Panasonic NN-E271WM, Service Manual

Page 1: ...notice 1 250 Watts 5 A Single phase 3 wire grounded 2 450 MHz 0 99 min 90 sec 4 W x H x 340 D mm 11kg approx 2M219J Model No Panasonic Corporation 201 Unauthorized copying and distribution is a violation of law NN E271WM NN E281BM White 4 Volts AC 50 Hz 13 kg approx Order No H A D1110013C E Europe 20L Black 230 240 800 Watts full microwave power IEC60705 43 258 306 W x 215 H x 308 D mm 1 ...

Page 2: ... 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 owne...

Page 3: ... 2 SCHEMATIC DIAGRAM 4 3 CIRCUIT DESCRIPTION 4 4 SERVICE INFORMATION 5 1 TOOLS AND MEASURING INSTRUMENTS 5 1 MICROWAVE LEAKAGE TEST 5 1 MEASUREMENT OF MICROWAVE POWER OUTPUT 5 3 DISASSEMBLY AND ADJUSTMENT 5 3 INTERLOCK CONTINUITY TEST 5 7 COMPONENT TEST PROCEDURE 5 8 TROUBLE SHOOTING 5 12 EXPLODED VIEW 6 1 REPLACEMENT PARTS LIST 7 1 SCHEMATIC DIAGRAM OF P C B 8 1 CONTENTS ...

Page 4: ... not recommended for commercial purposes DESCRIPTION Microwave Power for Variable Cooking Power level ITEM Control Complement Rating Label Location Accessories Glass Tray Ro R ller ing Instruction manual Inside 270 Watts 200 Watts High Defrost Medium Low Warm 800 Watts 700 Watts 520 Watts ...

Page 5: ...tron 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 2 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 du...

Page 6: ...lat surface at least 10 cm 4 inches from the wall 7 Place the microwave oven as far away as possible from TV RADIO COMPUTER etc to prevent interference 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 As the colors of the wire...

Page 7: ...o Weight Cook Programs 6 Auto Weight Defrost Pad 7 Timer Clock Pad 8 Weight Selection Pads 9 Stop Cancel Pad Before Cooking one press clears your instructions During Cooking one press temporarily stops the cooking program Another press cancels all your instructions and the time of day will appear in the display 10 Start Pad 11 Door Release Pad The Design of your control panel may vary from the pan...

Page 8: ...LD LOCK Press start pad three times L appear in the display TO CANCEL CHILD LOCK Press stop cancel pad three times L disappears 4 2 Stop Cancel Clock Set the time by pressing Stop Cancel Desired defrost Desired Start Stop Cancel Desired cooking time Desired cooking power Start 2 STAGE 3 MICROWAVE COOKING 4 MULTI STAGE MICROWAVE 5 AUTO WEIGHT DEFROST time pads program weight Stop Cancel Desired Des...

Page 9: ...oltage capacitor The negative 4000 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 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 windi...

Page 10: ...hich 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 5cm spacer supplied with the probe Operate the oven at its maximum output Measure the microwave radiation using and electromagnetic radi...

Page 11: ...e 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 t...

Page 12: ...ely 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 thd 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 temperat...

Page 13: ...gh voltage capacitor 2 Disconnect the leadwire from magnetron high voltage transformer and capacitor 3 Remove the screw holding the high voltage transformer to the baseplate Remove door Assembly Remove door Assembly to the Cavity Ass y 2 Remove two screws holding the Hinge F 1 Discharge the high voltage capacitor 2 Disconnect the leadwire from fan motor noise filter and high voltage capacitor 3 Re...

Page 14: ...t the leadwire from the turntable motor terminals 6 Remove the screw securing the turntable motor to the oven cavity ASS Y 7 After rep 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 Waveguide Magnetron Gasket Magnetron Dome Waveguide Bracket Magnetron 2 W...

Page 15: ... 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 less than 0 5 mm 1 64 inch Don t push the door release button while making adjustment Make sure that the lat...

Page 16: ...n 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 Th...

Page 17: ...EDURE RESULTS HIGH VOLTAGE TRANSFORMER Wire leads removed MAGNETRON Wire leads removed 1 Measure the resistance Ohm meter scale Rx1 Primary winding Secondary winding Filament winding 2 Measure the resistance Ohm meter scale Rx1000 Primary winding to ground Filament winding to ground 1 Measure the resistance Ohm meter scale Rx1 Filament terminal 2 Measure the resistance Ohm meter scale Rx1000 Filam...

Page 18: ...x10000 Measure the continuity Reverse Ohm meter scale Rx10000 Normal Momentarily indicates several ohms and then gradually returns to Normal Normal Abnormal Continuity 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 Antenna Gasket Chassis Filament 10M ohms NOTE Some inexpensive meters may indicate infi...

Page 19: ...e primary the secondary and the monitor switches H V D and H V C before replacing the fuse If the fuse is blown by improper switch operation replace the defective switch and the fuse at the same time Replace just the fuse if the switches operate normally Check for P C B connector Normal Abnormal Cooking Start OFF Below specified temperature specified temperature Above L V Transformer of P C B Disc...

Page 20: ...e resistance Ohm meter scale R x 1000 Normal Abnormal or several Ω Normal Approx 100 200K Abnormal or several Ω NOTE A 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 00 500 1 Ω Ω ...

Page 21: ... does not work Inserting many plug into one plug outlet and using them at the same time causes overloading Microwave oven plug is not inserted tightly Output power is too low Low AC input voltage Food temperature is too low Using metallic ware and allowing it to touch the oven wall Sparks occurring Inconsistent intensity of microwave by their characteristics 1 Wrap the thinner part with aluminum f...

Page 22: ...ing cooking cycle 11 Display time of day does not reappear when cooking is finished 12 Beep sound is not heard when correct key is touched 5 13 TROUBLE 1 The following visual conditions indicate a probable defective control circuit CONDITION CHECK RESULT CAUSE REMEDY 1 No input can be programmed Continuity No continuity Everything works as specified Still have trouble Defective PCB assembly Replac...

Page 23: ...ch with door closed Check continuity of primary switch with door opened Disconnect one side of the wire lead connected from transformer to the high voltage capacitor and operate the unit Replace fuse TROUBLE 2 Oven does not operate at all Display window does not display any figures and no input is accepted NOTE All these switches must be replaced at the same time Refer to page 5 6 5 7 2 Fuse does ...

Page 24: ...k continuity of secondary switch with door closed Check fan motor Check oven lamp Abnormal Abnormal Normal Defective fan motor Defective oven lamp Replace fan motor Replace oven lamp Loose connection Connection then tightly CONDITION CHECK RESULT CAUSE REMEDY Output is low Lower than 90 of rating voltage Normal Normal Abnormal Abnormal Measure the output power Disconnect the wire leads from relay ...

Page 25: ...high voltage transformer Check H V transformer normal normal Abnormal Defective high voltage Diode Replace high voltage Diode Check H V diode Abnormal Defective high voltage capacitor Replace high voltage capacitor Check H V capacitor Abnormal Defective magnetron Replace magnetron Check Magnetron normal Abnormal Defective Protector Diode Replace Protector Diode Check Protector Diode TROUBLE 5 No m...

Page 26: ...e set power level Operates properly on HIGH CONDITION CHECK RESULT CAUSE REMEDY Output is full when you set lower power level Abnormal Disconnect the wire leads from relay 2 and check continuity relay 2 Operate the unit Defective P C B assembly Replace P C B assembly ...

Page 27: ...P NO Printed in China 11 Jun 20 ...