Sharp R-480J service manual Test Procedures Letter Component Test, Power Transformer Test

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R-480J

TEST PROCEDURES

PROCEDURE

LETTER

COMPONENT TEST

 

 

 

 

 

 

 

 

 

 

Room temperature

To = 21˚C

Initial temperature

T1 = 11°C

 

Temperature after (35 + 3) = 38 sec

T2 = 21°C

 

Temperature difference Cold-Warm (∆T = T2 - T1)

∆T = 10°C

 

Measured output power

 

 

 

 

The equation is “P = 120 x ∆T”

........................................... P = 120 x 10°C = 1200 Watts

 

 

 

 

 

JUDGEMENT: The measured output power should be at least ± 15 % of the rated output power.

CAUTION: 1°C CORRESPONDS TO 120 WATTS REPEAT MEASUREMENT IF THE POWER IS INSUFFICIENT.

1000g

 

1000g

 

1000g

 

 

 

T1˚C

 

Heat up for 38 sec.

T2˚C

 

 

 

 

 

BPOWER TRANSFORMER TEST

WARNING: High voltages and large currents are present at the secondary winding and filament winding of the power transformer. It is very dangerous to work near this part when the oven is on. NEVER make any voltage measurements of the high-voltage circuits, including the magnetron filament.

CARRY OUT 3D CHECKS.

Disconnect the leads to the primary winding of the power transformer. Disconnect the filament and secondary winding connections from the rest of the HV circuitry. Using an ohmmeter, set on a low range, it is possible to check the continuity of all three windings. The following readings should be obtained:

a. Primary winding

approx. 1.0

Ω

b. Secondary winding

approx. 84

Ω

c. Filament winding

less than 1Ω

If the reading obtained are not stated as above, then the power transformer is probably faulty and should be replaced.

CARRY OUT 4R CHECKS.

CHIGH VOLTAGE RECTIFIER ASSEMBLY TEST

HIGH VOLTAGE RECTIFIER TEST

B

 

 

C

 

 

 

 

 

 

 

 

CARRY OUT 3D CHECKS.

 

 

 

 

 

 

HIGH VOLTAGE RECTIFIER

Isolate the high voltage rectifier assembly from the HV circuit. The high voltage rectifier can be tested using an ohmmeter set to its highest range. Connect the ohmmeter across the terminal B+C of the high voltage rectifier and note the reading obtained. Reverse the meter leads and note this second reading. The normal resistance is infinite in one direction and more than 100 kΩ in the other direction.

CARRY OUT 4R CHECKS.

NOTE: FOR MEASUREMENT OF THE RESISTANCE OF THE RECTIFIER, THE BATTERIES OF THE MEASURING INSTRUMENT MUST HAVE A VOLTAGE AT LEAST 6 VOLTS, BECAUSE OTHERWISE AN INFINITE RESISTANCE MIGHT BE SHOWN IN BOTH DIRECTIONS.

DHIGH VOLTAGE CAPACITOR TEST

CARRY OUT 3D CHECKS.

A. Isolate the high voltage capacitor from the circuit.

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Contents Table of Contents Microwave Oven Model R-480J480J Sharp Corporation OSAKA, Japan Microwave Oven480J General Important InformationProduct Specifications General InformationDescription This Appliance Must be EarthedAppearance View Touch Control PanelOperation Sequence OFF ConditionMicrowave Cooking Condition Variable CookingPower Output Reduction Cooking SequenceSensor Instant Reheat Function of Important Components Troubleshooting Guide ServicingRemember to Check 3D Remember to Check 4RTest Procedure Possible Cause Defective Parts ProblemTest Procedures Procedure Component Test Letter Magnetron TestMicrowave Output Power 1 litre water load Test Procedures Letter Component Test Power Transformer TestHigh Voltage Rectifier Assembly Test High Voltage Capacitor TestProcedure Component Test Letter Switch TestNoise Filter Test Carry OUT 3D Checks Thermal CUT-OUT TestTouch Control Panel Assembly Test Blown Fuse F10A Carry OUT 3D ChecksHigh Voltage Fuse Test KEY Unit Test Relay TestCarry OUT 3D Checks Steps Occurrence Cause or Correction OmifAH Sensor Test Checking the initial sensor cooking conditionTest Procedures Letter Testing Method for AH Sensor AND/OR Control UnitChecking Control Unit Sensor Dummy Resistor CircuitReset Circuit Indicator CircuitPower Source Circuit Synchronizing Signal CircuitLSI Pin No Signal Description Signal coming from touch keySignal similar to P17 Power source voltage GND0VCommon data signal COM8 Common data signal COM7Common data signal COM6 Common data signal COM5Absolute Humidity Sensor Circuit Structure of Absolute Humidity SensorOther Precautions Touch Control Panel ServicingShapes of Electronic Components Servicing of Touch Control PanelComponent Replacement and Adjustment Procedure Power Transformer RemovalOuter Case Removal Positive Lock Connector NO-CASE Type Removal HOW to RE-INSTALL the Turntable Motor CoverMagnetron Removal Turntable Motor RemovalControl Panel Assembly Removal CPU Unit and Power UnitInstallation Oven Lamp and Lamp Socket RemovalPower Supply Cord Replacement After adjustment, check the followingRear View Side ViewDoor Replacement RE-INSTALLRemoval View back side of door frameAfter any service, make sure of the following InstallationSealer Film Preparation for Testing Microwave MeasurementRequirement Holaday HI Simpson 380MFigure O-1. Oven Schematic-OFF Condition Figure S-1. Pictorial Diagram High Voltage ComponentsFigure S-2. Power unitl Circuit Unit FigureS3.CPUCN C ZD1 SP1 VRB RY2CN a CN D D10 RY1 RY3 TTMParts List Packing and Accessories MiscellaneousSCREWS, Nuts and Washers Not replaceable items84-21 Control Panel Parts Door Parts Miscellaneous Copyright 2004 by Sharp Corporation ALL Rights Reserved

R-480J specifications

The Sharp R-480J is a notable microwave oven that combines advanced technology with practical design, catering to both everyday cooking needs and more complex culinary tasks. This model is designed for consumers seeking reliability and efficiency in their kitchen appliances.

One of the standout features of the Sharp R-480J is its powerful 900-watt output. This high wattage allows for faster cooking times, making meal preparation a breeze. The microwave also offers multiple power levels, which provides the user with the flexibility to cook a variety of dishes. Whether you are reheating leftovers, defrosting meats, or cooking fresh vegetables, the R-480J delivers consistent and thorough results.

The microwave is equipped with a spacious interior, accommodating larger dishes with ease. Its turntable design ensures even cooking by allowing food to rotate during the cooking process. This feature minimizes cold spots in the food, ensuring that meals are heated uniformly.

User-friendliness is a key aspect of the Sharp R-480J. The appliance comes with an intuitive control panel featuring pre-programmed settings for common food items such as popcorn, pizza, and dinner plates, making it easy for users to select the right cooking time and power level with just a few button presses. Additionally, the digital display shows cooking times and power levels clearly, enhancing the overall cooking experience.

The R-480J also incorporates advanced sensor cooking technology. This innovative feature detects humidity levels emitted by food and adjusts cooking time accordingly. This means users can achieve perfect results without constantly monitoring the microwave, allowing for greater convenience and efficiency in daily cooking.

Moreover, the microwave's sleek and modern design fits well into various kitchen aesthetics. Its easy-to-clean surfaces minimize maintenance efforts, while the compact build allows it to be placed in smaller kitchens without taking up too much space.

In conclusion, the Sharp R-480J microwave oven stands out for its powerful performance, user-friendly features, and practical design. Its combination of high wattage, multiple power levels, and sensor cooking technology makes it a versatile appliance for any kitchen. Whether tackling daily meals or experimenting with new recipes, the R-480J is equipped to meet diverse cooking needs with ease and efficiency.
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