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MOP0408003S2

Microwave Oven

NN-A774SBEPG

NN-A734MBEPG

NN-A764WBEPG

NN-A764WBWPG

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! WARNING

This service information is designed for experienced repair technicians only and is not designed for use by the 
general public. It does not contain warnings or cautions to advise non-technical individuals of potential dangers 
in attempting to service a product. Products powered by electricity must be serviced or repaired only by expe-
rienced proffesional technicians. Any attempt to service or repair the product or products dealt with this service 
information by anyone else could result in serious injury or death.  

There are special components used in this equipment which are important for safety. These parts are marked 
by (!) in the schematic diagrams, circuit board diagrams, exploded views and replacement parts lists. It is 
essential that these critical parts are replaced with parts specified by the manufacturer, preventing shock, fire 
or other hazards. Do not modify the original design without permission from the manufacturer.

IMPORTANT SAFETY NOTICE

Summary of Contents for NN-A774SBEPG

Page 1: ... expe rienced proffesional technicians Any attempt to service or repair the product or products dealt with this service information by anyone else could result in serious injury or death There are special components used in this equipment which are important for safety These parts are marked by in the schematic diagrams circuit board diagrams exploded views and replacement parts lists It is essent...

Page 2: ...de dimensions 359mm W X 352mm D x 217mm H Weight 15Kg Specifications subject to change without notice WPG Power source 230 V AC Single Phase 50Hz Power requirements Microwave 1260W Grill 1360W Convection 1470W Combi 2150W Output IEC60705 Microwave 1000W Grill1300W Convection 1400W Microwave frequency 2450Mhz Timer 99 min 99 second Oven cavity size 27L Outside dimensions 510mm W x 477mm D X 304MM H...

Page 3: ...peration Sequence 9 8 Cautions to be Observed when Troubleshooting 11 9 Part Replacement Proceedure 14 10 Component Test Proceedure 17 11 Measurements and Adjustments 19 12 Troubleshooting Guide 20 13 Parts List 26 14 Exploded View 29 15 Door Assy 30 16 Escutcheon Base 32 17 Packing and Accesories 34 18 Trim Kit 35 19 Digital Programmer Circuit 36 ...

Page 4: ...Stand Yes Kg lb No Stage Cooking 1 Clock 24 h Word prompt French Dutch English German Italian Spanish Polish no lan guage Function WPG Model Microwave 4 Grill 1 Convection 17 Combi Yes Weight Reheat 1 Weight Cook 4 Weight Combination 9 Weight Defrost 2 Weight Crisp 0 Delay Stand Yes Kg lb No Stage Cooking 1 Clock 24 h Word prompt French German English Ital ian no language ...

Page 5: ...m Pads 13 Panacrunch Program Pads 14 Start Pad Press to start operating the oven If during cooking the door is opened or Stop Cancel Pad is pressed once Start Pad has to be pressed again to continue cooking 15 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 d...

Page 6: ...pair the inverter PCB this can be very dangerous Replace the high volt age inverter circuit as a complete unit Do not adjust or tamper with the pre set volume on the inverter board It is very dangerous to adjust this pre set without proper test equipment Do not operate the microwave oven when the inverter grounding plate and fixing screw is loose It is very dangerous to operate the inverter circui...

Page 7: ...t operated Y G BL BR 2 0mH 4700pF 4700pF 4700pF 4700pF AC230 240V 50Hz 75k W 75k W 2 2M W 2 2M W 2 0mH SW3 L MONITOR DEVICE MONITOR DEVICE TURN TABLE MOTOR TURN TABLE MOTOR MTT THERMAL CUT OUT THERMAL CUT OUT THERMAL CUT OUT OVEN OVEN MAGNETRON SW5 RY1 F M 1 CN3 3 4 CN4 1 3 SW4 CN5 CN6 P C B AU 2 2F F m 2 2F F m 16A P C B DU P C B DU 2 1 2 CN702 1 3 CN703 F FA MAGNETRON MAGNETRON 2M236 M42 3 2 1 C...

Page 8: ...HE COLOUR O THE CONNECTOR HOUSIN MA NETRON HI H OL TA E IN ER TER CAUTION HEAT SINK HOT LI E ER Y HI H OL TA E AND TEMPERATURE BR BR BR OR 1 C2 PRIMARY LATCH SWITCH TOP WH WH WH SECONDARY LATCH SWITCH OUTSIDE BOTTOM BR N YE YE SHORT SWITCH INSIDE BOTTOM YE BL POWER RELAY RY1 N 2 1 BL SYMBOL COLOUR BL BLUE BK BLACK BR BROWN WH WHITE YE YELLOW N NATURAL R RED R ...

Page 9: ...cally via the control signal from the digital programmer circuit Note After auto cooking if the oven temperature is over the predetermined temperature the fan motor rotates to cool the oven and its compo nents EPG MODEL Auto weight defrost Auto Weight Cook WPG MODEL Auto weight defrost Category 1st Touch weight Cooking time Defrost Small Pieces 300g 5 Min 40 Sec Defrost Big Piece 600g 7 Min 30 Sec...

Page 10: ...in 00 Sec 5 Rice 200g 14 Min 45 Sec 6 Rice Pudding 600g 4 Min 00 Sec 7 Roast Pork 1000g 36 Min 20 Sec 8 Roast Beef 700g 16 Min 25 Sec 9 Poultry 500g 16 Min 15 Sec 10 Frozen Chicken Pieces 500g 23 Min 50 Sec 11 Jacket Potatoes 500g 14 Min 00 Sec 12 Fresh Lasagne Gratin 1000g 20 Min 20 Sec 13 Frozen Pizza 300g 12 Min 30 Sec 14 Frozen Potato products 300g 17 Min 00 Sec ...

Page 11: ...uminium heat sink is also energized with high voltage never touch this heat sink when the micro wave oven is plugged into the mains outlet The collec tor of the power device IGBT is directly connected to the aluminium heat sink The aluminium heat sink becomes very hot when the inverter circuit operates Never touch this heat sink during operation and allow time for it to cool down before servicing ...

Page 12: ...atch switch when the 10A 250V fuse is blown due to the operation of the short switch It is also important to change the power relay 1 RY1 when the continuity test shows shorted contacts 1 This is mandatory Refer to adjustments and meas urements for the location of these switches 2 When replacing the fuse confirm that it has the appropriate rating for these models 3 When replacing faulty switches b...

Page 13: ...n reach more than 5mW cm3 After repair or replac ing parts it is very important to check if the magnetron and the door hinges are correctly fixed 8 7 Sharp edges Please use caution when unpacking installing or mov ing the unit as some exposed edges may be sharp to touch and cause injury if not handled with care ...

Page 14: ...rge the high voltage capacitors 2 Remove 2 screws holding the tie bar 3 Unplug the H V Lead wires from the magnetron 4 Remove the 1 screw holding the earth wire to the magnetron 5 Remove the connector CN701 and CN702 from the inverter PCB figure 8 6 Remove the 2 screws holding the inverter support base to the oven chassis 7 Carefully remove the inverter circuit board and sup port base from the ove...

Page 15: ...ote Ground your body to discharge static charges before handling the DPC 1 Carefully remove all solder from the terminal pins of the low voltage transformer power relays using a 30W soldering iron and a solder sucker 2 With all of the terminal pins cleaned and separated from the DPC contacts remove the defective trans former power relays and install the new compo nents making sure that the termina...

Page 16: ... between the door and microwave oven 3 Perform the microwave leakage test figure 11Disassembly of the door figure 12Adjusting the door hinge 9 7 Turntable Motor 1 Remove the motor cover by breaking it off at the 8 spots indicated by the arrows 2 Disconnect the two lead wires connected to the turntable motor 3 Remove the 2 screws holding the turntable motor Note After breaking off the motor cover m...

Page 17: ...r to these leads 3 Test the continuity of the short switch with the door open and the door closed using a ohm meter set to the lowest resistance scale 10 3 Magnetron Continuity checks can only indicate an open filament or a shorted magnetron To diagnose an open filament or shorted magnetron 1 Dissconnect the high voltage lead wires from the magnetron input terminals 2 Check the continuity across t...

Page 18: ... tron on to determine if the inverter power supply is still functioning HEAT SINK RECTIFIER BRIDGE CHOKE COIL SAND BAR RESISTOR CURRENT TRANSFORMER HIGH VOLTAGE TRANSFORMER PRESET VOLUME 4 DO NOT ADJUST FILM CAPACITORS HIGH VOLTAGE DIODES HIGH VOLTAGE CAPACITORS CN 703 CN 702 CN 701 CONTROL BOARD WITH CUSTOM IC PHOTOCOUPLER DANGER HIGH VOLTAGE AND HIGH TEMPERATURE HOT LIVE HEAT SINK HIGH VOLTAGE R...

Page 19: ...ted Completely tighten the screws holding the door hook assembly to the oven assembly 4 Reconnect the short switch primary switch and sec ondary latch switches and check the continuity of the monitor circuit and latch switches by following the component test procedures on 11 2 Measurement of microwave output The output power of the magnetron can be determined by performing the IEC standard test Ho...

Page 20: ...y of these components when both legs are soldered into the board may result in a false reading or damage to your meter 6 When disconnecting a plastic connector from a terminal you must hold the plastic connector and not the lead wire otherwise the lead wire may become open circuit 7 Do not touch components on the digital programmer circuit this circuit is sensitive to static electricity 8 When wor...

Page 21: ...t including the mag netron filament circuit NOTE A large contact resistance lowers the magnetron filament volt age reducing the magnetron output or causing intermittent operation 3 Defective high voltage component Inverter circuit or Magnetron 4 Open or loose wiring of power relay RY1 5 Defective primary latch switch 6 Defective power relay RY1 or DPC AU or DPC DU Adjust door and latch switches Ch...

Page 22: ...ere is no microwave oscil lation Symptom Cause Correction 1 Microwave output is low Oven takes a long time to cook food 1 Decrease in power source volt age 2 Open or loose wiring of magne tron filament circuit causing inter mittent oscillation 3 Ageing of magnetron Consult electrician Refer to output test procedures Change magnetron 2 Loud Buzzing noise can be heard 1 Loose fan or fan motor 3 Turn...

Page 23: ...ot oscillate H97 H98 appears in the display window Check magnetron filament continuity Check Inverter input AC voltages at CN702 Check Inverter control signal at CN701 Pin 1 and 2 Magnetron DPC board Power relay Loose relay wiring Latch switch DPC board H V Inverter NOTE DANGER HIGH VOLTAGE Open 0V 0V Unplug CN702 and test for 3 VAC acorss the lead wire connector AC 240V Approx AC 3V Unplug CN702 ...

Page 24: ...V line Abnormal 0V IC10 Normal 12V Step 3 3 IC 1 pin 73 Emitter of Q10 Abnormal ZB10 Q10 Ribbon cable Normal 5V Step 4 4 IC 1 pin 27 pin 15 of IC220 Abnormal IC 220 Normal IC1 CX1 NOTE The procedure for repairing the fuse pattern on the DPC is as follows 1 Fuse pattern PF2 open circuit a Remove the jumper wire PF2 b Move the jumper wire PF3 into the postion of PF2 and solder inplace Replace the DP...

Page 25: ...rom the following test 1 Unplug CN702 connec tor and measure the voltage between the terminlas Abnormal 1 Latch switch 2 DPC Power relay Normal Step 2 2 Unplug CN703 connec tor and measure the voltage at Pin 1 Abnormal DPC Normal 1 Magnetron 2 Inverter circuit Diode Transistor Digital transistor A C C C C B B E E E E B B A K K Forward Forward Forward Forward Reverse Reverse Reverse Reverse A K B E...

Page 26: ... 17 XTWANE 4 8BN Screws 3 18 XTBANE 4 8BN Screws 2 19 E66794V00BP Heater Cover A 1 20 E630G8000BP Heater Unit 1 21 E22394V00BP Circulation Fan 1 22 E41634V00BP Fan Spacer C 1 23 XNG4EVSL Nut 1 24 E64174V00BP Heater Bracket A 1 25 XTWANE 4 8BN Screw 1 26 E00069000EP Warning Label 1 27 E10594V00BP Back Plate Cover B 1 28 XTWANE 4 8BN Screws 2 29 E22594V00BP Adiabatic Material D 1 30 E030A6R10BP Lead...

Page 27: ...4MB 70 XTW 3 6B Screws 2 71 E63268960JP Turntable Motor 1 72 E01507870EP Outer Panel Warning Label 1 EPG Models 72 E01505870GS Outer Panel Warning Label 1 WPG Model 73 XTWA 4 12CF Screw 1 74 XTWA 4 12DF Screw 1 75 E30074L00GP Lower Hinge 1 76 AEE2177 F80 Pulley Shaft Washer 1 77 E21315870GP Pulley Shaft 1 78 XST4 W5V Screw 1 79 E20554L00GS Cover A 1 80 E30064N30BP Upper Hinge 1 81 XTWA 4 12CF Scre...

Page 28: ...28 97 E67579000BP Heater bracket D 1 98 E22784V00SGP Upper Heater Cover 1 99 E00064080BP Warning Label 1 Ref No Part No Part Description Comments ...

Page 29: ...29 14 Exploded View ...

Page 30: ...rder door C as this part may become damaged during disassembly Ref no Part Number Part name description Qty Remarks D1 E302A6R10SEP DOOR A ASSEMBLY 1 A774SB D2 E30214000AP DOOR KEY SPRING 1 D3 E30184L00GS DOOR KEY 1 D4 E302K6R00BP DOOR E ASSEMBLY 1 D5 E30854V00BP DOOR C 1 ...

Page 31: ...may become damaged during disassembly Ref no Part Number Part name description Qty Remarks D1 E302A6R10NBP DOOR A ASSEMBLY 1 A734MB D1 E302A6R10HBP DOOR A ASSEMBLY 1 A764WB D2 E30214000AP DOOR KEY SPRING 1 D3 E30184L00GS DOOR KEY 1 D4 E302K6R00BP DOOR E ASSEMBLY 1 D5 E30854V00BP DOOR C 1 ...

Page 32: ... E5 E81276R00SBP Escutcheon Backplate 1 E6 E603L6R10EP PCB A U 1 E7 E60704V00SBP Insulation Sheet 1 E8 E82564V00SBP Door Opening Lever 1 E9 E603Y6R00BP PCB D U 1 E10 E80874L00SGS Earth Spring 1 E11 E81896R00SBP Display Window 1 E13 E00076R10SEP Nameplate 1 A774SB Panasonic NN A 813A g AU TO SE NS OR AU TO g Mi cro po we r Gr ill 1 2 3 Co nv ec tio n Tu rbo Ba ke Co mb ina tio n CHAOS DE FR OS T E1...

Page 33: ...or Opening Button 1 A764WB E1 E80726R00NBP Door Opening Button 1 A734MB E2 E80378A0AG Door Opening Spring 1 E3 E83376R10HEP Escutcheon Sheet 1 A764WBEPG A734MB E3 E83376R10HSP Escutcheon Sheet 1 A764WBWPG E4 E80346R00HBP Escutcheon Base 1 A764WB E4 E80346R00NBP Escutcheon Base 1 A734MB E5 E80246R10HEP Operation Buttons 1 E6 E81276R00BP Back Plate 1 E7 E603L6R10EP PCB A U 1 A764WBEPG A734MBEPG E7 E...

Page 34: ...P Service Centre List 1 P6 E00036R10EP Operating Instruction 1 EPG Models P6 E00036R10WP Operating Instruction 1 WPG Model P7 E000B6R10EP Cook Book 1 EPG Models P7 E000B6R10EP Cook Book 1 WPG Model P8 E02146A60KT Foam Sheet 1 P9 E06014N30BP Glass Tray 1 P10 E06015020VP Enamel Tray 1 EPG Models only P11 E060V8020BP Wire Rack med 1 P12 E060V6520UP Wire Rack 1 P13 E01084V40UP Tray Packing 1 P14 E0102...

Page 35: ...35 P17 EE02146700BP Door Sheet 1 P18 E01109010GS Vinyl Bag 1 Ref No Part No Part Name Description Qty Remarks ...

Page 36: ...Top and Bottom Strip ref 1 Qty Left and Right Strip ref 2 Qty Remarks NN TKA70AB E1603A510ABP 2 E1601A510ABP 2 A714AB NN TKA70MB E1603A510NBP 2 E1601A510NBP 2 A734MB NN TKA70WB E1603A510HBP 2 E1601A510HBP 2 A74WB E000QA820BP Installation Guide ...

Page 37: ...37 19 Digital Programmer Circuit ...

Page 38: ...38 ...

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