Sharp MMD24S manual Test Procedures, Letter, I Secondary Interlock Switch Test, J Stop Switch Test

Page 17
ISECONDARY INTERLOCK SWITCH TEST

TEST PROCEDURES

PROCEDURE

COMPONENT TEST

LETTER

 

ISECONDARY INTERLOCK SWITCH TEST

1.Disconnect the power supply cord.

2.Open the drawer and keep it open.

3.To discharge high voltage capacitor, wait for 60 seconds.

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 drawer open and a closed circuit with the drawer closed. If improper operation is indicated, replace the secondary interlock switch.

5.Reconnect all leads removed from components during testing.

6.Reassemble the unit.

7.Reconnect the power supply cord.

8.Run the oven and check all functions.

JSTOP SWITCH TEST

MMD24S

MMD24B

STOP SWITCH

1.Disconnect the power supply cord.

2.Open the drawer and keep it open.

3.To discharge high voltage capacitor, wait for 60 seconds.

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 drawer open and a closed circuit with the drawer closed. If improper operation is indicated, replace the stop switch.

5.Reconnect all leads removed from components during testing.

6.Reassemble the unit.

7.Reconnect the power supply cord.

8.Run the oven and check all functions.

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

KMONITOR SWITCH TEST

1.Disconnect the power supply cord.

2.Open the drawer and keep it open.

3.To discharge high voltage capacitor, wait for 60 seconds.

4.Before performing this test, make sure that the secondary interlock switch, 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 drawer 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 drawer 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 and both the monitor switch, plus fuse will need to be replaced. 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.Reassemble the unit.

7.Reconnect the power supply cord.

8.Run the oven and check all functions.

MONITOR

SWITCH

(BLK) JSTOP SWITCH TEST

(RED)

Ohmmeter KMONITOR SWITCH TEST

(BRN,GRY)

(BRN,BLK)

SECONDARY

INTERLOCK

SWITCH

Screw Driver

17

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Contents WARNING TO SERVICE PERSONNEL TABLE OF CONTENTSWARNING TO SERVICE PERSONNEL MICROWAVE MEASUREMENT PROCEDUREBEFORE SERVICING After repairing WARNING TO SERVICE PERSONNELBefore Servicing When the testing is completedB. Preparation for testing MICROWAVE MEASUREMENT PROCEDUREA. Requirements C. Leakage test1440 Bridge Gate Dr Diamond Bar, CA DANGERSERVICE MANUAL If provided, Vent Hood, Fan assembly, Cooling Fan MotorDESCRIPTION MICROWAVE DRAWER SPECIFICATIONGROUNDING INSTRUCTIONS GENERAL INFORMATIONOPERATION POWER LEVEL P-0 TO P-90 COOKINGDESCRIPTION OF OPERATING SEQUENCE OFF CONDITIONMICROWAVE SENSOR COOKING CONDITIONCooking Sequence DOOR SCHEMATIC OFF CONDITIONCLOSED, COOK OFF CONDITTION PROCEDURE TEST PROCEDURESA TOUCH CONTROL PANEL ASSEMBLY TEST Before testingC RELAY TEST COMPONENT TESTB KEY UNIT TEST DEFROST TEST Check supply voltage and oven power cordSTEPS The rated AC voltage is not present betweenWater load cooking test TESTING METHOD FOR AH SENSOR AND/OR CONTROL UNITF AH SENSOR TEST Checking the initial sensor cooking condition R1, R2 22Ω ± 1% 1/2W R3 4.3kΩ ± 5% 1/4W R4 1MΩ ± 5% 1/4W CHECKING CONTROL UNITG MAGNETRON ASSEMBLY TEST Refer to the disassembly instructions found on PageMICROWAVE OUTPUT POWER H THERMAL CUT-OUT TESTK MONITOR SWITCH TEST I SECONDARY INTERLOCK SWITCH TESTJ STOP SWITCH TEST L BLOWN MONITOR FUSE TEST M POWER TRANSFORMER TESTControl Unit and Power Unit TOUCH CONTROL PANEL ASSEMBLY4 Reset Circuit 5 Indicator CircuitPower source voltage 0V GND DESCRIPTION OF LSI IC-1Internal clock oscillation frequency setting input Power source voltage +5VSegment data signal SignalSignal coming from touch key Signal similar to P23Common relay driving signal. Square Waveform 60Hz Magnetron high-voltage circuit driving signalSignal to sound buzzer Signal to synchronize LSI with commercial power source frequencyventilation opening for sensing HUMIDITY SENSOR CIRCUIT1 Structure of Humidity Sensor 2 Operational Principle of Humidity Sensor1 Servicing the touch control panel with power supply of the oven TOUCH CONTROL PANEL SERVICING4. Other Precautions 2. Servicing of Touch Control Panel2. Using lead-free wire solder PRECAUTIONS FOR USING LEAD-FREE SOLDER1. Employing lead-free solder 3. SolderingWARNING FOR WIRING COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDUREWARNING AGAINST HIGH VOLTAGE To prevent an electric shock, take the following pre- cautionsMICROWAVE DRAWER DISASSEMBLY Un-hook/Attach Black AC Wire to Top Terminal POWER CORD REPLACEMENTUn-hook/Attach White AC Wire to Bottom Terminal Un-hook/Attach Ground to metal Tab on Back PlateSTOP SWITCH, SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH ADJUSTMENT STOP SWITCH, SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH REMOVALRe-install After adjustment, check the followingDRAWER SUPPORT ANGLE REMOVAL DRAWER ASSEMBLY AND CHOKE REMOVALDRAWER/SLIDE RAIL REMOVAL 1. Follow the Microwave Drawer disassembly as previouslySWITCH ANGLE REMOVAL SWITCH ANGLE REMOVAL/ADJUSTMENTACTUATOR REMOVAL/ADJUSTMENT Actuator adjustmentBottom cover AUTO DRAWER GEAR REMOVAL/INSTALLATIONRACK GEAR REMOVAL Installationto Back Plate HIGH VOLTAGE COMPONENTSMICRO Figure S-2. Power Unit CircuitFM A CN-ACONTROL UNITUNIT F G HA B C D E F G H Figure S-4. Printed Wiring Board of Power Unit2.5A UnitControlof 5.PrintedWiringBoardCOPYRIGHT 2008 BY DACOR, INC ALL RIGHTS RESERVED
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