Sharp R-520LW, R-520LK service manual Primary on the PWB, this foil pattern acts as a fuse

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R - 5 2 0 L K

R-520LW

 

TEST PROCEDURES

PROCEDURE

COMPONENT TEST

LETTER

 

 

 

L

FOIL PATTERN ON THE PRINTED WIRING BOARD TEST

 

To protect the electronic circuits, this model is provided with a fine foil pattern added to the

 

primary on the PWB, this foil pattern acts as a fuse.

1.Foil pattern check and repairs.

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)Follow the troubleshooting guide given below for repair.

STEPS

OCCURRENCE

CAUSE OR CORRECTION

 

 

 

1

Only pattern at "a" is broken.

*Insert jumper wire J1 and solder.

2

Pattern at "a" and "b" are broken.

*Insert the coil RCILF2003YAZZ between "c" and "d".

 

 

 

5)Make a visual inspection of the varistor. Check for burned damage and examine the transformer with a tester for the presence of layer short-circuit (check the primary coil resistance which is approximately 563ý ± 10%).If any abnormal condition is detected, replace the control unit assembly.

6)Reconnect all leads removed from components during testing.

7)Re-install the outer case (cabinet).

8)Reconnect the power supply cord after the outer case is installed.

9)Run the oven and check all functions.

 

 

 

RY2

 

 

a

 

c

J1

b

d

 

 

 

L1

 

 

 

 

VRS1

 

2. Follow the troubleshooting guide given below, if indicator does not light up after above check and

repairs are finished.

 

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 these leads remain isolated from other components and oven chassis by using

 

 

insulation tape.

 

6)

After that procedure, re-connect the power supply cord.

7)

Follow the troubleshooting guide given below for repair.

 

 

 

 

 

STEPS

OCCURRENCE

CAUSE OR CORRECTION

 

 

 

The rated AC voltage is not present between

 

 

 

1

the normal open terminal of the relay RY1 and

Check supply voltage and oven power cord.

 

 

 

the normal open terminal of the relay RY2.

 

 

 

 

 

 

 

 

2

The rated AC voltage is present at primary side

Low voltage transformer or secondary circuit defective.

 

 

 

of low voltage transformer.

Check and replace control unit assembly.

 

 

 

 

 

8)

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

9)

Open the door and block it open.

 

10)

Discharge high voltage capacitor.

 

11)

Reconnect all leads removed from components during testing.

12)

Re-install the outer case (cabinet).

 

13)

Reconnect the power supply cord after the outer case is installed.

14)

Run the oven and check all functions.

 

(5) The oven will operate for the first 16 seconds, without generating microwave energy.

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Contents Table of Contents 520LWBefore Servicing When the testing is completed Dont Touch Before ServicingLeakage test Microwave Measurement ProcedureRequirements 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 TestPower Transformer Test Procedure Component Test LetterMicrowave Output Power 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 TestMenu 1ST Stage 2ND Stage 3RD Stage STEAKS/CHOPS Level Time Relay TestCompu Defrost Test Primary on the PWB, this foil pattern acts as a fuse Steps Occurrence Cause or CorrectionChecking the initial sensor cooking condition Testing Method for AH Sensor AND/OR Control UnitAH Sensor Test Sensor Dummy Resistor Circuit Checking Control UnitR1, R2 22Ω ± 1% 1/2W R3 4.3Ω ± 5% 1/4W R4 1MΩ ± 5% 1/4W 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 signalCommon data signal Converter power source voltage GND0VConverter power source voltage 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 ToolsTo prevent an electric shock, take the following pre Component Replacement and Adjustment ProcedureOuter Case Removal 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 followingSealer Film RE-INSTALLAfter any service, make sure of the following 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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