Sharp R-480J service manual KEY Unit Test, Relay Test

Page 15

R-480J

 

TEST PROCEDURES

 

 

PROCEDURE

COMPONENT TEST

LETTER

 

b)At a certain digit, brightness is low.

c)Only one indicator does not light.

d)The corresponding segments of all digits do not light up; or they continue to light up.

e)Wrong figure appears.

f)A certain group of indicators do not light up.

g)The figure of all digits flicker.

2-3 Other possible troubles caused by defective control unit.

a)Buzzer does not sound or continues to sound.

b)Clock does not operate properly.

c)Cooking is not possible.

LKEY UNIT TEST

If the display fails to clear when the STOP/CLEAR pad is depressed, first verify the flat ribbon cable is making good contact, verify that the door 2nd. interlock relay control switch operates properly; that is the contacts are closed when the door is closed and open when the door is open. If the 2nd. interlock relay control switch is good, disconnect the flat ribbon cable that connects the key unit to the control unit and make sure the 2nd. interlock relay control switch is closed (either close the door or short the 2nd. interlock relay control switch connector). Use the key unit matrix indicated on the control panel schematic and place a jumper wire between the pins that correspond to the STOP/CLEAR pad making momentary contact. If the control unit responds by clearing with a beep the key unit is faulty and must be replaced. If the control unit does not respond, it is faulty and must be replaced.

If a specific pad does not respond, the above method may be used (after clearing the control unit) to determine if the control unit

or key pad is at fault.

 

 

G1

 

 

 

G2

 

 

G3

 

 

 

G4

 

 

 

G5

 

 

G6

 

 

G7

 

 

G8

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CARRY OUT 3D CHECKS.

 

LOW FAT

 

 

EASY

 

 

 

 

 

1

 

 

2

 

3

 

4

 

 

5

 

 

G9

 

MEALS

 

DEFROST

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

EXPRESS

EXPRESS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DESSERTS

 

 

MEAL

 

COOK

 

6

 

 

7

 

8

 

9

 

 

0

 

 

G10

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

INSTANT

 

 

 

 

 

 

 

 

EXPRESS

 

 

 

 

 

 

 

 

 

VEGETABLES

 

 

 

 

 

 

 

 

 

 

 

COOK

 

 

TIMER

 

CLOCK

 

 

 

 

 

G11

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

START

 

 

 

 

 

 

 

 

DEFROST

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SENSOR

VEGETARIAN

 

 

 

 

 

 

POWER

 

 

 

 

 

STOP

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

LESS

 

HELP

 

MORE

 

G12

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

REHEAT

MEALS

 

 

 

LEVEL

 

CLEAR

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RICE/

QUICK &

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

G13

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PASTA

 

EASY

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

G14

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MRELAY TEST

Remove the outer case and check voltage between Pin No 1 of the 2-pin connector (A) and the normal open terminal of the relay RY1 on the power unit with an A.C. voltmeter. The meter should indicate 230 - 240 volts, if not check oven circuit.

RY1 and RY2 Relay Test

These relays are operated by D.C. voltage.

Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation. DC. voltage indicated ............... Defective relay.

DC. voltage not indicated ......... Check diode which is connected to the relay coil. If diode is good,

control unit is defective.

RELAY SYMBOL

OPERATIONAL VOLTAGE

CONNECTED COMPONENTS

 

 

 

RY1

APPROX. 25.0V D.C.

Oven lamp / Turntable motor / Cooling fan motor

RY2

APPROX. 24.0V D.C.

Power transformer

 

 

 

CARRY OUT 4R CHECKS.

NPROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING BOARD (PWB) IS OPEN

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. If the foil pattern is open, follow the troubleshooting guide given below for repair.

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Contents Microwave Oven Model R-480J Table of Contents480J General Important Information Sharp Corporation OSAKA, JapanMicrowave Oven 480JThis Appliance Must be Earthed Product SpecificationsGeneral Information DescriptionTouch Control Panel Appearance ViewVariable Cooking Operation SequenceOFF Condition Microwave Cooking ConditionPower Output Reduction Cooking SequenceSensor Instant Reheat Function of Important Components Remember to Check 4R Troubleshooting GuideServicing Remember to Check 3DProblem Test Procedure Possible Cause Defective PartsTest Procedures Procedure Component Test Letter Magnetron TestMicrowave Output Power 1 litre water load High Voltage Capacitor Test Test Procedures Letter Component TestPower Transformer Test High Voltage Rectifier Assembly TestThermal CUT-OUT Test Procedure Component Test LetterSwitch Test Noise Filter Test Carry OUT 3D ChecksTouch Control Panel Assembly Test Blown Fuse F10A Carry OUT 3D ChecksHigh Voltage Fuse Test Relay Test KEY Unit TestChecking the initial sensor cooking condition Carry OUT 3D Checks Steps Occurrence Cause or CorrectionOmif AH Sensor TestSensor Dummy Resistor Circuit Test Procedures LetterTesting Method for AH Sensor AND/OR Control Unit Checking Control UnitSynchronizing Signal Circuit Reset CircuitIndicator Circuit Power Source CircuitLSI Power source voltage GND0V Pin No Signal DescriptionSignal coming from touch key Signal similar to P17Common data signal COM5 Common data signal COM8Common data signal COM7 Common data signal COM6Structure of Absolute Humidity Sensor Absolute Humidity Sensor CircuitServicing of Touch Control Panel Other PrecautionsTouch Control Panel Servicing Shapes of Electronic ComponentsComponent Replacement and Adjustment Procedure Power Transformer RemovalOuter Case Removal Turntable Motor Removal Positive Lock Connector NO-CASE Type RemovalHOW to RE-INSTALL the Turntable Motor Cover Magnetron RemovalOven Lamp and Lamp Socket Removal Control Panel Assembly RemovalCPU Unit and Power Unit InstallationSide View Power Supply Cord ReplacementAfter adjustment, check the following Rear ViewView back side of door frame Door ReplacementRE-INSTALL RemovalAfter any service, make sure of the following InstallationSealer Film Holaday HI Simpson 380M Preparation for TestingMicrowave Measurement RequirementFigure O-1. Oven Schematic-OFF Condition High Voltage Components Figure S-1. Pictorial DiagramFigure S-2. Power unitl Circuit FigureS3.CPU UnitRY1 RY3 TTM CN CZD1 SP1 VRB RY2 CN a CN D D10Parts List Not replaceable items Packing and AccessoriesMiscellaneous SCREWS, Nuts and Washers84-21 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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