Sharp R-480J Touch Control Panel Servicing, Shapes of Electronic Components, Servicing Tools

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R-480J

TOUCH CONTROL PANEL SERVICING

1.Precautions for Handling Electronic Components This unit uses CMOS LSI in the integral part of the circuits. When handling these parts, the following precautions should be strictly followed. CMOS LSI have extremely high impedance at its input and output terminals. For this reason, it is easily influenced by the surrounding high voltage power source, static electric- ity charge in clothes, etc. and sometimes it is not fully protected by the built-in protection circuit.

In order to protect CMOS LSI.

1)When storing and transporting, thoroughly wrap them in aluminium foil. Also wrap all PW boards containing them in aluminium foil.

2)When soldering, ground the technician as shown in the figure and use grounded soldering iron and work table.

approx. 1M ohm

2. Shapes of Electronic Components

 

Transistor

 

Transistor

 

2SB1238

 

 

 

KRC243M

 

B

 

 

 

 

E

C

 

C B

 

 

 

 

E

 

 

 

3. Servicing of Touch Control Panel

We describe the procedures to permit servicing of the touch control panel of the microwave oven and the precautions you must take when doing so. To perform the servicing, power to the touch control panel is available either from the power line of the oven itself or from an external power source.

(1)Servicing the touch control panel with power sup- ply of the oven:

CAUTION:

THE HIGH VOLTAGE TRANSFORMER OF THE MI- CROWAVE OVEN IS STILL LIVE DURING SERVIC- ING PRESENTS A HAZARD.

Therefore, when checking the performance of the

touch control panel, put the outer cabinet on the oven to avoid touching the high voltage transformer, or unplug the primary terminal (connector) of the high voltage transformer to turn it off; the end of such connector must be insulated with an insulating tape. After servicing, be sure to replace the leads to their original locations.

A.On some models, the power supply cord between the touch control panel and the oven itself is so short that the two can’t be separated.

For those models, check and repair all the controls (sensor-related ones included) of the touch control panel while keeping it connected to the oven.

B.On some models, the power supply cord between the touch control panel and the oven proper is long enough that they may be separated from each other. For those models, therefore, it is possible to check and repair the controls of the touch control panel while keeping it apart from the oven proper; in this case you must short both ends of the door sensing switch (on PWB) of the touch control panel with a jumper, which brings about an operational state that is equivalent to the oven door being closed. As for the sensor-related controls of the touch control panel, checking them is possible if dummy resistor(s) with resistance equal to that of the controls are used.

(2)Servicing the touch control panel with power supply from an external power source:

Disconnect the touch control panel completely from the oven proper, and short both ends of the door sensing switch (on PWB) of the touch control panel, which brings about an operational state that is equivalent to the oven door being closed. Connect an external power source to the power input terminal of the touch control panel, then it is possible to check and repair the controls of the touch control panel it is also possible to check the sensor-related controls of the touch control panel by using the dummy resistor(s).

4. Servicing Tools

Tools required to service the touch control panel assembly.

1)Soldering iron: 30W

(It is recommended to use a soldering iron with a grounding terminal.)

2)Oscilloscope: Single beam, frequency range: DC- 10MHz type or more advanced model.

3)Others: Hand tools

5. Other Precautions

1)Before turning on the power source of the control unit, remove the aluminium foil applied for preventing static electricity.

2)Connect the connectors of the key unit to the control unit being sure that the lead wires are not twisted.

3)After aluminium foil is removed, be careful that abnor- mal voltage due to static electricity etc. is not applied to the input or output terminals.

4)Attach connectors, electrolytic capacitors, etc. to PWB, making sure that all connections are tight.

5)Be sure to use specified components where high precision is required.

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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 ConditionSensor Instant Reheat Power Output ReductionCooking Sequence Function of Important Components Remember to Check 4R Troubleshooting GuideServicing Remember to Check 3DProblem Test Procedure Possible Cause Defective PartsMicrowave Output Power 1 litre water load Test ProceduresProcedure Component Test Letter Magnetron Test 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 ChecksHigh Voltage Fuse Test Touch Control Panel Assembly TestBlown Fuse F10A Carry OUT 3D Checks 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 ComponentsOuter Case Removal Component Replacement and Adjustment ProcedurePower Transformer 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 RemovalSealer Film After any service, make sure of the followingInstallation 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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