NN-A574SBBTQ NN-A554WBBTQ NN-A524MBBTQ
Contents
1. figure 12 Adjusting the door hinge 9 7 Turntable Motor 1 Remove the motor cover by breaking it off at the 8 spots indicated by the arrows Disconnect the two lead wires connected to the turntable motor Remove the 2 screws holding the turntable motor 2 9 Note After breaking off the motor cover make sure no sharp edges are exposed by trimming off the edges or bending them inside Note To secure the motor cover use a 4 x 6 screw figure 13 Removing the turntable motor cover figure 14 Removing the two screws fixing the turntable motor 9 8 Pulley Mechanism 1 Remove the Pulley Belt and Heater Hood 2 Remove Pulley A by releasing the nut and removing the washer 3 Remove the Thermistor screw and re position the thermistor cable so as not to interfere 4 Remove the screw securing the Motor Bracket and manouvre the fan cover from its housing 10 Component Test Procedure Caution e The inverter circuit operates at high voltages e Never attempt to measure the high voltage on the inverter circuit e Before touching any oven components or wiring always unplug the oven from its power source and discharge the high voltage capacitors 10 1 Primary latch switch secondary latch switch and power relay B interlocks 1 Unplug the lead wires from the contact terminals of RY1 check the continuity across these terminals using an ohm met2. Oven does not accept key input Program Shorted push button on DPC AU Defective DPC AU Refer to operation procedure Refer to DPC troubleshooting Oven lamp and turntable motor turn on when the microwave oven is plugged in with the door closed 1 2 3 1 Key input is not in sequence 2 3 1 Maladjusted or loose wiring of secondary latch switch 2 Defective secondary latch switch Adjust door and latch switches Timer starts to countdown but no microwave oscillation Ha Maladjusted latch switches 2 Open or loose connection of high voltage circuit 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 Check high voltage components according to the component test procedure 12 2 Troubleshooting fuse blown Symptom Cause Correction No display and no operation at all 10A Fuse is Blown 1 Shorted lead wire harness 2 Defective primary latch switch NOTE 1 3 Defective short switch NOTE 1 4 Defective Inverter power supply Refer to inverter circuit test pro cedure o
3. Do not attempt to measure the voltages in the microwave oven high voltage circuit Always discharge the high voltage capacitors on the inverter circuit board before troubleshooting When checking the continuity of the components on the H V Inverter circuit unsolder and remove one leg of the component from circuit board Checking the continuity of these components when both legs are soldered into the board may result in a false reading or damage to your meter 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 Do not touch components on the digital programmer circuit this circuit is sensitive to static electricity When working with the digital programmer board ensure your body is connected to ground to discharge any static charge 240 VAC is present on the digital programmer circuit Terminals of the power relays and the primary circuit of the low voltage transformer When troubleshooting be cautious of possible electric shock To ensure the complaint is not due to operator error check the operation of the oven by following the procedures explained in the operating instruction book 18 12 1 Troubleshooting no operation Symptom Oven is dead Fuse is OK No display and no operation at all Cause Open or loose lead wire harness Open low voltage transformer Defective DPC AU or DPC DU Correction
4. 3 Remove the membrane assembly by pushing from the inside of the base and then peeling it away from the outside surface NOTE 1 When installing a new escutcheon key board make sure that the surface of the escutcheon base is cleared avoiding problems such as shorted contacts and uneven surfaces 2 When replacing a stainless aluminium escutcheon assembly ensure that the stainless facia is earthed to the escutcheon back plate via the earth spring figure 9 Removal of DPC AU and DPC DU 9 4 Low voltage transformer and or power relays RY1 Note 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 terminal pins are inserted completely Carefully re solder all terminal contacts carefully Note Do not use a soldering iron of more than 30 watts on DPC contacts 9 5 Fan Motor 1 Remove 2 screws to remove the tie bar 2 Disconnect the 2 lead wires from the fan motor ter minals Disconnect all lead wires from the noise filter Remove the noise filter Remove 2 screws to remove cover B Remove 2
5. e Do not touch the aluminium heat sink as it is part of the high voltage circuit and becomes very hot e Do not attempt to repair the inverter PCB this can be very dangerous Replace the high volt age inverter circuit as a complete unit e 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 e Do not operate the microwave oven when the inverter grounding plate and fixing screw is loose It is very dangerous to operate the inverter circuit board without a proper ground connection HV INVERTER U INVERTER SUPPORT BRACKET figure 1Assembly of the inverter circuit board 5 Schematic Diagram 6 Wiring Diagram PRIMARY LATCH SWITCH TOP NOTE WHEN REPLACIN ANY COMPONENT S RECONNECT THE WIRE HARNESS ACCORDIN T O THE COLOURS BELOW COL OURS INDICATED INSIDE BRACKETS INDICATE THE COLOUR O THE CONNECTOR HOUSIN SECONDARY LATCH SWITCH BOTTOM OUTSIDE BR YF HOT LI E CAUTION HEAT SINK ER YHIH OL TAE NN AND TEMPERATURE SS POWER RELAY RY1 MA NETRON SHORT SWITCH BOTTOM INSIDE SYMBOL COLOUR BL BLUE BK BLACK BR BROWN WH WHITE YE YELLOW N NATURAL R RED 7 Description of the Operating Sequence 7 1 Variable power cooking control The output power is controlled by the inverter power supply The level of output from the inver
6. screws holding the orifice assembly Remove 2 screws holding the fan motor assembly Detatch the orifice assembly and the fan motor assembly from the microwave oven Remove the fan blade from the fan motor by pulling outward ONAWAYW oO figure 10 Removing the fan motor 9 6 Door replacement 1 Carefully lever door C away from Door E using a flat blade screwdriver 2 Remove 4 screws holding the door E to the door A assembly 3 Remove the door screen B by unclipping the screen B from the door A catch hooks Take care when removing the door screen B from door A it is possi ble to damage the catch hooks on the doorA 4 Remove the door key and spring from the door E After replacing component parts of the door fol low the instructions below for proper installation and adjustment of the door this is to prevent microwave leakage 1 When mounting the door to the oven adjust the door parallel to the bottom of the oven face plate by adjusting the upper hinge Adjust the door so there is no play between the inner door surface and the front of the microwave oven If the door assembly is not mounted properly microwave energy may leak from the clearance between the door and microwave oven 3 Perform the microwave leakage test 2 DOOR A ee ___ DOOR SCREEN B _ DOOR E m n il b HOOK rid DOOR C figure 11 Disassembly of the door
7. switch replacement When replacing faulty switches check the mounting tabs on the door hook assembly are not bent broken or defi cient in their ability to hold the switches e Refer to the schematic and wiring diagram to ensure the plug connectors on the wire harness are con nected to correct switches 11 1 Installation of primary latch switch secondary latch switch and short switch 1 When mounting the primary latch switch secondary latch switch and short latch switch to the door hook assembly Follow the instructions in lt elemtextfig ure 17 NOTE No specific adjustment during the insulation of each switch into the door hook is necessary When mounting the door hook assembly to the oven assembly adjust the door hook assembly by moving it in the direction of the arrow figure 17 Ensuring the door does not have any play in it Check for play by pulling the door assembly Make sure that the latch keys move smoothly after adjustment is completed Completely tighten the screws holding the door hook assembly to the oven assembly 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 lt elemtext 11 2 Measurement of microwave output The output power of the magnetron can be determined by performing the IEC standard test However due to the complexity of the IEC test procedures it is r
8. HADOG08002C2 Service Manual Microwave Oven INVERTER NN A574SBBTQ NN A554WBBTQ NN A524MBBTQ Power source 230 240VAC Single Phase 50Hz Power requirements Microwave 1180W Grill 1380W Convection 1390W Micro Grill Combi 2380W Micro Conv Combi 2390W Output IEC60705 Microwave 1000W Grill 1300W Convection 1300W Microwave frequency 2450 Mhz Timer 99 min 99 second Oven cavity size 27L Outside dimensions 510mm W x 390mm D X 305MM H Inside dimensions 359mm W X 352mm D x 217mm H Weight 13Kg Specifications subject to change without notice Panasonic 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 IMPORTANT SAFETY NOTICE 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 p
9. IC 2 No microwave oscillation 1 IC 1 pin 18 and 16 Abnormal IC 1 during high power Normal 18 5V Step 2 operation 16 5V 2 Q221 transistor Dark or unclear display 1 Replace display Abnormal Display Normal IC 1 Missing segments in display Replace IC 1 Abnormal IC 1 Normal Display 22 Microwave oven shuts down between 15 33 seconds Set the microwave oven to test mode Set to high power 1 minute H97 or H98 appears in the dis play and the microwave oven stops working Program for 1 minute and per form the following test Unplug CN702 connec tor and measure the 1 Latch switch 2 DPC Power relay voltage between the Step 2 terminlas Unplug CN703 connec DPC tor and measure the voltage at Pin 1 1 Magnetron 2 Inverter circuit 12 7 Checking the semiconductors using a resistance meter Diode Cp Transistor ij iy Digital transistor M Om K D K Forward Reverse Dt Low Q CO C Forward Reverse ME Low Q 00 E Low Q OO CO CO C Forward Reverse Ber E B Low Q 00 E C B Low Q CO C E oo 00 E Forward Reverse Cond E B 10 30 KQ 10 30 kQ 5 B C B 50 90 KQ 00 C E 40 60 kQ CO 23
10. PERATURE HOT LIVE HEAT SINK HEAT SINK RECTIFIER BRIDGE O CHOKE COIL FILM CAPACITORS O T D e SN SAND BAR RESISTOR E em o 0 CURRENT TRANSFORMER HIGH VOLTAGE DIODES PRESET VOLUME DO NOT ADJUST Or HIGH VOLTAGE CONTROL BOARD CAPACITORS WITH CUSTOM IC o PHOTOCOUPLER ids EN SH HIGH VOLTAGE TRANSFORMER figure 3 HV Inverter warning WARNING INVERTER POWER SUPPLY GROUNDING Check the high voltage inverter power supply circuit grounding The high voltage inverter circuit board must be connected to the microwave oven chassis If the inverter board is not grounded it exposes very high voltages and causes extreme DANGER Ensure that the HIGH VOLTAGE REMAINS IN CAPACITORS inverter circuit is properly grounded via the inverter earth bracket Earth Bracket figure 4 Grounding of the inverter circuit board WARNING DISCHARGE THE HIGH VOLTAGE CAPACI TORS For about 30 seconds after the oven is turned off an electric charge remains in the high voltage capacitors on the inverter circuit board figure 5 Discharging the high voltage capacitors 1 Before replacing or testing parts discharge these high voltage capacitors by shorting the inverter ouput terminal to the microwave oven chassis Remove the power plug from the mains outlet Ensure that the high voltage lead is connected to the inverter output terminals and the magnetron input termina
11. arts 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 1 Contents 1 Contents 5 4 2e aes eee SOR a RUN E CR RI CN DR E alo QW we ee V REA Eine 2 2 Feature Charto Ss 3s oe EL E esci etes Qs e dera se Quale Ba E QR Sata ea SU M cB ete Qu 3 3 Control Panel celere ee 4 4 Inverter Warnings rsee ee 5 5 Oven Schematic a a i oec aec e eun tw a RR ese A Aa ta Ras d a RR E ane URN oo ae E RR 6 6 Wiring Diagram rrlrrrhhhhhhhh ee 7 7 Description of Operation 000 cee eee erret 8 8 Cautions when Troubleshooting sse rer 9 9 Part Replacement Procedure eee eee r 12 10 Component Test Procedure ees 15 11 Measurements and Adjustments l l 17 12 Troubleshooting Guide sse ssh hhnihh nonno 18 13 Parts List Luo bu ae Rv EASE Is rc EPIO QUE else a wees DOR TENE qua RE IQ NU Eu a 24 14 Exploded VieW cric er SoS eis oe nh ewe 28 323 833 312 3 RR SR ee RR ee Yon d 26 15 Door ASSy 33 Eo Rx oe a eres RR LR RUN EUR ISO RU RR Eom Ey os ee AUR RARE S RE 27 16 Escutcheon Base crece eren hh hh hh htt 29 17 Packing and Accessories ss eee 31 18 Digital Programmer Circuit sse ee 32 2 Feature Chart Function All Models Mic
12. ative way to test the inverter circuit by monitoring the input current to the microwave oven The microwave oven shuts down between 15 and 33 seconds If the microwave oven shuts down after a short period of time while operating in micropower mode conduct the following test The microwave oven must be set in self test mode to activate the self diagnostic failure code system rad Micro Power Stop Cancel O CD When the microwave oven is set in test mode place a water load 1Ltr in the oven set micropower to high and time to 1 minute press start A short time after the start pad is pressed H97 H98 appears in the display window and the magnetron does not oscillate 21 H97 H98 appears in the display window Check oven input current More than 0 5A Y Check magnetron filament continuity OK Refer to component test procedures Open Magnetron A DANGER S HIGH K VOLTAGE DPC board Power Relay Less than 0 4A Loose wiring gt Latch Switch DPC control signal Stop If all the previous checks are OK there may be an v H V Inverter fault NOTE Check the continuity of the magnetron filament Check the filament is not shorted to the magnetron case NOTE DO NOT try to REPAIR the inverter power supply DO NOT ADJUST THE PRESET VOLUME on the inverter circuit board It is very dangerous to repair or adjust this pres
13. ecom mended you test the magnetron using the simple method outlined below Necessary equipment e 1 litre beaker e Glass thermometer e Wrist watch or stop watch NOTE Check the line voltage under load Low line voltage lowers the magnetron output Take the tem perature readings and heating time as accurate as pos sible 1 Fill the beaker with exactly one liter of tap water Stir the water using the thermometer and record the waters temperature Record as T1 Place the beaker on the center of the glass cook plate Operate the microwave for 1 minute on FULL power 4 Stir the water again and read the temperature of the water Record as T2 The normal temperature rise at the high power posi tion for each model is shown in the table figure 18 5 SCREW PRIMARY LATCH SWITCH SHORT LATCH SWITCH SECONDARY LATCH SWITCH 0 SWITCH SWITCH La 9 q cap lt 0 7mm ACTUATOR LEVER figure 17 Adjustment of latch switches RATED OUTPUT TEMPERATURE RISE 1000W 8 C Degrees centigrade figure 18 Temperature rise 12 Troubleshooting Guide Ha 9 do Caution Do not try to repair the H V Inverter power supply Replace the inverter circuit board as a complete unit Do not adjust the preset volume on the Inverter It is very dangerous to repair or adjust without special test equiptment the inverter handles very high voltage and current
14. en unpacking installing or mov ing the unit as some exposed edges may be sharp to touch and cause injury if not handled with care 11 9 Part Replacement Procedure 9 1 Magnetron 1 Discharge the high voltage capacitors on the inverter circuit 2 Remove the 1 screw holding air guide A 3 Remove the 2 screws holding the tie bar 4 Remove the oven lamp and lead wire harness from air guide A 5 Remove the air guide A 6 Disconnect the 2 high voltage leads from the magn etron 7 Remove the 4 screws holding the magnetron NOTE After replacing the magnetron tighten the mounting screws so there is no gap between the waveguide and the magnetron this prevents microwave leakage Caution When replacing the magnetron ensure that the antenna gasket is in place Note The magnetron used for this model is unique for the inverter power supply system Only fit the magnetron listed in the service manual parts list AIR GUIDE A figure 6 Removal of the magnetron 9 2 Inverter circuit 1 Discharge the high voltage capacitors 2 Remove 2 screws holding the tie bar 3 Unplug the H V Lead wires from the magnetron Remove the 1 screw holding the earth wire to the magnetron 5 Remove the connector CN701 and CN702 from the inverter PCB figure 8 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
15. er set to the lowest resistance scale Unplug the lead wires to the primary latch switch and secondary latch switch Test the continuity of each switch with an ohm meter set to the lowest resistance scale The test must be completed with the microwave oven door open and closed Normal continuity readings should be as follows Door Closed 0 Q Close Door Open 00 Open Primary Latch Switch Secondary Latch switch o0 O Open 0 Q Close Power relay B 00 CM Open oo Q Close 10 2 Short switch and monitor circuit 1 Unplug the lead wires from the high voltage inverter primary terminals Connect the test probes of the ohm meter to these leads 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 2 3 Door Open Door Closed Monitor switch oQ oo 10 3 Magnetron Continuity checks can only indicate an open filament or a shorted magnetron To diagnose an open filament or shorted magnetron 1 Disconnect the high voltage lead wires from the magnetron input terminals 2 Check the continuity across the magnetron filament terminals a good magnetron indicates a resistance of 1 ohm or less Check the continuity between each filament termi nal and the magnetron case a good magnetron indicates infinite 00 resistance figure 15 Tes
16. et without correct test equipment Do not attempt to repair the inverter circuit board replace the inverter circuit board with a new unit 12 6 Digital programmer circuit troubleshooting SYMPTOM STEP CHECK RESULT CORRECTION No display when the microwave 1 Fuse pattern on DPC Normal STEP 2 oven is first plugged in Open Note1 Shorted circuit ZNR LVT Lamp Microwave Ovens dead 2 IC10 pin 9 Abnormal OV ICi0 12V line Normal 12V Step 3 3 IC 1 pin 73 Abnormal ZB10 Q10 Ribbon cable Emitter of Q10 Normal 5V Step 4 4 IC 1 pin 27 Abnormal IC 220 pin 15 of IC220 Normal IC1 CX1 NOTE a Remove the jumper wire PF2 The procedure for repairing the fuse pattern on the DPC is as follows 1 Fuse pattern PF2 open circuit b Move the jumper wire PF3 into the postion of PF2 and solder inplace Replace the DPC if both the fuse pattern PF2 and PF3 are open circuit Note After repairing the fuse pattern on the DPC check the varistor for any burns and measure the winding resistance of the low voltage transformer primary coil No key input 1 Push button switch Abnormal Push button switch Normal IC 1 No beep sound 1 IC1 pin 12 Abnormal IC 1 Normal IC 220 BZ310 Power relay RY2 does not 1 IC 1 pin 23 during Abnormal operate operation Normal 5V 2 Create a short circuit RY2 does not turn on RY2 between pin 6 and pin RY2 turns on IC 220 16 of
17. ls 4 Short the magnetron input terminal to the micro wave oven chassis using an insulated handle screw driver 5 Always touch the microwave oven chassis and then the magnetron terminal WN WARNING There is high voltage with high current capabilities in the primary secondary windings choke coil and heat sink on the inverter circuit When power is connected to the microwave oven it is extremely dangerous to work on or near these inverter circuit components DO NOT measure the voltage in the high voltage circuit including the filament voltage of the magnetron WARNING Never touch any circuit wiring during operation 8 3 Part replacement When replacing any component in the microwave oven always ensure that the power cord is removed from the wall outlet 8 4 When the 10A fuse is blown due to the operation of the short switch WARNING Always replace both the short switch and the primary latch 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 be sure the mount ing tabs are not bent broken or deficient in their ability to hold the switches 8 5 Oven cavit
18. n page Check adjustment of the Door Pri mary secondary and short latch switches NOTE 1 All of these switches must be replaced at the same time Refer to adjustment instructions page Check continuity of power relay RY1 Replacce this relay if it is short cir cuit 19 12 3 Troubleshooting other problems Symptom Cause Correction 1 Microwave output is low 1 Decrease in power source volt Consult electrician Oven takes a long time to cook food age Refer to output test procedures 2 Open or loose wiring of magne tron filament circuit causing inter mittent oscillation Change magnetron 3 Ageing of magnetron 2 Loud Buzzing noise can be heard 1 Loose fan or fan motor 3 Turntable motor does not rotate 1 Open or loose wiring of turntable motor 2 Defective turntable motor 4 Oven stops operation during cooking 1 Open or loose wiring of primary Adjust door and latch switches cycle and secondary latch switch 5 Oven returns to plug in state 9 1 Open steam sensor circuit seconds after the start pad is 2 Defective steam sensor pressed in sensor cooking mode 12 4 Troubleshooting the inverter by input voltage Troubleshooting the Inverter circuit and magnetron Microwave oven shuts down between 15 33 seconds If the microwave oven shuts down after a short period of time while operating in micropower mode conduct the following tes
19. oven Remove the air guide E Remove the 4 screws holding the inverter circuit board to the inverter support base Figure 7 o Caution When replacing the inverter circuit as Check the grounding plate is in place 2 Securely tighten the grounding plate screw through the side of the oven chassis 3 Connect the 3 lead wire plugs into the correct sock ets Ensure there is enough space between the heat sink and other components Check that no lead wires are touching the aluminium heat sink HW INVERTER U f rs e js By P t f INVERTER SUPPORT BRACKET figure 7 Removal of the inverter PCB figure 8 Disconnecting the PCB locking plug 9 3 Digital Programmer Circuit DPC and membrane key board NOTE Ground any static electric from your body before handling the digital programmer circuit DPC 1 Disconnect all lead wire plugs from the DPC 2 Release the ribbon cable from the DPC 3 Remove 2 screws holding the escutcheon base to the microwave oven chassis To remove the escutcheon base open the microwave oven door and slide the escutcheon base upward slightly Remove the 6 screws holding the DPC DU assembly 4 5 Remove the door lever 6 Remove the 7 screws holding the DPC AU assembly To remove escutcheon pad 1 Remove the escutcheon bracket from the escutch eon base by freeing the 4 catch hooks 2 Peel away the display window from the inside of the base
20. pened NN A554W or Stop Cancel Pad is pressed once Start Pad has to be pressed again to continue cooking The design of your control panel may vary from the panel displayec depending on colour but the words Beep Sound on the pads will be the same A beep sounds when a pad is pressed If this beep does not sound the setting is incorrect When the oven changes from one function to another two beeps sound After completion of cooking five beeps sound 4 Inverter Warnings The inverter circuit board supplies the magnetron tube with a very high voltage 4000 volts HIGH VOLTAGE AREA 1 HEAT SINK DO NOT TOUCH RECTIFIER BRIDGE HOT HIGH VOLTAGE 2 LZ R CHOKE COIL 7 VA VA FILM CAPACITORS il F P P A SAND BAR RESISTOR E 4 M M q CURRENT TRANSFORMER A 4 HIGH VOLTAGE DIODES PRESET VOLUME 4 7 e Re DO NOT ADJUST 94 HIGH VOLTAGE CONTROL BOARD CAPACITORS WITH CUSTOM IC PHOTOCOUPLER CN 701 CN 703 HIGH VOLTAGE TRANSFORMER Danger e The inverter circuit board operates at high voltages and high temperatures The Inverter PCB e Operates at a very high voltage and current e Has an aluminium heat sink which becomes very hot e Has capacitors in the circuitry that hold a high volt age charge even when the oven is not operating Warning e Do not touch the high voltage circuit When replac ing the board care must be taken to avoid possible electric shock
21. rowave 6 Grill 3 Convection 13 Combi Yes Weight reheat 4 Weight cook 2 Weight combination 1 Weight defrost 3 Auto Preheat 3 Delay Stand Yes Kg Ib Yes Stage Cooking 3 Clock 12h Word prompt English 3 Control Panel Control Panel 1 Display Window 2 Time Pads 3 Auto Weight Microwave Programs 4 Auto Weight Combination 1 Programs 5 Auto Weight Defrost Programs Chaos Defrost 6 Microwave Power Pad AUTGREHEAT 7 Grill Pad 4 40 z Cury 8 Convection Pad h min 2 Chinese 9 Combination Pad e 3 10 Delay Stand Pad 1 10 3 En This can be used to delay a cooking po ao program for up to 9 hrs 99 mins or OK used to time or for standing non 6 RM E Veg cooking time 11 Clock Pad 7 um b 7 Grill 4 2 3 7 Potatoes J 8 f Xj E 12 Ib oz Conversion Pad Convection gt E Potato J 13 Weight Selection Pads 8 Products 4 9 Combination 14 Stop Cancel Pad 9 Before Cooking 9 Chicken 4 one press clears your instructions p During Cooking one press temporarily stops the 6 MRA ie is A cooking program Another press 12 cancels all your instructions and the Delay Ib 4 dom time of day will appear in the 10 sani Cock gj osa pue display zi 11 L 13 15 Start Pad 14 Stop Cancel Start 45 Press to start operating the oven If during cooking the door is o
22. t The microwave oven must be set in self test mode to activate the self diagnostic failure code system peny Micro Power Stop Cancel O E 3 When oven is set in test mode place water load 1Ltr in the oven set micropower to high and time for 1 minute press start H97 H98 appears in the display window for a short time after start key is pressed and there is no microwave oscil lation 20 DANGER H97 H98 appears in HIGH the display window VOLTAGE v Check magnetron Open gt Check the continuity of the magnetron filament continuity Magnetron filament Check the fialment is not shorted to the OK Y magnetron case Check Inverter input AC OV eee MR d relay oose relay wiring voltages at CN702 Latch switch AC 240V Unplug CN702 and test for 240VAC across the lead wire connector Check Inverter control ov NOTE DO NOT try to REPAIR the inverter signal at CN701 gt DPC board power supply DO NOT ADJUST Pin 1 and 2 THE PRESET VOLUME on the inverter circuit Approx AC 3V Unplug CN702 and test for board It is very dangerous to repair or adjust this 3 VAC acorss the lead wire preset without correct test equipment connector H V Inverter Do not attempt to repair the inverter circuit board NOTE replace the inverter circuit board with a new unit 12 5 Troubleshooting inverter by microwave oven input current This is an altern
23. ter circuit is controlled by a pulse width modulated signal from the digital programmer circuit DPC The digital program mer circuit operates relay RY1 to supply power to the inverter circuit NOTE If the microwave cooking time is longer than 3 minutes the cooling fan will operate for 1 minute to cool the oven and its electronic components 7 2 Auto weight defrost Auto weight Cook When an auto control feature is selected and the start Auto weight defrost pad pressed 1 The digital programmer circuit determines the power level and the cooking time and indicates the operating state in the display The table shows the corresponding cooking times and weights for the selected category 2 When the cooking time in the display window has elapsed the oven turns off automatically 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 Category ist Touch weight Cooking time Bread 100g 0 Min 45 Sec Meat items 200g 2 Min 40 Sec Meat joints 400g 8 Min 20 Sec Auto Weight Cook Category 1st Touch weight Cooking time 1 Curry 300g 3 Min 30 Sec 2 Chinese Style 200g 2 Min 10 Sec 3 Pasta 250g 2 Min 55 Sec 4 Casserole 300g 3 Min 15 Sec 5 Fresh Vegetables 100g 2 Min 20 Sec 6 Fresh Fish 100g 1 Min 30 Sec 8 Ca
24. ting the magnetron 10 4 Push button keyboard Check the continuity between the switch terminals on the DPC AU by tapping an appropriate pad on the key board and measuring the resistance across the corre sponding tracks on the ribbon cable 10 5 Inverter power supply Caution DO NOT try to repair this inverter power supply Replace this inverter power supply as a unit DANGER HIGH VOLTAGE AND TEMPERATURE HOT LIVE HEAT SINK HEAT SINK RECTIFIER BRIDGE O CHOKE COIL 2 FILM CAPACITORS O 27 X SAND BAR RESISTOR pese o o 0 CURRENT TRANSFORMER HIGH VOLTAGE DIODES PRESET VOLUME E DO NOT ADJUST Oy CONTROL BOARD HIGH VOLTAGE CAPACITORS WITH CUSTOM IC o PHOTOCOUPLER CN 702 CN 701 HIGH VOLTAGE TRANSFORMER HIGH VOLTAGE REMAINS IN CAPACITORS figure 16 Inverter circuit board layout 10 6 Inverter power supply unit Warning Do not attempt to make any measurements in the high voltage circuit of the inverter or magnetron See troubleshooting of the inverter circuit and magne tron on lt elemtextto determine if the inverter power supply is still functioning 16 11 Measurements and Adjustments Warning e Only replace parts with parts from the original man ufacturer e When the 10 amp fuse is blown due to the operation of the short switch you must replace the primary latch switch and short switch Then follow the installation procedures below e Interlock
25. utions to be Observed when Troubleshooting The microwave oven is a high voltage high current device Although it is free from danger in ordinary use extreme care should be taken during repair Caution Servicemen should remove their watches whenever working close to or replacing the magnetron 8 1 Check the grounding Do not operate the microwave oven on a two wire extension cord The microwave oven is designed to be used only when grounded It is imperative that the appliance is properly grounded before beginning repair work 8 2 Inverter Warnings DANGER HIGH VOLTAGE AND HIGH TEMPERATURES ON THE INVERTER POWER SUPPLY This high voltage inverter power supply supplies very high voltage and current to the magnetron Though it is free from danger in ordinary use extreme care should be taken during repair This circuit looks like a TV flyback transformer however the currents and volt ages in this circuit are very high this means this circuit is extremely dangerous The aluminium 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 the microwave oven DANGER HIGH VOLTAGE AND TEM
26. y aperatures Never insert a wire or any other metal object through the lamp holes or other aperatures in the oven cavity because such objects may work as an antenna and cause microwave leakage 8 6 Confirm after repair 1 After repair or replacement of parts make sure that the screws of the oven are neither loose nor miss ing Microwaves might leak if screws are not prop erly tightened 2 Make sure that all electrical connections are tight before inserting the plug into the wall outlet 3 Check for microwave energy leakage Refer to pro ceedure for measuring microwave energy leakage CAUTION MICROWAVE ENERGY Microwave energy is emitted from the magnetron attenna into the oven cavity via the wave guide Do not opearate the microwave oven if the door is defective the magnetron is not fitted correctly or the outer panel is removed IMPORTANT NOTICE When the microwave oven is operating the following components carry a potential above 240VAC Magnetron High voltage transformer Located on inverter High voltage diodes Located on inverter High voltage capacitors Located on inverter Pay special attention in these areas When the appliance is operated with the door hinges or magnetron fixed incorrectly the microwave leakage can reach more than 5mW cm 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 wh
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