Sharp R-21JCA-F Primary Interlock System Test, Door Sensing Switch, Primary Interlock Relay RY1

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WHT/ WHT
SCREW DRIVER
MONITOR
SWITCH

R-21JCA-F

TEST PROCEDURES

PROCEDURE

LETTER

COMPONENT TEST

FSECONDARY INTERLOCK SWITCH 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.Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal of the switch. The meter should indicate an open circuit with the door open and a closed circuit with the door closed. If improper operation is indicated, replace the secondary interlock switch.

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.

PRIMARY INTERLOCK SYSTEM TEST

DOOR SENSING SWITCH

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.Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal of the switch. The meter should indicate an open circuit with the door open and a closed circuit with the door closed. If improper operation is indicated, replace the door sensing switch.

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.

NOTE: If the door sensing switch contacts fail in the open position and the door is closed, the cooling fan, antenna and oven light will be activated by RY1.

PRIMARY INTERLOCK RELAY (RY1)

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 two (2) wire leads from the male tab terminals of the Primary Interlock Relay. Check the state of the relay contacts using a ohmmeter. The relay contacts should be open. If the relay contacts are closed, replace the circuit board entirely or the relay itself.

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.

GMONITOR SWITCH 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.Before performing this test, make sure that the secondary interlock switch and the primary interlock relay are operating properly, according to the above Switch Test Procedure. Disconnect the wire lead from the monitor switch (COM) terminal. Check the monitor switch operation by using the ohmmeter as follows. When the door is open, the meter should indicate a closed circuit. When the monitor switch actuator is pushed by a screw driver through the lower latch hole on the front plate of the oven cavity with the door opened (in this condition the plunger of the monitor switch is pushed in), the meter should indicate an open circuit. If improper operation is indicated, the switch may be defective. After testing the monitor switch, reconnect the wire lead to the monitor switch

(COM) terminal and check the continuity of the monitor circuit.

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.

OHMMETER

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Contents Model R-21JCA-F Before Servicing When the testing is completed Dont Touch Before ServicingLeakage test Microwave Measurement ProcedureRequirements Light Duty Commercial Microwave Oven 21JCA-F Foreword Sharp Electronics CorporationMaximum width, depth and height SpecificationGeneral Information Actual capacity for holding food is lessOven Diagram 10 6OFF Condition OperationDescription of Operating Sequence Cooking ConditionFigure O-1 Oven Schematic-OFF Condition FM AMDescription and Function of Components Problem Troubleshooting GuideTest Procedure Possible Case Defective Parts Microwave Output Power Power Transformer TestThermal CUT-OUT Test 145˚C Magnetron High Voltage Capacitor TestThermal CUT-OUT Test 125˚C Oven Primary Interlock System Test Door Sensing SwitchMonitor Switch Test Primary Interlock Relay RY1Noise Filter Test Control Panel Assembly TestBefore testing Test Procedures Letter Component Test Relay TestSteps Occurrence Cause or Correction Touch Control Panel Assembly Description of LSIInternal clock oscillation frequency input setting Pin No Signal Description Auto clear terminalPower source voltage Power source voltage +5VServicing of Touch Control Panel Other PrecautionsTouch Control Panel Servicing Servicing ToolsEmploying lead-free solder Precautions for Using LEAD-FREE SolderUsing lead-free wire solder SolderingOuter Case Removal Component Replacement and Adjustment ProcedurePower Transformer Removal Oven Lamp and Lamp Socket Removal Control Panel Assembly RemovalMagnetron Removal Cooling FAN Motor Removal Positive Lock Connector NO-CASE Type RemovalAntenna Motor Removal Rear ViewRemoval Power Supply Cord ReplacementRe-install Door Parts Removal Removal Antenna Motor Shaft ReplacementAfter any service, make sure of the following Installation of Ceramic Shelf Figure C-10. Stirrer Antenna Assembly InstallationPictorialDiagram HighvoltagecomponentsCN-A3 Pin5mm Pitch Figure S-3. Printed Wiring Board Cabinet Parts Parts ListElectric Parts Control Panel PartsMiscellaneous HOW to Order Replacement PartsDoor Parts SCREWS,NUTS and WashersOven and Cabinet Parts Control Panel Parts Packing and Accessories Copyright 2005 by Sharp Corporation ALL Rights Reserved