Sharp R-21JCA-F service manual Noise Filter Test, Control Panel Assembly Test, Before testing

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R-21JCA-F

TEST PROCEDURES

PROCEDURE

LETTER

COMPONENT TEST

HBLOWN MONITOR FUSE 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.If the monitor fuse is blown when the door is opened, check the primary interlock relay, secondary interlock switch and monitor switch according to the "TEST PROCEDURE" for those switches before replacing the blown monitor fuse.

CAUTION: BEFORE REPLACING A BLOWN MONITOR FUSE, TEST THE PRIMARY INTERLOCK RELAY, SECONDARY INTERLOCK SWITCH, DOOR SENSING SWITCH AND MONITOR SWITCH FOR PROPER OPERATION.

If the monitor fuse is blown by improper switch operation, the monitor fuse and monitor switch must be replaced with "monitor fuse and monitor switch assembly" part number FFS-BA015WRK0, even if the monitor switch operates normally. The monitor fuse and monitor switch assembly is comprised of a 20 ampere fuse and 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.

INOISE FILTER 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.

N

 

 

 

 

L

4.

Disconnect the lead wires from the terminal the noise

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

FUSE

 

filter. Using an ohmmeter, check between the terminals

 

 

 

 

 

 

 

 

 

 

 

 

 

 

20A

 

 

LINE CROSS CAPACITOR 0.22 F AC250V

 

as described in the following table. If incorrect reading are

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NOISE SUPPRESSION COIL

 

obtained, replace the noise filter.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5.

Reconnect all leads removed from components during

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

testing.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

6.

Reinstall the outer case (cabinet).

 

LINE BYPASS

LINE BYPASS

 

CAPACITOR

CAPACITOR

7.

Reconnect the power supply cord after the outer case is

 

0.003300 F / AC 125V

0.003300 F / AC 125V

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

installed.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

WHITE

 

 

 

 

RED

8.

Run the oven and check all functions.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NOISE FILTER

MEASURING POINT

INDICATION OF OHMMETER

 

 

Between N and L

Open circuit

 

 

Between terminal N and WHITE

Short circuit

 

 

Between terminal L and RED

Short circuit

 

 

JCONTROL PANEL ASSEMBLY TEST

WARNING : To prevent an electric shock do not touch the electrical parts and the printed wiring board. Because the control unit is "TRANSLESS CIRCUIT" and many electrical parts are used at A.C. line voltage.

The control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore, unlike conventional microwave ovens, proper maintenance cannot be performed with only a voltmeter and ohmmeter. In this service manual troubleshooting by unit replacement is described according to the symptoms indicated.

Before testing,

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

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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