National NN-C781JF Service Manual Download Page 8

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V-16G-3C26-M

(W)

L-3C2-2

(W)

(BL)

L-2C2-2

(Y)

(R)

POWER RELAY 4 (RY4)

POWER RELAY 1 (RY1)

HIGH VOLTAGE INVERTER

SCHEMATIC DIAGRAM

- 8 -

NN-C781JF (ZPE, WNT)

WIRING DIAGRAM

NEW H.V.

CAUTION: H.V.

(S-5G0)

CAUTION
HIGH VOLTAGE AREA

AC 220V, 50Hz
AC 120V, 60Hz

SW0 SW1

DIGITAL PROGRAMMER CIRCUIT

STEAM SENSOR

TEMP SENSOR

INVERTER

MAGNETRON

2M261-M32G

THERMAL CUTOUT
(HEATER)

PRIMARY LATCH
SWITCH

SECONDARY LATCH
SWITCH

SHORT SWOTCH

GROUNDING

CHASSIS GROUND

FUSE

FAN MOTOR

CONVECTION
MOTOR

TURNTABLE MOTOR

OVEN LAMP

HEATER

POWER RELAY

SWITCHING POWER
SUPPLY

NEW H.V.

NOTE: Door closed.
Unit is not operating.
Ground
Chassis

Summary of Contents for NN-C781JF

Page 1: ...ensions Oven Cavity Dimensions Weight Output power IEC705 88 Test Procedure Specifications subject to change without notice Specifications Models 240V AC Single Phase 50Hz For KNQ Models 230V 240V AC...

Page 2: ...ed professional technicians Any attempt to service or repair the product or products dealt with in this service information by anyone else could result in serious injury or death 1 This product should...

Page 3: ...hazards High voltage may remain in circuit 2 Do not touch aluminum heat sink because it is very hot in high voltage and also very hot in high heat energy 3 Do not try to adjust or tamper with preset v...

Page 4: ...sed correctly a beep will be heard If a pad is pressed and no beep is heard the unit has not accepted the instruction The oven will beep twice between programmed stages At the end of any complete prog...

Page 5: ...day TOD by press ing appropriate pads 5 Press Clock pad TOD has now been resistered into the digital programmer circuit and will count up by minutes 2 Time Cooking for Two Stage OPERATION SCROLL DISP...

Page 6: ...esigned for home use Cooking will not operate during demonstration mode To set demonstration mode 1 Pour 150 15cc 4 5 1 2 ozs of room temperature water in a oven glassware or ceramic utensil Place the...

Page 7: ...5G0 CAUTION HIGH VOLTAGE AREA 10A FUSE 50Hz AC 220V 240V SW0 SW1 DIGITAL PROGRAMMER CIRCUIT STEAM SENSOR TEMP SENSOR INVERTER MAGNETRON 2M261 M32F THERMAL CUTOUT HEATER PRIMARY LATCH SWITCH SECONDARY...

Page 8: ...5G0 CAUTION HIGH VOLTAGE AREA AC 220V 50Hz AC 120V 60Hz SW0 SW1 DIGITAL PROGRAMMER CIRCUIT STEAM SENSOR TEMP SENSOR INVERTER MAGNETRON 2M261 M32G THERMAL CUTOUT HEATER PRIMARY LATCH SWITCH SECONDARY...

Page 9: ...wer 3 Turbo Defrost Control When this Auto Control feature is selected and the Start Pad is tapped A The digital programer circuit determines the power level and cooking time to complete cooking and i...

Page 10: ...eater may not be on during a heater on period if the preprogrammed oven temperature has been reached This is due to the fact that the oven is keeping the preprogrammed oven temperature constant so of...

Page 11: ...in the high voltage capacitors in the inverter power supply circuit board When replacing or checking parts remove the power plug from the outlet and short the Inverter output terminal of the magnetron...

Page 12: ...D TO RADIATION FROM THE MICROWAVE GENERATOR OR OTHER PARTS CONDUCTING MICROWAVE ENERGY IMPORTANT NOTICE 1 The following components have potentials above 250V while the appliance is operating h Magnetr...

Page 13: ...ACITORS REMOVE GROUND WIRE 08 180M 08 155M 08 150M 2 Digital Programmer Circuit DPC and membrane key board NOTE Be sure to ground any static electric charge built up on your body before handling the D...

Page 14: ...ing inverter and fan motor assembly 4 Unplug 3 connectors of inverter PCB 5 Remove 2 screws holding inverter PCB on to bracket NOTE Do not pull by lead wires but make sure to pull housing unless PCB o...

Page 15: ...E 9 Remove screws holding door E to door A assembly After replacement of the defective component parts of the door reassemble it and follow the instructions below for proper installation and adjustmen...

Page 16: ...E SURFACE OF LEAD WIRE WHITE SURFACE METAL SIDE TO DETECT STEAM FROM OVEN CAVITY 7 Steam sensor 1 Remove 1 screw holding steam sensor unit 2 Disconnect CN2 connector from digital programmer circuit bo...

Page 17: ...es from Inverter Power Supply U primary terminals B Connect test probes of ohm meter to the disconnected leads which were connected to Inverter Power Supply U C Test the continuity of short switch wit...

Page 18: ...e total amount of time it takes the microwave oven to switch to T2 time after the 10 second period 3 T2 time When the steam escapes from the cooking container placed in the oven the steam sensor detec...

Page 19: ...eat produced by the heater circuit and maintains the oven temperature the user had selected Normal room 10 C to 30 C The reading across the oven sensor thermistor should be within 100K ohm to 300K ohm...

Page 20: ...voltage will lower the magnetron output Take the temperature readings and heating time as accurately as possible A Fill the beaker with exactly one liter of tap water Stir the water using the thermom...

Page 21: ...2450MHz and use it following the manufacturer s recommended test procedure to assure correct results C When measuring the leakage always use the 2 inch 5cm spacer supplied with the probe D Tap the st...

Page 22: ...ammer circuit Terminals of power relay s and primary circuit of Digital Programmer Circuit When troubleshooting be cautious of possible electrical shock hazard 1 Oven stops in 3 seconds after pressing...

Page 23: ...efective DPC or power relay B RY 1 1 Open or loose wiring of secondary latch switch 2 Off alignment of secondary latch switch 3 Defective secondary latch switch 1 Decrease in power source voltage 2 Op...

Page 24: ...220 IC 220 RY 1 DISPLAY IC 1 IC 1 DISPLAY STEP 1 2 1 1 1 2 1 2 1 1 Trouble 4 Inverter circuit Inverter PCB Repair Procedures Warning for High Voltages 1 Unplug oven when removing outer cabinet 2 never...

Page 25: ...solder and use solder sucker iron to suck solder 2 Make sure to replace both Q701 and Q702 at a time with the same maker 3 Make sure to apply heat conduction grease between transistor and heat sink 4...

Page 26: ...nd CN703 2 Insert AC plug through the Amper meter with specified voltage NOTE Current will be changed by the input AC voltage 3 Operate the oven at High power setting for 1 minutes 4 Read input curren...

Page 27: ...2SA1309AQSTA AERGS215J452 AEVTZ6TLT102 AEDZ10ES2T1 AESZ12JS2T1 A609A4V00GP 1 1 1 2 1 1 2 1 2 1 1 2 1 2 1 1 1 1 1 1 2 1 1 1 4 1 1 CAPACITOR POLYESTER CAPACITOR FILM CAPACITOR FILM CAPACITOR CONNECTOR T...

Page 28: ...EXPLODED VIEW AND PARTS LIST 28 EXPLODED VIEW...

Page 29: ...ER AU HEATER AU SENSOR HEATER MOUNTING PLATE H V INVERTER U H V INVERTER U MICRO SWITCH MICRO SWITCH THERMAL CUTOUT MICRO SWITCH FUSE 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 4 1 2 1 1 1 1 1 1 2 1 1 1 1 1 1 1 1...

Page 30: ...MP SHADE CAUTION LABEL 1 1 1 1 1 1 1 1 1 1 1 1 1 1 4 1 4 1 1 1 1 1 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 18A 125V WNT EXCEPT WNT WNT EXCEPT ZPE WNT HNE MNQ YNQ YKE KKE KNQ TNE...

Page 31: ...PACER SCREW LEFT DOOR ARM DOOR KEY SPRING B DOOR A U Ref No Part No Part name Description Pcs Set Remarks D5 D3 D6 D6 D6 D6 D4 D8 D7 D1 D10 D9 D8 WIRING MATERIAL W1 W1 W2 W4 F030A5G00XN F030A5G00ZP F0...

Page 32: ...0XN F80025G00XN F82844J00XN F02459660AP 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 D P CIRCUIT D P CIRCUIT D P CIRCUIT D P CIRCUIT D P CIRCUIT D P CIRCUIT D P CIRCUIT D P CIRCUIT MEMBRANE SWITCH MEMBRANE SWITC...

Page 33: ...5E90ZP 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 INSTRUCTION MAUNAL INSTRUCTION MAUNAL INSTRUCTION MAUNAL INSTRUCTION MAUNAL EARTH CAUTION LABEL PACKING CASE PAPER PACKING CASE PAPER PACKING C...

Page 34: ...34 DIGITAL PROGRAMMER CIRCUIT SCHEMATIC DIAGRAM XN 104 10K OPEN 3 3K SHORT 1 5K 16K 6 2K 68K 30K OPEN IC1 JPR1 JPR2 YN TN MN HN SN KN ZP WN...

Page 35: ...IN 10 MIN SENSOR REHEAT VEGETABLES RICE CONGEE PORRIDGE FISH FROZEN FOOD COOK SOUP FRIED FOODS STEW VEG MEAT MIX CHICKEN MEAT PIECES BEEF LAMB PORK NN C781JF P 1 H 2 AK 3 AI 4 AJ 5 AF 6 AG 7 AH 8 AB 9...

Page 36: ...S1WBA60B BUZZER AL CHEM CAPACITOR AL CHEM CAPACITOR AL CHEM CAPACITOR AL CHEM CAPACITOR AL CHEM CAPACITOR AL CHEM CAPACITOR AL CHEM CAPACITOR CHIP CAPACITOR CHIP CAPACITOR CHIP CAPACITOR CHIP CAPACITO...

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