Inverter NN-A574SBBTQ Service Manual

Text of Inverter NN-A574SBBTQ User Guide:

• 2 1Contents 1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2 Feature Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3 Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

• 21 12.5 Troubleshooting inverter by microwave oven input current This is an alternative 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

• Inverter NN-A574SBBTQ, 10 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 2. Remove the power plug from the mains outlet 3. Ensure that the high voltage lead is connected to the inverter output terminals and the magnetron input terminals. 4. Short the magnetr

• Inverter NN-A574SBBTQ, 13 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. 4. Remove the 6 screws holding the DPC DU assembly. 5. Remove the door lever. 6. Remove the 7 screws holding the DPC AU assembly. To remove escutcheon pad. 1. Remove the

• Inverter NN-A574SBBTQ, 18 12 Troubleshooting Guide Caution 1. Do not try to repair the H.V. Inverter power supply. Replace the inverter circuit board as a complete unit. 2. 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. 3. Do not attempt to measure the voltages in the microwave oven high voltage circuit. 4. Always discharge the high voltage capacitors on the inverter circuit board before troubleshooting. 5. When checking the continuity of the components on the H.V. Inverter circuit, unsolder and remove one leg of the component f

• Inverter NN-A574SBBTQ, 17 11 Measurements and Adjustments Warning • Only replace parts with parts from the original man- ufacturer. • 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. • Interlock 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. • Refer to the schematic and wiring diagram to ensure the plug connectors on the wire h

• 5 4 Inverter Warnings The inverter circuit board supplies the magnetron tube with a very high voltage (4000 volts). Danger • The inverter circuit board operates at high voltages and high temperatures. The Inverter PCB • Operates at a very high voltage and current. • Has an aluminium heat sink which becomes very hot. • Has capacitors in the circuitry th

• Inverter NN-A574SBBTQ, 4 AUTO REHEAT NN - A554W 1 2 Curry Chinese 9 Pizza 10 up down Delay/ Stand Clock oz Stop/Cancel Start lb Convection Grill 1 - 2 - 3 h min min sec 110 110 AUTO COOK 8 Potato Products 7 Jacket Potatoes 5 6 Fish Veg 3 4 Pasta Casserole Combination Micr o Power Chicken Control Panel NN-A554/A524/A574* (1) Display Window (2) Time Pads (3) Auto Weight Microwave Programs (4) Auto Weight Combination Programs (5) Auto Weight Defrost Programs (Chaos Defrost) (6) Microwave Power Pad (7) Grill Pad (8) Convection Pad (9) Combination Pad (10) Delay/Stand Pad: This can be used to delay a cooking program for up to 9 hrs 9

• Inverter NN-A574SBBTQ, 20 12.3 Troubleshooting (other problems) 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 test. The microwave oven must be set in self test mode to activate the self diagnostic failure code system. When oven is set in test mode, place water load (1Ltr) in the oven, set micropower to high and time for 1 minute, p

• Inverter NN-A574SBBTQ, 11 When the appliance is operated with the door hinges or magnetron fixed incorrectly, the microwave leakage can reach more than 5mW/cm 3 . 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.

• Inverter NN-A574SBBTQ, 23 12.7 Checking the semiconductors using a resistance meter 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 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

• 16 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 <$elemtextto determine if the inverter power supply is still functioning. HEAT SINK RECTIFIER BRIDGE CHOKE COIL SAND BAR RESISTOR CURRENT TRAN

• Inverter NN-A574SBBTQ, 14 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. 2. 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 mic

• Inverter NN-A574SBBTQ, 3 2Feature Chart Function All Models Microwave 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/lb Yes Stage Cooking 3 Clock 12 h Word prompt English

• Inverter NN-A574SBBTQ, 19 12.1 Troubleshooting (no operation) 12.2 Troubleshooting (fuse blown) Symptom Cause Correction 1. Oven is dead. Fuse is OK No display and no operation at all. 1. Open or loose lead wire harness. 2. Open low voltage transformer. 3. Defective DPC AU or DPC DU 2. Oven does not accept key input (Program). 1. Key input is not in sequence. 2. Shorted push button on DPC AU 3. Defective DPC AU. Refer to operation procedure. Refer to DPC troubleshooting 3. Oven lamp and turntable motor turn on when the microwave oven is plugged in with the door closed. 1. Maladjusted or loose wiring of secondary latch switch. 2. Defective secondary latch switch. Adjust door an

• Inverter NN-A574SBBTQ, 22 12.6 Digital programmer circuit troubleshooting H97, H98 appears in the display window. Check oven input current. Check magnetron filament continuity. DPC board/Power Relay Loose wiring. Latch Switch. DPC control signal Magnetron* Stop!! If all the previous checks are OK, there may be an H.V. Inverter fault. NOTE: DANGER HIGH VOLTAGE Less than 0.4A More than 0.5A Open OK Refer to component test procedures *Check the continuity of the magnetron filament. Check the filament is not shorted to the magnetron case. NOTE: try to the inverter power supply. on the inverter circuit board. It is very dangerous to repair or adjust this

• Inverter NN-A574SBBTQ, 8 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 inverter 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 selec

• Inverter NN-A574SBBTQ, 9 8 Cautions 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.

• Inverter NN-A574SBBTQ, 15 10 Component Test Procedure Caution • The inverter circuit operates at high voltages. • Never attempt to measure the high voltage on the inverter circuit. • 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 meter set to the lowest resistance scale. 2. Unplug the lead wires to the primary latch switch and secondary latch switch. 3. Test the continuity of each switc

Related Products and Documents (Microwave Oven):

Comparable Devices:

Similar Resources:

• Sharp EBR-4800SL (16 pages) ENGLISHDEUTSCHFRANÇAISESPAÑOLNEDERLANDSITALIANOA32867,EBR-480011Instruction for SHARP Built-in Kit EBR-4800(SL)Before installing a Sharp Microwave Oven, read and check the following points.SAFETY INFORMATION1. Except U.K., for use in continental Europe only.The oven must be connected to an electric circuit provided with a switch (contact gap no less than 3 …

• Kenmore 721.68211890 (21 pages) _)__/__) Owner's Manual®MICROWAVE OVENModel No. 721.68211_iiiii!iiiii_iiii_iiii_iiiiii;;iiCAUTION" Read and followall Safety Rules and Operatinginstructions before First Useof this Product.Sears, Roebuck and Co., Hoffman Estates, IL. 60179 U.S.A. …

• Whirlpool GH9184XL (20 pages) MICROWAVE HOOD COMBINATIONUse & Care GuideFor questions about features, operation/performanceparts, accessories or service, call: 1-800-253-1301.or visit our website at...www.whirlpool.com Table of Contents .......................................24619-652-61532/8184733®Model GH9184XL …

• Miele H6300BM (136 pages)  …

• Sharp R-310AK (72 pages) SUPPLEMENTAL SERVICE MANUALSHARP ELECTRONICS CORPORATIONService Headquarters: Sharp Plaza, Mahwah, New Jersey 07430-2135R-310AKR-330AKR-330AWTABLE OF CONTENTSPagePRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICE TOAVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY ...................INSIDE FRONT COVERBEFORE SERVICING …

• Danby DMW799W (30 pages) DANBY PRODUCTS LIMITED, ONTARIO, CANADA N1H 6Z9DANBY PRODUCTS INC., FINDLAY, OHIO, USA 45840www.Danby.com2018.07.27MICROWAVEOwner’s Manual...........................1 - 14MICRO ONDEManuel du propriétaire................15 - 28MODEL • MODÈLEDMW799WDMW799BL …

Comments, Questions and Opinions: