Sharp R-520LW Procedure Component Test Letter, Microwave Output Power, Power Transformer Test

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R - 5 2 0 L K

R-520LW

TEST PROCEDURES

PROCEDURE

COMPONENT TEST

LETTER

 

4.To test for an open filament, isolate the magnetron from the high voltage circuit. A continuity check across the magnetron filament leads should indicate less than 1 ohm.

5.To test for a shorted magnetron, connect the ohmmeter leads between the magnetron filament leads and chassis ground. This test should indicate an infinite resistance. If there is little or no resistance the magnetron is grounded and must be replaced.

6.Reconnect all leads removed from components during testing.

7.Reinstall the outer case (cabinet).

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

9.Run the oven and check all functions.

MICROWAVE OUTPUT POWER

The following test procedure should be carried out with the microwave oven in a fully assembled condi- tion (outer case fitted).

HIGH VOLTAGES ARE PRESENT DURING THE COOK CYCLE, SO EXTREME CAUTION SHOULD BE OBSERVED.

Power output of the magnetron can be measured by performing a water temperature rise test. This test should only be used if above tests do not indicate a faulty magnetron and there is no defect in the following components or wiring: silicon rectifier, high voltage capacitor and power transformer. This test will require a 16 ounce (453cc) measuring cup and an accurate mercury thermometer or thermocouple type temperature tester. For accurate results, the following procedure must be followed carefully:

1.Fill the measuring cup with 16 oz. (453cc) of tap water and measure the temperature of the water with a thermometer or thermocouple temperature tester. Stir the thermometer or thermocouple through the water until the temperature stabilizes. Record the temperature of the water.

2.Place the cup of water in the oven. Operate oven at POWER 10(HIGH) selecting more than 60 seconds cook time. Allow the water to heat for 60 seconds, measuring with a stop watch, second hand of a watch or the digital read-out countdown.

3.Remove the cup from the oven and again measure the temperature, making sure to stir the thermometer or thermocouple through the water until the maximum temperature is recorded.

4.Subtract the cold water temperature from the hot water temperature. The normal result should be 33 to 62OF(18.6 to 34.5OC) rise in temperature. If the water temperatures are accurately measured and tested for the required time period the test results will indicate if the magnetron tube has low power output (low rise in water temperature) which would extend cooking time or high power output (high rise in water temperature) which would reduce cooking time. Because cooking time can be adjusted to compensate for power output, the magnetron tube assembly should be replaced only if the water temperature rise test indicates a power output well beyond the normal limits. The test is only accurate if the power supply line voltage is 120 volts and the oven cavity is clean.

BPOWER TRANSFORMER TEST

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 primary input terminals and measure the resistance of the transformer with an ohmmeter. Check for continuity of the coils with an ohmmeter. On the R x 1 scale, the resistance of the primary coil should be less than 1 ohm and the resistance of the high voltage coil should be approximately 90 ohms; the resistance of the filament coil should be less than 1 ohm.

5.Reconnect all leads removed from components during testing.

6.Reinstall the outer case (cabinet).

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

8.Run the oven and check all functions.

(HIGH VOLTAGES ARE PRESENT AT THE HIGH VOLTAGE TERMINAL, SO DO NOT ATTEMPT TO MEASURE THE FILAMENT AND HIGH VOLTAGE.)

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Contents Table of Contents 520LWBefore Servicing When the testing is completed Dont Touch Before ServicingLeakage test Microwave Measurement ProcedureRequirements 520LK/R-520LW Sharp PLAZA, MahwahMicrowave Ovens ForewordDescription SpecificationGeneral Information Grounding InstructionsOven Diagram Touch Control PanelDescription of Operating Sequence Power Level P-0 to P-90 CookingOperation OFF ConditionSensor Cooking Condition MicrowaveSchematic Clock Appears on DisplayDescription and Function of Components Troubleshooting Guide Problem Test ProceduresTest Procedure Procedure Component Test Letter Magnetron Assembly TestPower Transformer Test Procedure Component Test LetterMicrowave Output Power Magnetron Temperature Fuse Test Procedure Component Test Letter High Voltage Rectifier TestCavity Temperature Fuse Test High Voltage Capacitor TestRun the oven and check all functions Replace Temperature FusePrimary Interlock Switch Test 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 Power Source Circuit Reset CircuitIndicator Circuit Synchronizing Signal CircuitDescription of LSI LSIPower source voltage Signal similar to ANI3Internal clock oscillation frequency control input setting Key strobe signalCommon data signal Converter power source voltage GND0VConverter power source voltage Operational Principle of Absolute Humidity Sensor Absolute Humidity Sensor CircuitStructure of Absolute Humidity Sensor Detector Circuit of Absolute Humidity Sensor CircuitServicing of Touch Control Panel Other PrecautionsTouch Control Panel Servicing Servicing ToolsTo prevent an electric shock, take the following pre Component Replacement and Adjustment ProcedureOuter Case Removal High Voltage Rectifier and High Voltage Capacitor Removal Power Transformer RemovalRe-install Magnetron RemovalGraphic Sheet and Membrane Switch Replacement Positive Lock Connector NO-CASE Type RemovalControl Panel Assembly Removal Oven Lamp and Lamp Socket RemovalInstallation Turntable Motor RemovalRemoval InstallationCooling FAN Motor Removal 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 SCREWS,NUTS and Washers HOW to Order Replacement PartsMiscellaneous 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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