Sharp R-21JCA-F service manual Dont Touch Before Servicing, When the testing is completed

Page 3

R-21JCA-F

WARNING TO SERVICE PERSONNEL

Microwave ovens contain circuitry capable of pro- ducing very high voltage and current, contact with following parts may result in a severe, possibly fatal, electrical shock.

(Example)

High Voltage Capacitor, High Voltage Power Trans- former, Magnetron, High Voltage Rectifier Assem- bly, High Voltage Harness etc..

Read the Service Manual carefully and follow all instructions.

Don't Touch !

Danger High Voltage

Before Servicing

1. Disconnect the power supply cord ,

a n d t h e n

remove outer case.

 

2.Open the door and block it open.

3.Discharge high voltage capacitor.

WARNING:RISK OF ELECTRIC SHOCK. DISCHARGE THE HIGH-VOLTAGE CAPACITOR BEFORE SERVICING.

The high-voltage capacitor remains charged about 60 sec- onds after the oven has been switched off. Wait for 60 seconds and then short-circuit the connection of the high- voltage capacitor (that is the connecting lead of the high- voltage rectifier) against the chassis with the use of an insulated screwdriver.

Whenever troubleshooting is performed the power supply must be disconnected. It may in, some cases, be necessary to connect the power supply after the outer case has been removed, in this event,

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 the leads remain isolated from other components and oven chassis by using insulation tape.

6.After that procedure, reconnect the power supply cord.

When the testing is completed,

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.Reconnect the leads to the primary of the power transformer.

5.Reinstall the outer case (cabinet).

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

7.Run the oven and check all functions.

After repairing

1.Reconnect all leads removed from components during testing.

2.Reinstall the outer case (cabinet).

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

4.Run the oven and check all functions.

Microwave ovens should not be run empty. To test for the presence of microwave energy within a cavity, place a cup of cold water on the oven turntable, close the door and set the power to HIGH and set the microwave timer for two (2) minutes. When the two minutes has elapsed (timer at zero) carefully check that the water is now hot. If the water remains cold carry out Before Servicing procedure and re-examine the connec- tions to the component being tested.

When all service work is completed and the oven is fully assembled, the microwave power output should be checked and microwave leakage test should be carried out.

1

Page 2 Page 4
Image 3
Page 2 Page 4
Contents Model R-21JCA-F Before Servicing Dont Touch Before Servicing When the testing is completedMicrowave Measurement Procedure RequirementsLeakage test Sharp Electronics Corporation Light Duty Commercial Microwave Oven 21JCA-F ForewordActual capacity for holding food is less SpecificationGeneral Information Maximum width, depth and height10 6 Oven DiagramCooking Condition OperationDescription of Operating Sequence OFF ConditionFM AM Figure O-1 Oven Schematic-OFF ConditionDescription and Function of Components Troubleshooting Guide Test Procedure Possible Case Defective PartsProblem Power Transformer Test Microwave Output PowerHigh Voltage Capacitor Test Thermal CUT-OUT Test 125˚C OvenThermal CUT-OUT Test 145˚C Magnetron Primary Interlock Relay RY1 Door Sensing SwitchMonitor Switch Test Primary Interlock System TestControl Panel Assembly Test Before testingNoise Filter Test Relay Test Test Procedures Letter Component TestSteps Occurrence Cause or Correction Description of LSI Touch Control Panel AssemblyPower source voltage +5V Pin No Signal Description Auto clear terminalPower source voltage Internal clock oscillation frequency input settingServicing Tools Other PrecautionsTouch Control Panel Servicing Servicing of Touch Control PanelSoldering Precautions for Using LEAD-FREE SolderUsing lead-free wire solder Employing lead-free solderComponent Replacement and Adjustment Procedure Power Transformer RemovalOuter Case Removal Control Panel Assembly Removal Magnetron RemovalOven Lamp and Lamp Socket Removal Rear View Positive Lock Connector NO-CASE Type RemovalAntenna Motor Removal Cooling FAN Motor RemovalPower Supply Cord Replacement Re-installRemoval Door Parts Removal Antenna Motor Shaft Replacement After any service, make sure of the followingRemoval Figure C-10. Stirrer Antenna Assembly Installation Installation of Ceramic ShelfHighvoltagecomponents PictorialDiagramCN-A3 Pin5mm Pitch Figure S-3. Printed Wiring Board Control Panel Parts Parts ListElectric Parts Cabinet PartsSCREWS,NUTS and Washers HOW to Order Replacement PartsDoor Parts MiscellaneousOven and Cabinet Parts Control Panel Parts Copyright 2005 by Sharp Corporation ALL Rights Reserved Packing and Accessories
Top Page Image Contents