Electrolux mwo_EC20GBSK
Contents
1. E ee ee ESRISEERT ERIT ER Elias EEE BE 53 at Ha el ie Ho o Eq O m EE E p JS890703 20 I SDISDISDISDISDISDISDISDISDISDIE DI EXPLODED VIEW 1 2 3 000 D _ _ _ _ _ _ _ 00 024 AREA HOLDER GLASS 2 E DOS Gasket Door 007 Panel Door 006 AWE Barrier Screen 0 005 ams Barrier Screen 502 f RS 13 8PBHC 5 004 ASSY BRKT Hinge T C26 SWITCH CIRCUIT 1 DOS Tit Spring Latch C18 46 PCB ASSY 1 002 Latch COS DECO MEMBRANE 1 001 ASS Y Door Frame 01 Panel Control 1 000 ret ASS Y DOOR COO ASS Y C PANE 1 NO 34k Hj 8 NO Sasa gt 1 206 XX N ume 4 mies pag2. OO EO ORO RO RO RO RC ROT RO RO RO RO RO RC ERO EC EO EO ERO EO SAMT ef gm 8 4 Electrolux SERVICE MANUAL O 00000 JJO000 000200 MICROWAVE EC20GBSK MMZ Please read this service manual carefully before servicing your machine Retain it for future reference Record model name amp serial number of the machine Please quote this information when you require service MICROWAVE OVEN MODEL EC20GBSK MMZ USER GUIDE PRINTING IN BLUE amp Black COLOUR HH 5 size Contents SAFETY PRECAUTIONS CAUTIONS THE HEATING PRINCIPLE OF MICROWAVE INSTALLATIONS CIRCUIT DIAGRAM CIRCUIT DESCRIPTION SERVICE INFORMATION TOOLS AND MEASURING INSTRUMENTS MICROWAVE LEAKAGE TEST NECESSARY MEASURING INSTRUMENTS MEASURING MICROWAVE ENERGY LEAKAGE MEASUREMENT WITH OUTER CASE REMOVED MEASUREMENT WITH A FULLY ASSEMBLED OVEN RECORD KEEPING amp NOTIFICATION AFTER MEASUREMENT MEASUREMENT OF MICROWAVE POWER OUTPUT TROUBLE SHOOTING PROCEDURES MEANS OF THE BREAKDOWN EXAMINING SPOT EXAMINING STEPS OF THE MWO REPAIRING METHOD OF SEVERAL BREAKDOWN MOTOR TEST PROCEDURE COMMON BREAKDOWN amp MEANS OF REPAIRING IMPORTANT THINGS TO DO PRIOR TO CRITICAL PART SERVICING SAFETY CHECKS AND TESTS AFTER SERVING EXPLODED VIEW EXPLODE CODE PARTS NAME amp SAP CODE page 2 3 3 4 o 10 11 11 11 13 14 15 16 1
3. HERF ECAS 44 F U ait aM EC20GBSK 1 7 3 A 21 EXPLODE CODE PARTS NAME amp SAP CODE MODEL NO EXPLODE CODE PARTS NAME SAP CODE EC20GBSK 00 CAVITY ASS Y 1100051131 EC20GBSK 1 COVER WAVE GUIDE 1100051132 EC20GBSK BASE PLATE 1100051133 EC20GBSK 2 1100051134 EC20GBSK BRAKET HINGE U ASS Y 1100051135 EC20GBSK CONROL PANEL ASS Y 1200028456 EC20GBSK co1 CONROL PANEL 1100051136 EC20GBSK cos DECO MEMBRANE 1100051137 EC20GBSK 18 PCBASSY 1100051138 EC20GBSK 26 SWITCH CIRCUIT 1100051139 EC20GBSK DOO ASS Y D PANEL 1100051140 EC20GBSK 201 DOOR FRAME ASS Y 1100051141 EC20GBSK 002 LATCH 1100051142 EC20GBSK LATCH SPRING 1100051143 EC20GBSK 4 BRAKET HINGE ASS Y 1100051144 EC20GBSK 005 BARRIER SCREEN 1 1100051145 EC20GBSK BARRIER SCREEN 0 1100051146 EC20GBSK DO7 DOOR PANEL 1100051147 EC20GBSK Dos DOOR GASKET 1100051148 EC20GBSK D24 HOLDER GLASS 1100051149 EC20GBSK E01 MAGNETRON 1200028457 EC20GBSK E05 H V TRANSFORMER 1100051150 EC20GBSK E06 CAPACITOR 1100051151 EC20GBSK 7 DIODE 1100051152 EC20GBSK E10 FUSE HOLDER 1100051153 EC20GBSK E11 FUSE 1100051154 EC20GBSK E13 LAMP 1100051155 EC20GBSK E14 LAMP SOKET 1100051156 EC20GBSK E16 POWER CORD ASS Y 1100044884 EC20GBSK E28 H V FUSE ASS Y 1100051157 EC20GBSK E30 TH
4. be more than 1 0 mW cm2 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 MEASUREMENT OF MICROWAVE POWER OUTPUT Microwave power output measurement is made with the microwave oven supplied at its rated voltage and operated at its maximum microwave power setting with a load of 1000 5 g of potable water The water is contained in a cylindrical borosilicate glass vessel having a maximum material thickness of 3 mm and an outside diameter of approximately 190mm The oven and the empty vessel are at ambient temperature prior to the start of the test The initial temperature 1 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 T of 10 2 K is measured where T is the time in seconds and T is the temperature rise The initial and final water temperatures are selected so that the maximum difference between the final water temperature and the ambient temperature is 2 The microwave power output P in watts is calculated approximately from the following fo
5. MEASURING INSTRUMENTS TESTER VOLTS DC AC Ohmmeter Microwave survey meter Holaday HI 1710 A Narda 8100 8200 Inch scale 600 cc non conductive material beaker glass or plastic inside diameter approx 8 5 cm 31 2 in Oylindrical 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 SERVICE INFORMATION MEASURING MICROWAVE ENERGY LEAKAGE Pour 275 15 cc 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 2 450 MHz and use it following the manufacturer s recommended test procedure to assure correct result When measuring the leakage always use the 2 inch 5 cm spacer supplied with the probe Operate the oven at its maximum output Measure the microwave radiation using and pod electromagnetic radiation monitor by holding the 47 probe perpendicular to the surface being Y measured Move probe along shaded area Probe scanning speed Less than 2 5 cm 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 Around the magnetron The waveguide WARNING AVOID CONTA
6. MINNS Ta H V DIODE 355 E HCH VOLTAGE TRANSFONER C E RELAY BRR Miss RW SECONDARY INTERLOCK 1 SWITCH 00 j BL LG g __ a _ CONTROL PMB ASSY EM _ __ D CONDITION NOTE DOOR CLOSED QD OVEN LAMP BLACK BL BLUE COOK OFF FAN MOTOR RD RED BR BROWN TURNTABLE MOTOR WH WHITE GREEN YELLOW YW YELLOW CIRCUIT DIAGRAM SE pray S defe RRS ecocesk F 51 mm F mig emas 1 Y CIRCUIT DESCRIPTION As the door is closed the contact of MONITOR SWITCH opens This switch creates the short circuit to blow fuse during operation under abnormal condition ie should the contacts of primary and secondary switch fail to open the circuit The latches secured by latch board The oven light turns on while the oven is in operation MICROWAVE POWER LEVEL AND COOKING TIME SET The contacts of the timer switch changes to ON position when the timer knob is rotated While power control knob is set The contacts of primary and secondary switch close the circuit POWER Input Volts AC
7. outlet Check the door for warped or damaged areas Check the hinges for broken or worn areas Check other areas such as cracked from glass broken door latched worn cracked viewing screen and etc 3 2 After determining the door assembly should be replaced check the parts list for the correct part number All oven door components must be ordered directly from the manufacturer or its authorized distributor 4 Magnetron Replacement 4 1 Check for the presence of the wire mesh gasket before installation 4 2 Conduct a Microwave Leakage Test at the magnetron area prior to installing the top cover 18 SERVICE INFORMATION SAFETY CHECKS AND TESTS AFTER SERVING Constructional Checks If mechanical or electrical electronic parts have been replaced be sure to follow the following steps 1 1 Check for correct wiring adequate mechanical decrements of parts and firm connectors 1 2 Check for adequate grounding 1 3 Check the following items before turning the oven ON 1 Proper door closing seal choke surfaces and hinges 2 No outer case damage 3 Proper interlock and monitor operations Insulation Resistance Test If the low voltage power supply has been repaired use a 500 Mega ohmmeter to measure the resistance between the primary Line and Neutral of the power plug and operator accessible metal parts The resistance should be no less than 2 Mega Ohms Repair the oven again when necessary 19
8. 5 4 The resistance value of the primary winding should be about 2 2 ohm the secondary winding should be about 130 ohm otherwise it indicates the transformer has broken and should be replaced by a new If the transformer is normal then the high voltage capacitor should be checked Pull out the connecting plug of the capacitor and measure it with Rx1 grade of a multi meter the two rod of the multi meter connect the two polarity of the capacitor Whenthey just connected the reading of the multi meter should be zero then enlarge to nine mega ohm slowly Change the rod to different polarity the reading repeat from zero to 9 mega ohm FIG 5 5 it means the capacitor is normal If the indicator of the multi meter can t point out from zero to 9 mega ohm it indicates the high voltage capacitor has broken and should be replaced by a new one C FIG5 5 FIG5 6 12 SERVICE INFORMATION If it is normal between the two pole of the capacitor then the insulation between the capacitor pole and the cabinet FIG 5 6 should be checked If the resistance value between the capacitor pole and the cabinet is capacitor is normal Then check the earth of the magnetron s two filament to see whether they are short circuited FIG 5 7 If they are short circuited and the filament strikes the shell of the magnetron it indicates the magnetron has broken and should be replaced by a new same model one If there is no problem with the magn
9. 7 18 19 20 21 22 23 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 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 described in this manual before the oven is released to the owner E Amicrowave leakage check should be performed on each oven prior to release to the owner CAUTION Unlike other appliances the micr
10. CE 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 TESTCAUTIONS 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 cm2 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 brought 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 5 mW cm2 Always start measuring of an unknown field to assure safety for operating personnel from radiation leakage NECESSARY
11. CTING ANY HIGH VOLTAGE PARTS Magnetron H V Transformer H V Capacitor H V Cable Ass y H V Fuse 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 e Microwave energy leakage must not exceed the values prescribed below NOTE Leakage with the outer case removed less than 3 mW cm2 Leakage for a fully assembled oven Before the latch switch primary is interrupted with the door in a slightly opened position less than 1 mW cm2 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 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 SERVICE INFORMATION 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
12. ERMOSTAT 90 80 H 1100051158 EC20GBSK E35 THERMOSTAT 160 95 V 1100051159 EC20GBSK G01 HEATER COVER 1100051160 EC20GBSK G03 HEATER SHEATH T 1100051161 EC20GBSK G08 SUPPORTER HEATER 1100051162 22 EXPLODE CODE PARTS NAME amp SAP CODE EC20GBSK LO1 LATCH BOARD 1100051163 EC20GBSK 102 SWITCH LEVER 1100051164 EC20GBSK INTERLOCK MICROSWITC 1100051165 EC20GBSK LO4 MONITOR MICROSWITCH 1100051166 EC20GBSK LOS HARNESS MAIN 1100051167 EC20GBSK 502 SCREW ST 3 8PBHC 1100052599 EC20GBSK 503 SCREW ST 4 8 1100052592 EC20GBSK S04 SCREW ST 4 10 TBHC 1100052581 EC20GBSK 505 SCREW 4 12 PwBHC 1100052584 EC20GBSK 506 SCREW 4 20 1100052588 EC20GBSK 507 SCREW 4 8 1100052576 EC20GBSK sos SCREW CT 4 10 HWBHC 1100052581 EC20GBSK 511 SCREW CT4 10 1100052582 EC20GBSK 513 BOLT EC20GBSK 514 NUT M4 1100052579 EC20GBSK 515 NUT 5 1100052594 EC20GBSK S16 SCREW ST 4 10 TDB 1100052582 EC20GBSK S17 SCREW ST 3 10 WTHC 1100052596 EC20GBSK 521 SPRING WASHER R4 1 1100052578 EC20GBSK S22 SCREW R4 12 1100052584 EC20GBSK 523 SCREW R4 6 1100052593 EC20GBSK TOJ TRAY MOTOR 1100051168 EC20GBSK TOZ TURNTABLE SHAFT 1100051169 EC20GBSK RING ROTATING ASSY 1100051170 EC20GBSK 4 TRAY 1100051171 EC20GBSK wo1 FAN GUIDE 1100051172 EC20GBSK wo2 FAN 1100051173 EC20GBSK 1100051174 EC20GBSK 201 H
13. HE UNIT IS SERVICED FOR ANY REASON e SURE THE WIRE LEADS ARE IN THE CORRECT POSITION e WHEN REMOVING THE WIRE LEADS FROM THE PARTS BE SURE TO GRASP THE CONNECTOR THE WIRES 16 SERVICE INFORMATION COMMON BREAKDOWN AND MEANS OF REPAIRING PHENOMENON CAUSE REPAIRING MEANS 1 fuse broken 1 Change a new fuse 2 The primary and secondary winding of the 2 Change a new transformer are short circuited transformer 1 When starting the 3 The earthing or the polarity of the capacitor is 3 Change new capacitor oven the lamp is not on punctured 4 Change a new pilot the turntable tray can switch rotate and the food 5 The interlock switch hasnsed 5 Change a new interlock be heated 6 The power plug and the socket are not in good switch connection 6 Adust the connection or 7 The door hook broken replace it by a new one 7 Change a new book 2 When starting 1 The primary and secondary winding the 1 Change a new oven the lamp is on the filament of the transformer are open circuited transformer turntable rotating the fan 2 The magnetron filament is open circuited the 2 Change the magnetron cycling but the food magnetic steel of the magnetron broken or the 3 Change the time power be heated magnetron is air leaking distributor or the micro 3 Time and power distributor broken Switch 4 The plugs of the magnetron of the capacitor 4 F
14. OLDER H V C 1100051175 EC20GBSK 722 SPONGE 1100051176 EC20GBSK 224 OUT CASE 1100051177 29 NORTH ZONE DELHI 011 39996369 GURGAON 0124 4201250 54 CHANDIGARH 0172 5074588 JAIPUR 0141 4085010 KARNAL 9254304822 LUDHIANA 0161 5032738 39 740 741 AGRA 0562 3201515 LUCKNOW 0522 4017315 DEHRADUN 0135 3248805 JODHPUR 0141 3268934 3248934 JALANDHAR 0181 5020297 VARANASI 0542 2363383 JAMMU 0191 2431759 GHAZIABAD 0120 4162000 SOUTH ZONE CHENNAI 044 26209378 2629379 BANGALORE 080 32941177 66 44 COCHIN 0484 3113155 66 77 HYDERABAD 040 32449623 32446200 COIMBATORE 0422 2333146 MADURAI 0452 3268866 27 VIJAYAWADA 0866 3248833 55 VIZAG 0891 2732037 HUBLI 0836 3246644 55 4250971 MANGALORE 0824 2491 388 CALICUT 0495 3233511 22 WARANGAL 0870 3293300 11 EAST ZONE KOLKATA 033 44031400 BHUBANESHWAR 0674 2597281 RANCHI 0651 2340362 ASANSOL 0341 2221017 GUWAHATI 9954746944 PATNA 0612 6457897 WEST ZONE AHMEDABAD 079 26400418 26408976 AURANGABAD 0240 2471201 BHOPAL 0755 3206631 BARODA 0265 2359084 3249443 SURAT 0261 2461569 RAJKOT 0281 2465041 GOA 0832 2462554 RAIPUR 0771 2445196 THANE 022 32162709 PUNE 020 24260329 489 INDORE 0731 2544537 MUMBAI 022 40584600 NAGPUR AKOLA 0712 2543079 JABALPUR 0761 3221556 NASHIK 0253 2582703 704 EO IER EO EC OO OECD EO EO OQ REIR EQ OE IEEE ERO EE REED EE HERES 4 Electrolux VIDEOCON INDUSTRIES LIMITED 14Km Stone Aura
15. Stand for microwave field strength F Stands for the microwave frequency Er Stands for relative dielectric constant of the heated matter tg Stands for loss angle tangent of the heated matter INSTALLATIONS BEFORE YOU BEGIN READ THE FOLLOWING INSTRUCTIONS COMPLETELY 1 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 2 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 3 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 4 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 5 Use microwave oven in an ambient temperature less than 104 F 40 C 6 Place the microwave oven on a sturdy and flat surface at least 10 cm 4 inches from the wall 7 Place the microwave oven as far away as possible from RADIO COMPUTER etc to prevent interference 10cm EARTHING INSTRUCTIONS This microwave ove
16. a new door 14 SERVICE INFORMATION 2 Means of repair when the oven can heat but the turntable glass can t move Firstly check whether the turntable holder is placed correctly If it is correct then pull out the power plug and take down the turntable combination measure the resistance value of the turntable motor with Rx1k grade of a multi meter If it is open circuited it indicates the turntable motor has broken and should be replaced by a new same model one If the resistance value is between 15 22k it indicates the turntable motor is normal then check the connecting shaft weave If the plastic that the shaft insert in has broken a new shaft weave should replace it 3 Repair when the oven can heat but the lamp is not on Pull out the power plug take down the outer case and discharge the capacitor Pull out the two terminal plugs of the lamp measure the two plugs of the lamp with the Rx100 grade of a multi meter If it is open circuited it indicates the lamp has broken and should be replaced by a same model one 4 Means of repair when the oven stop working after several minutes operating The phenomenon indicated the thermal cutout is playing its protective role and you should check whether the fan is working in normal Turn off the oven pull out the power plug take down the outer case discharge the capacitor then turn the fan with hand to see whether it is moving flexibly If not it indicates that the oil bearing of the fan m
17. akage d Hold the oven in your facility and instruct the owner not to use the unit until the oven has been brought into compliance 1 3 In the event that the oven operates with the door open The following procedures should be followed a Tell the user not to operate the oven b Hold the oven in your facility until it is investigated and repaired c Contact the manufacturer immediately 2 Interlock Assembly Replacement and Adjustment 2 1 If you suspect defective primary secondary or monitor interlock switches use your ohmmeter digital or analog type the check the electrical continuity 2 2 Make sure the power cord is pulled out and the high voltage capacitor is discharged before the electrical continuity check 2 3 Set the ohmmeter to Low Resistance range and connect both leads alligator clips to the switch terminals 2 4 Open the door and notice the meter reading The primary or secondary interlock switch should show an infinite resistance when the door is open Replace it when it is defective The monitor interlock should show a zero or near zero resistance when the door is open When the door is closed the readings will be opposite 2 5 If the oven has been received inoperative due to the failure of the monitored safety primary and or secondary interlock s you should replace all of the monitored safety interlock switched and the monitor switch 3 Door and Hinge Replacement and Adjustment 3 1 Pull the power cord from the
18. e is energized 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 sure that the magnetron gasket is properly installed around the dome of the tube whenever installing the magnetron FILAMENT ANTENNA COOLING FIN MAGNETRON CHASSIS GROUND MAGNETRON THE OVEN IS TO BE SERVICED ONLY BY PROPERLY QUALIFIED SERVICE PERSONNEL THE HEATING PRINCIPLE OF MICROWAVE Microwave is one kind of radio wave whose wave length is very short frequency is very high Therefore it is called ultrahigh frequency electromagnetic wave Microwave can heat food mainly result in the mutual affect of the food in the microwave field and microwave field itself Under the affect of microwave field the thermal effect mechanism produced from the mutual affect of the microwave and the food includes two aspects One is Dielectric loss of polar molecule the other is conductive loss of ion Usually food is constitute of organism plant and animal The organism is formed by all kinds of polar water molecule polar protein molecule and all sorts of saltion The center of gravity of the positive and negative charge in the molecule is not coincide In normal condition the molecule is in irregular order due to its thermal action thus the food do not appear polarity FIG 1 1a THE HEATING PRINCIPLE OF MICROWAVE Under the action o
19. e outer case disordered a little but abnormal if the oven the door disordered the door hook broken the door crooked or there are too much looseness between the door and the oven after the door is closed 2 Listening Listening to the voice of the oven operating and the noise of the fan after it conducted Minor noise cycling kala noise and shishi noise should be consider as normal But it is abnormal if the following noise occurred 1 Sound wenwen noise 2 Long time shishi noise 3 Strike voice like pipa pipa SPOT EXAMINING STEPS OF THE MICROWAVE OVEN 1 Examine the microwave insulating resistance Measure the insulating resistance with a multi meter or a mega ohmmeter The value should not less than 2 mega ohm Otherwise part examination should be taken at once Such as checking whether the motor the thermal cutout the transformer or the capacitor are electricity leaking 2 Examination of the resistance value of the microwave oven Close the door set the time the oven is at operating condition but the power plug haven t been plugged in measure the two feet L N of the power plug with Rx1 grade of a multimeter the resistance value should be about 22 ohm If open circuit occurred then you must check whether the 10 A fuse is broken the primary winding of the transformer is open circuit the thermal cutout is open circuit or not you must check whether the interlock device is put t
20. etron check the high voltage diode then Measure the diode with Rx10k grade of a multimeter the rod end of the multi meter connect the cathode of diode the rod end of the multi meter connect the anode of the diode FIG 5 8 The multi meter reading should be about 150 thousand ohm Then change the rod to different electrode FIG 5 9 the reading should be If the reading is very small and near to short circuit it indicates the high voltage diode has been punctured and should be replaced by a new one If high voltage diode is also normal then test the pilot switch FIG 5 10 Pull out the two plugs of the switch Measure it with the Rx1 grade of a multi meter the two rod connect the plug of the switch the resistance value should be Then press down the pilot switch with a screwdriver if the reading of the multi meter pointed to zero it indicates the pilot switch has broken and should replace it with a new same model one FIG 5 8 FIG5 10 FIG 5 9 13 SERVICE INFORMATION REPAIRING METHOD OF SEVERAL BREAKDOWN 1 Repair when there occurred large amounts microwave leakage There are many factors which may cause microwave leaking Following mentioned may be the main cause of microwave leakage 1 The door deformed the hinge loosed or damaged that caused the door can not close tightly 2 The door pressing cover or the embed piece damaged or come off 3 Obvious damage or uneven of the oven 4 There a
21. f outer electric field the positive end of the polar molecule trend to the negative electric field the negative end of polar molecule trend to the positive electric field and somewhat arrange in order through the direction of the electric field FIG 1 1c This phenomenon usually be called TORQUE POLARITY When the outer electric field apply for the opposite polarity the polar molecule then arrange an opposite direction order accordingly FIG 1 1b If the direction of the outer electric field changed repeatedly the polar molecule would repeatedly sway accordingly During the swaying it understands that the polar molecule would produce heat due to somewhat similar EE 7 908 H 1000001 100004 n 5 Figl 1 When the electric field is applied for ultrahigh frequent microwave field from the outside its direction would change tens billion times per second so do the molecule This kind of molecule swaying producing similar frictional heat from the interference and block of the action strength among the molecule and changed to microscopic microwave heating Microwave heating not only concerned the nature of the matter itself but also closely connected with the electric field strength and frequency When the frequency is low the molecule swaying rate and the acute degree ofthe mutual friction among the molecule is low and would produce much heat When the frequency is too high as the swing of the polar molecule is with rotating inertia it
22. hrough or all the plugs are connected well If short circuit occurred you should check whether the primary winding of the power transformer is short circuited or part short circuited 11 SERVICE INFORMATION 3 Examination of microwave leakage Measure the microwave leakage with a microwave leakage Measure Place a graduate of 275 water at the middle of the glass tray of the oven FIG 5 1 Close the door power set high time set to 3 minutes press the starting button to operate the oven After rectified the microwave leakage measure measure around the door crack those hole position of the window and the air vent at four sides of the oven with the probe of the measure When measure the moving speed of the probe should not exceed 2 5cm per second and the measuring direction should be the same with the outing direction of the microwave leakage FIG 5 2 When measuring the ultimate value of microwave leakage of all the measured position should not exceed 1 0 mili watt cm2 or should be considered as abnormal Probe scanning speed Less than 2 5 cm sec 1in sec 275ml Glass tray CES 2 SSS FIG 5 1 FIG 5 2 4 Examine when the oven at operating but the food can t be heated Pull out the power plug take off the outer case discharge the capacitor measure the resistance value of the primary winding and the secondary winding of the transformer with a multi meter FIG 5 3 and FIG
23. is applied to the high voltage RAY MER CO RELY transformer through V P C MONITOR RESISTOR MONITOR SWITCH SECONDARY SWITCH 5 Turntable rotates The fan motor rotates and cools the magnetron by blowing the air coming from the intake holes on the baseplate over the magnetron The air is also directed into the oven to exhaust the vapor in the oven through the upper plate Timer starts rotating 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 diode and charging of the high voltage capacitor The negative DC voltage is then applied to the filament of the magnetron WBEN THE DOOR IS OPENED DURING COOKING Both primary switch and secondary Switch open to cut off the primary POWER winding voltage to the high voltage M RELAY transformer to stop microwave oscillation Timer turntable and fan motor stop As the door is opened if the contact of primary switch fail to open the fuse opens due to the large current surge caused by the monitor switch activation which in turn stops magnetron oscillation SECONDARY SWITCH 00000 A XXX SERVI
24. ith the switch holder tightly then tighten the screw again and open and close the door repeatedly to check whether the door can operate flexibly whether the hook and the switch are in their normal position If it is not in position then adjust the door hook and the switch holder the loose between the door and the oven then measure the leakage with microwave leakage measure again If there still exist microwave leakage measure near the magnetron with the probe of the microwave leakage measure If the leakage is larger the oven should be turned off and check whether the 2 or 4 screws which fix the magnetron have been loosed if loosed twist them tightly with socket wrench If the screws are fixedly then the magnetron should be take down to check the copper filament weaved washer of the magnetron has been placed well or whether the wave guide housing coupling has been oxidized or have lacquer on it If do have scrape the oxidized layer or the lacquer off when fix the magnetron the copper filament weaved washer must be placed well the screws must be twist tightly Then turn on the oven and measure again until it complies with the requirement If the microwave leakage is larger at those hole position of the window board the oven should be turned off to inspect whether there are crack among them If several holes formed a crack it would enlarge the microwave leakage If that is the case it indicates the door has broken and should be replaced with
25. ix them loosed 3 The food 1 Thelamp broken 1 Change a new lamp heated but the lamp is 2 The plug fall off 2 Insert the plug again not on 4 The food 1 The turntable motor broken 1 Change the turntable heated but the turntable 2 The plug fall off motor tray is not rotating 3 Connecting shaft weave broken 2 Insert the plug securely 3 Change the weave 5 The oven can heat 1 The winding of the fan motor in open circuited 1 Change the fan motor within 2 3 minutes but 2 The fan falls off 2 Change the fan can not heat from the 3 The plug of the fan motor falls off 3 Insert the plug fourth minutes 4 The turntable shaft is griped with the motor 4 Overhauling them bearing 5 Repairing it 5 The cooling vent blocked 6 When starting the The high voltage diode was punctured Change a new diode oven it cant heat and with nwenweni noise 7 oven heat but with sound tshishie noise The iron core of the transformer loosed Change a new transformer 8 Large amount of 1 The door deformed 1 Mend the door microwave leakage 2 The door metal net cracked 2 Change the door 3 The gap of the door crack is too large 3 Adustthe gap 4 The welding point of the oven fall off 4 Change the oven 5 The screws which fix the magnetron loosed 5 Tighten the screws 6 The wave guide connection oxidized 6 Scrape the oxidized and 7 The magnetron copper filament washer is too
26. made the swing do not in line with the changing rhythm of the electric field because of the friction drag thus actually lowed the polar molecule swaying speed The friction dragging degree is concerning aboutthe magneto electric wave frequency polar molecule shape and the matter s sticky degree To different matter s molecule there are different special frequency zone Those ado absorb microwave energy from these zone are most capable to turn microwave energy to heat energy Apart from the above said action there is another action which is electric ion underthe action of microwave field actfiercely accompanied with the acceleration of electric field The positive ion transfer to the negative polarity of the field while the negative ion do opposite Accompanying with the changing electric field the electric ion changing accordingly During the transferring heat produced with the crash among the ion This kind of action take the main effect to those microwave heating of high salt molecule No matter itis the polar molecule swaying orthe ion transferring they both are turning the microwave energy which the heating matter got from the microwave field to hear energy From the analysis of theory we can draw such a conclusion that the power which a unit of volume matter absorbed from the microwave field as the following formula F Er tg Stands for the power the heated matter absorbed from the microwave field K Stands for a constant E
27. n 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 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 the plug which is marked with the letter N or colored black e 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 1 2 3 L Beas A A MAGNETRON M Vor a call Ax RD BR m m POWER SUPPLY m RD FILTER ASS Y Ive me LS O O B Cray E amp 3 CAPACITOR E
28. ngabad Paithan Road Chitegaon Dist Aurangabad 431105 Tel 91 2431 251501 FAX 91 2431 251554
29. otor has run off the oil and should take down the fan combination to repair the motor Loosen the two screws which fix the bearing out the shaft and the bearing and rinse them with kerosene ATTENTION The bearing can only be wiped with a silk which moistened with kerosene rather than be washed in the kerosene because there are felt on it If the felt are soaked with kerosene then the engine oil can not be sucked up After the bearing being cleaned the felt should be refueled fully with engine oil for when the oven is operating the engine oil empty into the oil bearing slowly Fix the bearing cover with two screws turn the fan around till it can move flexibly Than install them to the oven and plug in the two terminal plugs If the fan can move flexibly then the winding of the fan motor should be examined Measure the winding with Rx100 grade of a multi meter if it is open circuited it indicates the winding of the fan motor has broken and should be replaced by a new same model one 15 SERVICE INFORMATION MOTOR TEST PROCEDURE COMPONENTS TEST PROCEDURE RESULTS Fan Motor Measure the resistance Wire leads removed Ohm meter scale R 100 Normal Approx 47 0 or Several Turntable Motor Wire leads removed Measure the resistance Ohm meter scale R 1000 Normal Approx 3 2kQ Abnormal co or Several Q NOTE AMICROWAVE LEAKGE TEST MUST ALWAYS BE PERFORMED WHEN T
30. owave 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 a 2 wire extension cord during repair and use NEVER TOUCH any oven components or wiring during operation BEFORE TOUCHING any parts of the always remove the power plug from the outlet E 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 CAUTION E Remove your watches whenever working close to or replacing the Magnetron DO NOT touch any parts of the control panel circuit A resulting static electric discharge may damage this P C B NEVER operate the 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 devic
31. re filth between the door and the oven 5 The door and the oven are serious loosed after the door closed 6 The crack of the door shielding net cover Before repairing check whether the above listed point existed if not you can start the microwave oven Place a graduate of about 275ml water at the middle of the glass tray close the door time set at 3 minutes power at high makes the oven operating in normal Rectify the microwave leakage measure measure the amount of the microwave leakage around the oven with its probe If there are places which the leakage exceed the standard requirement then repair them accordingly If the leakage amount exceed 1 0 mW cm2 at the left door crack then pull out the power plug take down the outer case adjust the screws of the hinge to less the gap between the door and the oven Then measure again the leakage amount should less than 1 0 mW cm2 Generally it should be controlled below 0 8 mill watt cm2 with some allowance If the leakage occurred at the right door crack adjust the screws that fix the interlock holder and the hook If the leakage is on the larger side at the right above of the oven then adjust the upper screw Loosen out the screw push the door close to the oven to hook the door hook with the plastic parts then tighten the screw again If the leakage is larger at the right below then adjust the lower screw Loosen the screw push the door close to the oven to hook the door hook w
32. rmula P 4187 x T T 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 heat WATER LOAD TURNTABLE 10 SERVICE INFORMATION TROUBLE SHOOTING PROCEDURES Before overhauling a microwave oven you should judge the breakdown and the cause correctly then you can repair it with corresponding ways The overhauling must be proceed in order any hasty conclusion is not recommendable otherwise overworking would be done when repair The microwave oven may occur compound breakdown due to all kinds of different reasons thus when overhaul they all should be taken into consideration Special attention must be given to the microwave leakage and the electric insulation when examine because they may do harmful to the repairing staff MEANS OF THE BREAKDOWN EXAMINING How to examine a microwave oven with breakdown A better means which demonstrated in practical operating are through inspecting and listening On the basis of large amounts of perceptual knowledge you can judge and analysis the breakdown quickly and correctly 1 Inspection Inspect whether the oven shape is disordered and where is the disordered position if any It is normal if th
33. tighten the screws thin cause the wave guide opening not in good 7 Thick the copper filament earth washer 9 The door canrt open 1 After long time using the wear and the rust 1 Adust the hinge to rectify eaten enlarged the gap of the door shaft and the position of the door the shaft hole thus cause the door crooked 2 Change the hook 2 The door hook broken 10 The door release Wore aged after long time operating Overhaul it or renew it button fall off 11 Electricity leaking The earthing insulation resistances of all the motors or the transformer are less than 2 mega place then repair it or ohm change those damaged components Test where is the leaking 17 SERVICE INFORMATION IMPORTANT THINGS TO DO PRIOR TO CRITICAL PART SERVICING The following instructions are CRITICAL to the owner s safety Be sure to follow all the instructions Contact the manufacturer of distributor if you have any question 1 1 If the oven is operative prior to servicing a Microwave Leakage Test Microwave Emission Check should be performed prior to servicing the oven 1 2 in the event that any microwave oven found to have microwave emission level in excess of 1 mW cm2 The following procedures should be followed a Inform the distributor importer or manufacture the finding Record it in the logbooks well b Repair the unit at no cost to the owner c Investigate the oven and ascertain the cause of the excessive le
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