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5-14

(TROUBLE 3) Output power is low.

CONDITION

CHECK

RESULT

CAUSE

REMEDY

CONDITION

CHECK

RESULT

CAUSE

REMEDY

(TROUBLE 4) Grill.

CONDITION

CHECK

RESULT

CAUSE

REMEDY

No continuity.

No continuity.

Faulty thermostat.

replace.

Check the
continuity of the
thermostat.

Malfunction of the
timer switch.

replace.

Check the
continuity of the
timer switch
contacts.

1. Heater is not

operating.

Abnormal.

Normal.

Wire connection.

No continuity.

Thermostat
(Grill)

Malfunction the
thermostat.

Replace.

Malfunction the
heater.

Replace.

Heater.

Abnormal.

Normal.

Open or loosen.

Replace.

Output is low

Lower than 207V.

Decrease in power
source voltage
with load.

Suggest customer
contact local
electric power
utility co. or
qualified
electrician.

Check the 
power source
voltage
oscillating.

Measure the
magnetron’s
output(See test
procedure).

Normal

Less than 8.5˚C.

Faulty magnetron.

Replace.

Summary of Contents for NN-K105WB BPQ

Page 1: ... Frequency Magnetron Timer Outside Dimensions Cavity Dimensions Net Weight Shipping weight Specifications subject to change without notice 230 Volts AC 50 Hz Microwave 1100 Watts Grill 1000 Watts Combi 2050 Watts Single phase 3 wire grounded 800 Watts full microwave power IEC60705 2450 MHz 2M167B M47J1 0 60 min 455 W x 260 H x 325 D mm 315 W x 184 H x 294 D mm 11 5 kg approx 12 5 kg approx Specifi...

Page 2: ...r 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...

Page 3: ...ION 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 REPLACEMENT PARTS LISTS INFORMATION 6 0 Section A EXPLODED VIEW 6 1 Section A REPLACEMENT PARTS 7 1 Section B EXPLODED VIEW 8 1 Section B...

Page 4: ...commended for commercial purposes DESCRIPTION Microwave Power for Variable Cooking Power level High Max Medium 600W LOW 360W Defrost cDefrost Warm 90W Grill Grill Combi Combi Owner s manual Glass turntable Roller Rest Grill rack ITEM Control Complement Rating Label Location Accessories Back Side ...

Page 5: ...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 2 1 CAUTIONS Unlike other appliances the microwave oven is high voltage and high current equipment Though it is free from...

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: ...k System Window Door Screen Door Seal Grill rack Turntable Control Panel Oven Front Plate 4 1 OPERATING INSTRUCTIONS NN K105WB NN K105WB UK NN K135MB 1 POWER CONTROL KNOB Used to select power level for cooking 2 TIMER KNOB Used to set the cooking time ...

Page 8: ...RILL COOKING 1 Open the oven door place the food on the rack in the oven and close the oven door 2 Set the function 3 Set the timer to the desired cooking time The turntable begins to rotate cooking starts and the lamp is turned on At the end of the cooking time you will hear a ring sound and the lamp is turned off COMBI COOKING 1 Open the oven door place the food on the rack in the oven and close...

Page 9: ...venting 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 WHEN THE DOOR IS OPENED DURING COOKING Both primary switch and secondary switch open to cut off the primary wi...

Page 10: ...ervicing 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 MEASURING INSTRUMENTS TESTER VOLTS DC AC Ohmmeter Microwave survey meter Holaday HI 1500 HI 1501 Narda 8100 8200 Inch scale 600 cc non conductive material beaker gl...

Page 11: ...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 befween 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...

Page 12: ...pty vessel are at ambient 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 thd lowest position and the microwave power switched on The time T for the temperature of the wate...

Page 13: ...FORMER REMOVAL 1 Discharge the high voltage capacitor 2 Disconnect the leadwire from magnetron voltage transformer 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 g...

Page 14: ...t of 5 mW cm2 With a 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 J REMOVING THE TURNTABLE MOTOR 1 Remove the turntable 2 Remove the turntable shaft VERY CAREFULLY 3 Lay the unit down on its back 4 Remove the turntable motor cover The...

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

Page 16: ...er 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 conditio...

Page 17: ...OVEN HIGH VOLTAGE TRANSFORMER Wire leads removed MAGNETRON Wire leads removed Approx 1 4 ohm Approx 90 ohm Less than 1 ohm Normal Infinite Normal Infinite Normal Less than 1 ohm Normal Infinite PRIMARY TERMINAL SECONDARY WINDING FILAMENT WINDING TERMINAL COMPONENTS TEST PROCEDURE RESULTS 1 Measure the resistance Ohm meter scale Rx1 Primary winding Secondary winding Filament winding 2 Measure the r...

Page 18: ...nal Normal Momentarily indicates several ohms and then gradually returns to infinite Normal Infinite Normal Continuity Abnormal Infinite Normal Infinite Abnormal Continuity Measure the resistance Ohm meter scale Rx1000 Terminal to case Measure the continuity Forward Ohm meter scale Rx10000 Measure the continuity Reverse Ohm meter scale Rx10000 HIGH VOLTAGE DIODE NOTE Some inexpensive meters may in...

Page 19: ...fective switch and the fuse at the same time Replace just the fuse if the switches operate normally Normal Abnormal HEATER ELEMENT Wire leads removed Measure the resistance Multi meter scale Rx1 Measure the resistance with 500V 100M ohm insulation resistance meter NOTE Make sure heater is fully cooled when tested Normal Grill heater Approx 50 Ω at 20 30 C GRILL THERMOSTAT OVEN THERMOSTAT MAGNETRON...

Page 20: ... Normal Approx 100 200 kohm Abnormal Infinite or several ohm Note A is ON OFF switch B is power supply terminal of the timer motor C is defrost switch 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 A B A C 30 ...

Page 21: ...el to discharge any static charge built up in your body CONDITION Microwave oven 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 intensi...

Page 22: ...uity 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 1 Oven lamp does not turn on when the timer knob is pushed with door closed TROUBLE 2 Oven does not start even though the timer is set This fuse is a special type of fuse which is kept as spare part by the importer NOTE All ...

Page 23: ...e timer switch contacts 1 Heater is not operating Abnormal Normal Wire connection No continuity Thermostat Grill Malfunction the thermostat Replace Malfunction the heater Replace Heater Abnormal Normal Open or loosen Replace Output is low Lower than 207V Decrease in power source voltage with load Suggest customer contact local electric power utility co or qualified electrician Check the power sour...

Page 24: ...r resistor Replace Check the monitor resistor Abnormal Defective AC relay Replace Check the AC relay Abnormal Shorted H V diode Replace Check H V diode Abnormal Open the secondary winding of the high voltage transformer of faulty insulation of filament winding Replace Check H V transformer Abnormal Faulty capacitor Replace Check H V capacitor Abnormal Faulty magnetron Replace Magnetron TROUBLE 5 O...

Page 25: ...nges shown below please refer to Section A for spare parts For serial numbers greater than those below please refer to Section B for spare parts Model Serial No NN K135MBEPG L2600001 00085 L2600086 00796 L2600797 01196 L2601197 01337 L2601338 01366 NN K135MBWPG L3600001 00446 L3600447 02012 L2602013 02110 NN K105WBEPG L2600001 00736 L2600751 01133 L2600737 00750 L2601134 01704 L2601705 01708 L3600...

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