Sharp R-520LW, R-520LK service manual Troubleshooting Guide, When the testing is completed

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R - 5 2 0 L K

R-520LW

TROUBLESHOOTING GUIDE

Never touch any part in the circuit with your hand or an uninsulated tool while the power supply is con- nected.

When troubleshooting the microwave oven, it is helpful to follow the Sequence of Operation in performing the checks. Many of the possible causes of trouble will require that a specific test be performed. These tests are given a procedure letter which will be found in the "Test Procedure "section.

IMPORTANT: If the oven becomes inoperative because of a blown monitor fuse, check the monitor switch, relay (RY1) secondary interlock relay (RY2), door sensing switch and primary interlock switch before replacing the moni- tor fuse. If the monitor fuse is replaced, the monitor switch must also be replaced. Use part FFS-BA016/KIT as an assembly.

IMPORTANT: Whenever troubleshooting is performed with the power supply cord disconnected. It may in, some cases, be necessary to connect the power supply cord after the outer case has been removed, in this event:

1.Disconnect the power supply cord, and then remove outer case.

2.Open the door and block it open.

3.Discharge high voltage capacitor.

4.Disconnect the leads to the primary of the power transformer.

5.Ensure that the leads remain isolated from other components and oven chassis by using insulation tape.

6.After that procedure, reconnect the power supply cord.

When the testing is completed

1.Disconnect the power supply cord, and then remove outer case.

2.Open the door and block it open.

3.Discharge high voltage capacitor.

4.Reconnect the leads to the primary of the power transformer.

5.Reinstall the outer case (cabinet).

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Contents Table of Contents 520LWBefore Servicing When the testing is completed Dont Touch Before ServicingMicrowave Measurement Procedure RequirementsLeakage test Sharp PLAZA, Mahwah Microwave Ovens520LK/R-520LW ForewordSpecification General InformationDescription Grounding InstructionsOven Diagram Touch Control PanelPower Level P-0 to P-90 Cooking OperationDescription of Operating Sequence OFF ConditionSensor Cooking Condition MicrowaveSchematic Clock Appears on DisplayDescription and Function of Components Troubleshooting Guide Test Procedures Test ProcedureProblem Procedure Component Test Letter Magnetron Assembly TestProcedure Component Test Letter Microwave Output PowerPower Transformer Test Procedure Component Test Letter High Voltage Rectifier Test Cavity Temperature Fuse TestMagnetron Temperature Fuse Test High Voltage Capacitor TestReplace Temperature Fuse Primary Interlock Switch TestRun the oven and check all functions Secondary Interlock System TestProcedure Component Test Letter Monitor Switch Test Touch Control Panel Assembly TestFigure of all digits flicker KEY Unit TestRelay Test Compu Defrost TestMenu 1ST Stage 2ND Stage 3RD Stage STEAKS/CHOPS Level Time Primary on the PWB, this foil pattern acts as a fuse Steps Occurrence Cause or CorrectionTesting Method for AH Sensor AND/OR Control Unit AH Sensor TestChecking the initial sensor cooking condition Checking Control Unit R1, R2 22Ω ± 1% 1/2W R3 4.3Ω ± 5% 1/4W R4 1MΩ ± 5% 1/4WSensor Dummy Resistor Circuit Reset Circuit Indicator CircuitPower Source Circuit Synchronizing Signal CircuitDescription of LSI LSISignal similar to ANI3 Internal clock oscillation frequency control input settingPower source voltage Key strobe signalConverter power source voltage GND0V Converter power source voltageCommon data signal Absolute Humidity Sensor Circuit Structure of Absolute Humidity SensorOperational Principle of Absolute Humidity Sensor Detector Circuit of Absolute Humidity Sensor CircuitOther Precautions Touch Control Panel ServicingServicing of Touch Control Panel Servicing ToolsComponent Replacement and Adjustment Procedure Outer Case RemovalTo prevent an electric shock, take the following pre Power Transformer Removal Re-installHigh Voltage Rectifier and High Voltage Capacitor Removal Magnetron RemovalPositive Lock Connector NO-CASE Type Removal Control Panel Assembly RemovalGraphic Sheet and Membrane Switch Replacement Oven Lamp and Lamp Socket RemovalInstallation Turntable Motor RemovalInstallation Cooling FAN Motor RemovalRemoval Rear ViewDoor Replacement After adjustment, check the followingRE-INSTALL After any service, make sure of the followingSealer Film Diagram High Voltage ComponentsCircuit Control Unit Figure S-5 . Printed Wiring Board of Power Unit Parts List HOW to Order Replacement Parts MiscellaneousSCREWS,NUTS and Washers Model NumberOven and Cabinet Parts Control Panel Parts Door Parts Miscellaneous Packing and Accessories Copyright 2006 by Sharp Corporation ALL Rights Reserved

R-520LK, R-520LW specifications

The Sharp R-520LW and R-520LK are innovative microwave ovens that combine advanced technology with user-friendly features to enhance cooking experiences. Designed with modern kitchens in mind, these models embody efficiency, precision, and versatility.

One of the defining characteristics of both the R-520LW and R-520LK is their powerful 900-watt output, which allows for speedy cooking and reheating. This high wattage ensures that food is cooked evenly and retains its moisture, preventing the common issue of dry or unevenly heated meals. Furthermore, the inclusion of multiple cooking power levels provides users with flexibility, making it easy to select the ideal setting for various types of food.

Both models feature Sharp's signature Inverter Technology. Unlike traditional microwaves that use a turn-on and turn-off cycling method, inverter technology delivers a steady stream of cooking power. This results in more consistent heating, allowing delicate foods such as fish or custards to be cooked perfectly without overcooking the edges. This technology not only enhances the quality of cooked food but also improves the overall efficiency of the microwave.

The R-520LW and R-520LK come equipped with a variety of auto-cook settings that cater to different culinary needs. From popcorn to frozen vegetables, these pre-programmed settings allow users to prepare meals with just a touch of a button, making cooking uncomplicated for all skill levels. The large, user-friendly control panel features intuitive buttons and a digital display, ensuring effortless operation and visibility.

In terms of design, the R-520LW boasts a sleek white finish, while the R-520LK offers a modern black aesthetic. Both models are compact yet spacious, with a generous interior capacity that can accommodate a range of dish sizes. The turntable feature further enhances cooking efficiency by ensuring even cooking all around.

Cleaning and maintaining the R-520LW and R-520LK is a breeze, thanks to their easy-to-wipe surfaces and the interior's cavity that can be easily accessed. The durable construction of these microwaves means they are designed to withstand the rigors of daily use.

In summary, the Sharp R-520LW and R-520LK microwave ovens stand out with their advanced features, such as inverter technology and pre-programmed cooking settings, making them excellent choices for anyone looking to streamline their kitchen tasks. Their stylish designs and user-friendly interfaces further enhance their appeal, making them valuable additions to any modern home.
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