMENT WINDING TERMINAL SECONDARY TERMINAL PRIMARY TERMINAL 1 Measure the resistance Ohm meter scale Rx1 and Rx100 Primary winding Approx 2 5 Q e Secondary winding Approx 110 Q Filament winding Less than 0 4 Q Measure the resistance Ohm meter scale Rx1000 e Primary winding to ground Normal Filament winding to ground Normal MAGNETRON Wire leads removed Measure the resistance Ohm meter scale Rx1 Normal Less than 1 Q Filament terminal Measure the resistance Ohm meter scale Rx1000 Normal ee Filament to chassis 5 8 COMPONENTS TEST PROCEDURE RESULTS 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 CAPACITOR Measure the resistance Ohm meter scale Rx1000 Terminal to terminal Normal Momentarily indicates several ohms and then gradually returns to infinite Measure the resistance Ohm meter scale Rx1000 Terminal to case Normal HIGH VOLTAGE DIODE NO
13. TE Some inexpensive meters may indicate infinite resistance in both direction Measure the continuity Forward Ohm meter scale Rx10000 Normal Continuity Abnormal Measure the continuity Reverse Ohm meter scale Rx10000 E ce 5 9 Normal Abnormal Continuity COMPONENTS TEST PROCEDURE RESULTS RELAY 2 Check for continuity of relay 2 with an ohm meter Remove wire leads from relay 2 and operate the unit Transformer POWER LEVEL 20 6 sec 40 10 sec 60 14 sec 80 18 sec 100 22 sec FAN MOTOR Wire leads removed Measure the resistance Ohm meter scale R x 100 Normal 350 4500 Abnormal or several Q TURNTABLE MOTOR Wire leads removed Measure the resistance Ohm meter scale R x 1000 Normal Approx 16 K Abnormal e or several Q NOTE MICROWAVE LEAKAGE TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS SERVICED FOR ANY REASON MAKE SURE THE WIRE LEADS ARE IN THE CORRECT POSITION WHEN REMOVING THE WIRE LEADS FROM THE PARTS BE SURE TO GRASP THE CONNECTOR NOT THE WIRES 5 10 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 damage this co
14. Website http biz lgservice com LG MICROWAVE OVEN MODEL 5 2344 MS 2544B CAUTION BEFORE SERVICING THE UNIT READ THE SAFETY PRECAUTIONS IN THIS MANUAL November 2004 P NO 3828W5S4281 Printed in Korea 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 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 loosening of hinges and latches 5 evidence of dropping or abuse C Before turning on microwave power for any service test or inspection within the microwave generating compartments check the magnetron wave guide or transmission line and cavity for proper alignment integrity and connections D Any defective or misadjusted components in the interlock monitor door seal and microwave generation and transmission systems shall be repaired replaced or adjusted by procedures descr
15. avity Refer to control panel assembly removal on previous page 2 Remove screws which hold the PCB SUB ASS Y to the control panel 3 Disconnect the flat cable from the PCB SUB ASS Y and take off the PCB SUB ASS Y Timer Motor Control Panel 5 6 L INTERLOCK SYSTEM 1 INTERLOCK MECHANISM The door lock mechanism is a device which has been specially designed to eliminate completely microwave activity when the door is opened during cooking and thus to prevent the danger resulting from the microwave leakage 2 MOUNTING OF THE PRIMARY MONITOR SECONDARY SWITCHES TO THE LATCH BOARD ADJUSTMENT DIRECTION 9 SWITCH MONITOR SWITCH SECONDARY SWITCH 3 INSTALLATION AND ADJUSTMENT OF THE LATCH BOARD TO THE OVEN ASSEMBLY Mount the latch board to the oven assembly Adjust the latch board in the arrow direction so that oven door will not have any play in it when the door is closed Tighten the mounting screw Check for play in the door by pushing the door release button Door movement should be les than 0 5 mm 1 64 inch Don t push the door release button while making adjustment Make sure that the latch moves smoothly after adjustment are completed and that the screws are tight Make sure the primary monitor and secondary switches operate properly by following the continuity test procedure CAUTION CHECK THE
16. control panel edges of the case 3 Lift control panel ASS Y from the oven by the tab The outer case must be moved backward to be lifted unhooked off B POWER SUPPLY CORD 1 Remove the outer case 2 Disconnect two terminals and remove one screw of the earth terminal CAUTION DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE SERVICING refer to page 2 1 5 3 DOOR GROSS ASSEMBLY REMOVAL 1 Open the door 2 Remove the choke cover cap very carefully with a flat blade screwdriver CAUTION Be careful not to damage door seal plate by screwdriver 3 Lift up and push the door NOTE After replacing the door be sure to check that the primary switch monitor switch and secondary switch operate normally 2 After replacing the door check for microwave energy leakage with a survey meter Microwave energy must be below the limit of 5 mW cm with a 275 ml water load 3 When mounting the door assembly to the oven assembly be sure to adjust the door assembly parallel to the chassis Also adjust so the door has no play between the inner door surface and oven frame assembly If the door assembly is not mounted properly microwaves may leak from the clearance between the door and the oven Remove Hinge Plate Remove Door Assembly 5 4 E HIGH VOLTAGE TRANSFORMER REMOVAL 1 Discharge the high voltage capacitor 2 Disconnect the leadwire from magnetron high voltage t
17. d allowing it to touch the oven wall Do not use metallic ware for cooking except where noted in the cooking guide Ceramic ware trimmed in gold or silver powder is used Do not use any type of cookware with metallic trimming Inconsistent intensity of microwave by their characteristics 1 Wrap the thinner part with aluminum foil 2 Use plastic wrap or lid 3 Stir once or twice while cooking soup cocoa or milk etc IExcessive weight on tray or improperly balanced 5 11 Distribute food evenly Cook smaller portions and or use lighter weight cookware TROUBLE 1 Oven lamp does not turn on when the timer knob is pushed with door closed 1 Incomplete segments Segment missing Partial segment missing Digit flickering NOTE Slight flickering is normal mb Colon does not turn on or blink A distinct change in the brightness of one or more numbers in display One or more digits in the display are not lighting Display indicates a number different from one touched for example key in 5 and 3 appears in the display Specific numbers for example 7 or 9 will not display when key pad is touched Display does not count down with time blinking or up with clock operation Display obviously jumps in time while counting down Display counts down too fast while coo
18. e diameter of approximately 190 mm Temperature after bown The oven and the empty vessel are at ambient Weight of bowl temperature prior to the start of the test The initial temperature T1 of the water is 10 2 C It is measured immediately before the water is added to the vessel After addition of the water to the vessel the load is immediately placed on the center of the turntable which is in the lowest position and the microwave power switched on The time T for the temperature of the water to rise by a value AT of 10 2 K is measured where T is the time is measured while the microwave generator is operating at full power Magnetron filament heat up time is not included about 3 sec The water is stirred to equalize temperature throughout the vessel prior to measuring the final water temperature Stirring devices and measuring instruments are selected in order to minimize addition or removal of in seconds and AT is the temperature rise The initial heat and final water temperatures are selected so that the maximum difference between the final water WATER LOAD temperature and the ambient temperature is 5 K 27 TURNTABLE A OUTER CASE REMOVAL C CONTROL PANEL ASSEMBLY 1 Disconnect the leadwire from the PCB SUB ASS Y 1 Disconnect the power supply cord from the outlet 2 Remove the screws for the earth and securing the 2 Remove the screws from the rear and along side
19. ht into compliance If the oven operates with the door open the service personnel should Tell the user not to operate the oven Contact the manufacturer The service personnel should check all surface and vent openings for microwave leakage Check for microwave leakage after every servicing The power density of the microwave radiation leakage emitted by the microwave oven should not exceed 4 mW cm Always start measuring of an unknown field to assure safety for operating personnel from radiation leakage 5 1 NECESSARY MEASURING INSTRUMENTS TESTER VOLTS DC AC Ohmmeter Microwave survey meter Holaday HI 1500 HI 1501 Narda 8100 8200 e Inch scale 600 cc non conductive material beaker glass or plastic inside diameter approx 8 5 cm 3 2 in Cylindrical and made of borosilicate glass vessel max thickness 3 mm outside diameter approx 190mm height approx 90mm Glass thermometer 100 C or 212 F 1 deg scale MEASURING MICROWAVE ENERGY LEAKAGE e Pour 275 15cc of 20 5 C 68 9 F water in a beaker which is graduated to 600 cc and place the beaker on the center of the turntable Set the energy leakage monitor to 2450 MHz and use it following the manufacturer s recommended test procedure to assure correct result When measuring the leakage always use the 2 inch bcm spacer supplied with the probe Operate the oven at its maximum output Measure the microwave radiation u
20. ibed in this manual before the oven is released to the owner E A microwave leakage check to verify compliance with the Federal Performance Standard should be performed on each oven prior to release to the owner CAUTION MICROWAVE RADIATION DO NOT BECOME EXPOSED TO RADIATION FROM THE MICROWAVE GENERATOR OR OTHER PARTS CONDUCTING MICROWAVE ENERGY CONTENTS Page GAFETY PRECAUTIONS 23 5 3 95825880 08853080989 0888 1918 Inside front cover SPECIFICATIONS 1 1 CAUTIONS SERFRRPERNPEENSEDRPEDRPEONFEOR SE dada ada 2 1 INSTALLATION S naaa A 3 1 OPERATING INSTRUCTIONS sie 4 1 FEATURES nnn 4 1 CONTROL PANEL inercia 4 1 OPERATING 4 2 SCHEMATIC DIAGRAM 4 3 CIRCUIT DESCRIPTION 4 4 SERVICE INFORMATION seinen 5 1 TOOLS AND MEASURING INSTRUMENTS lt lt 5 1 MICROWAVE LEAKAGE TEST arco taa inta ka 5 1 MEASUREMENT OF MICROWAVE POWER OUTPUT n nnne 5 3 DISASSEMBLY AND ADJUSTMENT 5 3 INTERLOCK CONTINUITY 6 5 7 COMPONENT TEST PROCEDURE
21. king Each indicator light does not turn on after setting cooking cycle Display time of day does not reappear when cooking is finished Beep sound is not heard when correct key is touched different from one touched 4 Random programming when touching other pads 5 Display is fixed at some figure and can not accept any input 5 12 CONDITION CHECK RESULT CAUSE REMEDY 1 No input can be Check the conn Colin Defective PCB Replace PCB programmed ection between d assembly assembly membrane key assembly and Loose onnect them PCB assembly connection tightly 2 Some inputs Replace key Everything works Defective key Replace key cannot be membrane as specified membrane membrane programmed assembly and assembly assembly check operation 3 Display shows a Replace PCB number or figure Sill nave trouble connection assembly 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 Check continuit TE Malfunction of the Replace primar 1 Fuse blows Neck con inullY Continuity of monitor monito
22. ntrol panel body 1 Check grounding before checking for trouble 2 Be careful of the high voltage circuit 3 Discharge the high voltage capacitor See page 2 1 4 When checking the continuity of the switches or of the high voltage transformer disconnect one lead wire from these parts and then check continuity with the AC plug removed do otherwise may result in a false reading or damage to your meter 5 Do not touch any part of the circuitry on the digital programmer circuit since static electric discharge may Always touch yourself ground while working on this panel to discharge any static charge built up in your CONDITION Microwave oven CAUSE REMEDY does not work Inserting many plug into one plug outlet and using them at the same time causes overloading Avoid using other electrical appliances when you use the microwave oven Microwave oven plug is not inserted tightly Insert microwave oven plug securely Output power is too low Sparks occurring Uneven cooking Turntable drags or makes noise Low AC input voltage Use the microwave oven at adequate line voltage Food temperature is too low This may not be a defect It is possible that the food should be cooked for a longer time period Using metallic ware an
23. of secondary secondary switch secondary switch when touching switch with START pad door closed Continuity 2 Fan motor or oven lamp do not turn on Check continuity of secondary No continuity Defective P C B Replace P C B switch with gt assembly gt assembly door closed Continuity gt Loose connection gt a then Check fan motor gt No continuity gt Defective fan Replace fan motor motor Check oven lamp No continuity Defective oven lamp Replace oven lamp S Normal TROUBLE 4 Oven seems to be operation but little heat is produced in oven load CONDITION CHECK RESULT CAUSE REMEDY Output is low Check the Lower than 90 of Decrease inpower Suggest customer power source rating voltage source voltage contact local voltage with load electric power Le Normal utility co or qualified electrician Disconnect the wire leads from Abnormal Defective P C B Replace P C B E relay 2 and check assembly assembly on and off time with multitester gt Abnormal Measure the Abnormal Defective Replace Abnormal output magnetron magnetron NOTE Simple test of power out
24. om the secondary switch Connect the ohmmeter leads to the common COM and normally open NO terminals of the switch The meter should indicate a open circuit in the door open condition When the door is closed meter should indicate an closed circuit When the secondary switch operation is abnormal make the necessary adjustment or replace the switch only with the same type of switch C MONITOR SWITCH TEST Disconnect the wire lead from the monitor switch Connect the ohmmeter leads to the common COM and normally closed NC terminals of the switch The meter should indicate closed circuit in the door open condition When the door is closed meter should indicate an open circuit When the monitor switch operation is abnormal replace with the same type of switch NOTE After repairing the door or the interlock system it is necessary to do this continuity test before operating the oven RESULTS SWITCHES Wire leads removed Check for continuity of the switch with an Ohm meter Door close Door open Primary Switch EN ES Monitor Switch Secondary Switch 5 7 NOTE After checking for the continuity of switches make sure that are connected correctly 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 VOL
25. put conducted by heating one liter water for one min if available 5 14 TROUBLE 5 No microwave oscillation even though oven lamp and fan motor run Display operates properly Normal CONDITION CHECK RESULT CAUSE REMEDY 40 Disconnect the No continuity oe RCE an Ree 1 wire leads from RE 2 check continuity Continuity of relay2 Operate the unit Check circuit Abnormal Defective circuit Replace circuit protector protector protector Normal Check high vol Abnormal Defective high Replace high tage transformer voltage voltage transformer transformer Normal Check high vol Abnormal Defective high Replace high tage capacitor voltage capacitor voltage capacitor gt Check high vol Abnormal Defective high Replace high tage diode voltage diode voltage diode Normal Check Defective Replace magnetron magnetron magnetron 5 15 TROUBLE 5 No microwave oscillation even though oven lamp and fan motor run Display operates properly when you set lower power level wire leads from relay 2 and check continuity relay 2 Operate the unit CONDITION CHECK RE
26. r switch and monitor switch with switches door closed No continuity 2 1 Replace fuse Check continuity x Continuity Shorted contact at gt Replace primary a or primary the primary switch and monitor switch with switches door opened No continuity Disconnect one Noral Defective high Replace high side of the wire voltage capacitor voltage capacitor lead connected from transformer 00 Defective high volt Replace high volt Fuse blows again gt o to the high age transformer age transformer voltage capacitor and operate the unit NOTE All these switches must be replaced at the same time Refer to page 5 6 5 7 2 Fuse does not blow Check continuity M Defective mag Replace mag of magnetron netron thermostat netron thermostat thermostat Continuity Check continuity No continuity Replace power of power supply cord 5 13 Defective power supply cord supply cord 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 1 Setting time does Check continuity No continuity gt Defective Replace not count down
27. ransformer and capacitor 3 Remove the screw holding the high voltage transformer to the baseplate F FAN MOTOR ASSEMBLY REMOVAL 1 Discharge the high voltage capacitor 2 Disconnect the leadwire from fan motor noise filter and high voltage capacitor 3 Remove the two screws holding the the suction guide ASS Y to the oven cavity and remove the high voltage diode earth screw 4 Remove the screw of the capacitor bracket 5 Remove the two screws holding the fan motor ASS Y to the suction guide ASS Y G HIGH VOLTAGE CAPACITOR AND DIODE REMOVAL 1 Discharge the high voltage capacitor 2 Disconnect the leadwire from fan motor noise filter and high voltage capacitor 3 Remove the screw holding the suction guide ASS Y to the oven cavity and remove the high voltage diode earth screw 4 Remove the screw holding the high voltage capacitor bracket Fan Motor ASS Suction Guide AIR DUCT ASSEMBLY REMOVAL 1 Disconnect the leadwire from lamp 2 Remove the mounting screw to Latch Board 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 3 Remove the magnetron ASS Y until the tube is clear from the waveguide NOTE 1 When removing the magnetron make sure its dome does not hit any adjacent parts or it may be damaged 2 When
28. result The test probe must be held with the grip portion of the handle A false reading may result if the operator s hand is between the handle and the probe When testing near a corner of the door keep the probe perpendicular to the surface making sure the probe horizontally along the oven surface this may possibly cause probe damage RECORD KEEPING AND NOTIFICATION AFTER MEASUREMENT After adjustment and repair of any microwave energy interruption or microwave energy blocking device record the measured values for future reference Also enter the information on the service invoice The microwave energy leakage should not be more than 4 mW cm sq after determining that all parts are in good condition functioning properly and genuine replacement parts which are listed in this manual have been used At least once a year have the electromagnetic energy leakage monitor checked for calibration by its manufacturer 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 AT 0 55 X Tz To XM a load of 1000 5 g of potable water P The water is contained in a cylindrical borosilicate glass T vessel having a maximum material thickness of 3 mm e Temperature after heating and an outsid
29. sing and electromagnetic radiation monitor by holding the probe perpendicular to the surface being measured Move probe along shaded area I B Bg gg Probe scanning speed Less than 2 5 cm sec 1in sec MEASUREMENT WITH OUTER CASE REMOVED When you replace the magnetron measure for microwave energy leakage before the outer case is installed and after all necessary components are replaced or adjusted Special care should be taken in measuring the following parts Circled area of below Fig Around the magnetron The waveguide WARNING AVOID CONTACTING ANY HIGH VOLTAGE PARTS Magnetron H V Transformer H V Capacitor H V Cable Ass y H V Circuit Protector MEASUREMENT WITH A FULLY ASSEMBLED OVEN After all components including the outer case are fully assembled measure for microwave energy leakage around the door viewing window the exhaust opening and air inlet openings Microwave energy leakage must not exceed the values prescribed below NOTE Leakage with the outer case removedless than 5 mW cm sq Leakage for a fully assembled oven Before the latch switch primary is interrupted with the door in a slightly opened position less than 2 mW cm sq 5 2 NOTES WHEN MEASURING Do not exceed meter full scale deflection The test probe must be removed no faster than 1 inch sec 2 5 cm sec along the shaded area otherwise a false reading may
30. ve and combination mode with Grill rack placed in the cavity when the oven is empty 10cm EARTHING INSTRUCTIONS This microwave oven is designed to be used in a fully earthed condition It is imperative therefore to make sure it is properly earthed before servicing WARNING THIS APPLIANCE MUST BE EARTHED IMPORTANT The wires in this mains lead are colored in accordance with the following code Green and yellow Earth Blue Neutral Brown Live As the colors of the wires in the mains lead of this appliance may not correspond with the colored markings identifying the terminals in your plug proceed as follows The wire which is colored green and yellow must be connected to the terminal in the plug which is marked with the letter E or by the earth symbol or colored green or green and yellow The wire which is colored blue must be connected to the terminal in the plug which is marked with the letter N or colored black The wire which is colored brown must be connected to the terminal in the plug which is marked with the letter L or colored red OPERATING INSTRUCTIONS FEATURES Oven Front Plate Window Door Screen Door Seal Control Panel Safety Door Lock System Glass Tray Rotating Ring CONTROL PANEL 1 QUICK MENU 2 POWER Used to select the desired power level for cooking 3 COOK TIME Used to cook food for a desired time 4 QUICK DEPROST
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