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PHENOMENON CAUSE 

REPAIRING MEANS 

1. When starting the 
oven, the lamp is not on, 
the turntable tray can’t 
rotate and the food can’t 
be heated 

8A fuse broken. 
The primary and secondary winding of the 
transformer are short – circuited. 
The earthing or the polarity of the polarity of 
the capacitor is punctured. 
The pilot switch can’t cut off. 
The interlock switch hasn’t closed. 
The power plug and the socket are not in 
good connection. 
The door hook broken. 

Change a new fuse. 
Change a new transformer. 
Change a new capacitor. 
Change a new pilot switch. 
Change a new interlock 
switch. 
Adjust the connection or   
    replace it by a new one. 
Change a new hook.   

  2.When  starting  the 
oven, the lamp is on, the 
turntable rotating, the fan 
cycling but the food can’t 
be heated.   

The primary and secondary winding, the 
filament of the transformer are open – 
circuit-ed. 
The magnetron filament is open – circuited, 
the magnetic steel of the magnetron broken 
or the magnetron is air leaking. 
Time and power distributor broken. 
The plugs of the magnetron or the capacitor 
loosed. 

 
 
Change a new transformer. 
Change the magnetron. 
Change the time power 
distributor or the 
micro-switch. 
Fix them.   

3. The food can be 
heated, but the lamp is 
not on   

The lamp broken. 
The plug falls off. 

Change a new lamp 
Insert the plug again 

4. The food can be 
heated but the turntable 
tray is not rotating. 

The turntable motor broken 
The plug fall off 
Connecting shaft weave broken   

Change the turntable motor 
Inset the plug securely 
Change the weave   

5. The oven can heat 
within 2-3 minutes, but 
can not heat from the 
fourth minutes   

The winding of the fan motor in 
open-circuited. 
The fan falls off 
The plug of the fan motor falls off   
The turnatable shaft is griped with the 
mo-tor bearin 
The cooling vent blocked 

 
1.Change the fan motor 
2.Change the fan 
3.Insert the plug 
4.Overhauling them 
5.Repairing it   

6. When starting the 
oven, it can’t heat, and 
with “wenwen” noise. 

The high voltage diode was punctured 

Change a new diode 

7. The oven can heat, but 
with sound “shishi” noise   

The iron core of the transformer loosed 

Change a new transformer 

8. Large amount of 
microwave leakage 

The door deformed 
The door metal net cracked 
The gap of the door crack is too large 
The welding point of the oven falls off 
The screws which fix the magnetron loosed 
The wave guide connection oxidized 
The magnetron copper filament washer is 
too thin cause the wave guide opening not 
in good earth.   

Mend the door 
Change the door 
Adjust the gap 
Change the oven 
Tighten the screws 
Scrape the oxidized and 
tighten the screws 
Thick the copper filament 
washer 

Summary of Contents for EM-W3000W

Page 1: ...EM W3000W Microwave Oven Service Manual REFERENCE NO SM GA0005 ...

Page 2: ...s List 4 1 THE HEATING PRINCIPLE OF MICROWAVE 5 2 THE STRUCTURE AND WORKING PRINCIPLE OF MICROWWAVE OVEN 6 2 1 HIGH VOLTAGE RECTIFYING CIRCUIT 6 2 2 MICROWAVE GENERATER 7 2 3 COOLING SYSTEM 7 2 4 ELECTRIC CONTROL SYSTEM 7 3 TYPICAL CIRCUIT ANALYASIS OF MICROWAVE OVEN 10 4 HOW TO ASSEMBLE AND DISASSEMBLE MICROWAVE OVEN COMPONENTS 11 4 1 THE CABINET 11 4 2 THE DOOR COMBINATION 12 4 3 THE CONTROL PAN...

Page 3: ...ave guide or transmission line and cavity for proper alignment integrity and connections D Any defective or misaligned 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 A microwave leakage check to verify compliance with the Federal ...

Page 4: ...3 E EM M W W3 30 00 00 0W W M Mi ic cr ro ow wa av ve e O Ov ve en n E Ex xp pl lo od de e D Dr ra aw wi in ng g ...

Page 5: ... 1 P15 GA 1000AP30P15 Shock proof rubber 2 B01 GA 1000AP30B01 Foam cushion 2 P16 GA 1000AP30P16 Air duct 1 B02 GA 1000AP30B02 Foam cushion 2 P17 GA 1000AP30P17 Wind baffle 1 B03 GA 1000AP30B03 Owner s manual 1 P18 GA 1000AP30P18 Bracket 1 B04 GA 1000AP30B04 Plastic bag 1 P19 GA 1000AP30P19 Fan blade 1 B05 GA 1000AP30B05 Plastic film 1 P20 GA 1000AP30P20 Fan shroud 1 B06 GA 1000AP30B06 Foam cushion...

Page 6: ...es 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 strength and frequency When the frequency is low the molecule swaying ...

Page 7: ...ng steadily from a too high temperature If something wrong with the cooling system cause the temperature too high the control system would cut off the power automatically to prevent microwave generator being damaged form the high temperature Now we d like to introduce the working principle of each part of the widely used model mechanical control and touch control microwave oven 2 2 1 1 H HI IG GH ...

Page 8: ...ld attached to the surface of the anode and would be harmful to the anode In order to reduce the surge voltage the filament of the magnetron must be connected as the FIG 2 3 shown In this figure when the anode current of the magnetron circulates the filament current should flow to the FA end from the lower end 2 2 3 3 C CO OO OL LI IN NG G S SY YS ST TE EM M In the working process of the microwave...

Page 9: ...he microwave oven would stop operating immediately Provided due to some man made or the appliance itself reasons when the door is open and the safety interlock switches S1 S2 are not automatically cut off due to the existence of the monitor switch S3 which is still at conducted condition the monitor switch would immediately make the 120V voltage short circuited and blow up the fuse and will never ...

Page 10: ...rowave theory it is a microwave resonant cavity that can contain many kinds of oscillating models simultaneously Microwave enters into the oven cavity through the wave guide and the coupling appliance and most of its energy is absorbed by the food after it is reflected in the cavity repeatedly those which haven t been absorbed will be reflect to the magnetron A good designed oven cavity should hav...

Page 11: ... FOURTHWAVE LENGTH IMPEDANCE CHANGER Although there is no connecting point from a mechanical point It is sealed at the seam from the point of electricity so it is called CURRENT RESISTANT Recently with the installation of noise filter in the current resistant trough the effect to restrain the microwave leakage include high subharmonic have been much improved 3 3 T TY YP PI IC CA AL L C CI IR RC CU...

Page 12: ...rmal cutout S6 S6 will be cut off immediately to cut off the power supply to the magnetron and the magnetron will stops working right away The PC board is cut off to prevent the magnetron from being damaged by overheating When the thermal cutout is cut off the magnetron motors and the lamp would stop working simultaneously Moreover the thermal cutout has the self resuming character when the temper...

Page 13: ...the doorframe from the doorplate FIG 4 2 10 Take off the hook spring with a pointed plier then the hook combination 11 Clamp the window plate with hand push it down according to the arrow direction and take it off To assemble the door combination see sketch 4 2 to 4 5 1 Apply proper silicon grease or lubricating grease on the mark of the hook first then fix the hook on the oven door and the spring...

Page 14: ...isassemble 1 Pull out the terminal plug of the time and power distributor 2 Take off the screw which fix the control panel with a screwdriver FIG 4 6 3 Take off the control panel To assemble 1 Place the two buckles under the control panel into the two rectangle holes under the oven as FIG 4 6 then make close of the control panel and the oven with being fixed with a screw Plug in the terminal plug ...

Page 15: ...ure Then put on the seat and the right base board make sure the screw hole are tallied then tighten the four screws for the high voltage winding is earthing here 2 Fix the transformer on the oven as FIG 4 10 tear off the protect paper of the rubber spacer set it between the transformer and the oven make sure the adhesive side is sticked on the oven 3 Plug in all the terminals of the transformer pr...

Page 16: ...1 and FIG 4 12 4 4 7 7 T TH HE E C CA AP PA AC CI IT TO OR R Firstly do as the 1 2 3 steps of Ⅲ of this part To disassemble 1 Pull the wires of the capacitor out 4 15 2 Loosen and take out the screw which fix the capacitor clip with a screwdriver and take out the clip and the capacitor 4 15 To assemble 1 Place the capacitor in the capacitor clip with the end which have three foot near the diode 4 ...

Page 17: ...n back 5 As the FIG 4 19 shown fix in the turntable shaft supporter the place in the roller ring and the glass tray as FIG 4 20 4 4 1 10 0 T TH HE E D DO OO OR R S SA AF FT TY Y I IN NT TE ER RL LO OC CK KS S Firstly do as the same with 1 2 3 steps of Ⅲ of this part Steps for dismantling 1 Pull out the terminal plugs of the interlock switch and the pilot switch 2 Loosen out the two screws which fi...

Page 18: ... terminal plug of the PC board 2 Loosen out the two screws which fix the control panel with a screwdriver FIG 4 6 3 Take off the control panel 4 Take off the three screws which fix the PC board as the FIG 4 22 5 Take off the range terminal plugs as FIG 4 24 shown that is press the two places according to the arrow direction at the figure while pull it up about 2mm then off the row plastic board 6 ...

Page 19: ... like Pipa pipa 5 5 2 2 S SP PO OT T E EX XA AM MI IN NI IN NG G S ST TE EP PS S O OF F T TH HE E M MI IC CR RO OW WA AV VE E O OV VE EN N 5 5 2 2 1 1 E EX XA AM MI IN NE E T TH HE E M MI IC CR RO OW WA AV VE E I IN NS SU UL LA AT TI IN NG G R RE ES SI IS ST TA AN NC CE E Measure the insulating resistance with a avometer or a megaohmmeter the value should not be less than 2 megaohms Otherwise part...

Page 20: ...t 3 4V FIG 5 5 If there is no voltage at all it indicates the transformer has broken and should be replaced by a new one If it is enough to 3 4V check the filament resistance of the magnetron measure the filament plug with the R 1 grade of a avometer FIG 5 6 If it is open circuited it indicates the magnetron has broken and should be replaced by a new one It is normal if the resistance very small T...

Page 21: ...ero to nine megaohms it indicates the high voltage capacitor has broken and should be replaced by a new one If it is normal between the two pole of the capacitor then the insulation between the capacitor pole and the cabinet should be measured with R 10K grade of an avometer The resistance value should be FIG 5 12 If it is short circuited or have a number reading it indicates that the capacitor ha...

Page 22: ...e oven then adjust the upper screw as FIG 5 15 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 as FIG 5 15 Loosen the screw push the door close to the oven to hook the door hook with the switch holder tightly then tighten the screw again and open an...

Page 23: ...r with two screws turn the fan around till it can move flexibly Then 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 R 100 grade of a avometer if it is open circuited it indicates the winding of the fan motor has broken and should be re placed by a new same model one 5 5 4 4 T TH ...

Page 24: ...e cause of the excessive leakage 4 Hold the oven in your facility and instruct the owner not to use the unil until the oven has 3 In the event that the oven operates with the door open The following procedures should be followed 1 Tell the user not to operate the oven 2 Hold the oven in your facility until it is investigated and repaired 3 Contact the manufacturer and CDRH FDA immediately 6 6 2 2 ...

Page 25: ...ime power distributor or the micro switch Fix them 3 The food can be heated but the lamp is not on The lamp broken The plug falls off Change a new lamp Insert the plug again 4 The food can be heated but the turntable tray is not rotating The turntable motor broken The plug fall off Connecting shaft weave broken Change the turntable motor Inset the plug securely Change the weave 5 The oven can heat...

Page 26: ...ul it or renew it 11 Electricity leaking The earthing insulation resistance of all the motors or the transformer are less than 2 megaohms Test where is the leaking place then repair it or change those damaged components S SP PE EC CI IF FI IC CA AT TI IO ON NS S Power Consumption 120V 60Hz 1450W Microwave Power Output 1000W Operation Frequency 2450MHz Outside Dimensions H W D 11 9 20 5 17 1 in Ove...

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