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Sharp MMD24B, MMD24S manual Test Procedures, Component Test, Letter, L Blown Monitor Fuse Test

Models: MMD24S MMD24B

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LBLOWN MONITOR FUSE TEST

MMD24S

MMD24B

TEST PROCEDURES

PROCEDURE	COMPONENT TEST
LETTER	COMPONENT TEST
LETTER

LBLOWN MONITOR FUSE TEST

1.Disconnect the power supply cord.

2.Open the drawer and block it open.

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

4.If the monitor fuse is blown when the drawer is opened, check the primary interlock switch, 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,TESTthe SECONDARY interlock SWITCH, sTOP 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-BA018/KIT, 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.Reassemble the unit.

7.Reconnect the power supply cord.

8.Run the oven and check all functions.

MPOWER TRANSFORMER TEST

1.Disconnect the power supply cord.

2.Open the drawer and block it open.

3.Discharge high voltage capacitor.

4.Disconnect the primary input terminals and measure the resistance of the transformer with an ohmmeter. Check for continuity of the coils with an ohmmeter. On the R x 1 scale, the resistance of the primary coil should be less than 1 ohm and the resistance of the high voltage coil should be approximately 90 ohms; the resistance of the filament coil should be less than 1 ohm.

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.

(HIGH VOLTAGES ARE PRESENT AT THE HIGH VOLTAGE TERMINAL, SO DO NOT ATTEMPT TO MEASURE THE FILAMENT AND HIGH VOLTAGE.)

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Sharp MMD24B, MMD24S manual Test Procedures, Component Test, Letter, L Blown Monitor Fuse Test, M Power Transformer Test

Contents

WARNING TO SERVICE PERSONNEL TABLE OF CONTENTSSERVICE MANUAL WARNING TO SERVICE PERSONNELBEFORE SERVICING Before Servicing WARNING TO SERVICE PERSONNELAfter repairing When the testing is completedA. Requirements MICROWAVE MEASUREMENT PROCEDUREB. Preparation for testing C. Leakage testSERVICE MANUAL DANGER1440 Bridge Gate Dr Diamond Bar, CA If provided, Vent Hood, Fan assembly, Cooling Fan MotorMICROWAVE DRAWER SPECIFICATION DESCRIPTIONGENERAL INFORMATION GROUNDING INSTRUCTIONSDESCRIPTION OF OPERATING SEQUENCE POWER LEVEL P-0 TO P-90 COOKINGOPERATION OFF CONDITIONSENSOR COOKING CONDITION Cooking SequenceMICROWAVE SCHEMATIC OFF CONDITION CLOSED, COOK OFF CONDITTIONDOOR A TOUCH CONTROL PANEL ASSEMBLY TEST TEST PROCEDURESPROCEDURE Before testingCOMPONENT TEST TEST PROCEDURESPROCEDURE LETTERCheck supply voltage and oven power cord TEST PROCEDURESPROCEDURE LETTERTESTING METHOD FOR AH SENSOR AND/OR CONTROL UNIT TEST PROCEDURESPROCEDURE COMPONENT TESTCOMPONENT TEST TEST PROCEDURESPROCEDURE LETTERPROCEDURE Refer to the disassembly instructions found on PageTEST PROCEDURES G MAGNETRON ASSEMBLY TESTI SECONDARY INTERLOCK SWITCH TEST TEST PROCEDURESPROCEDURE J STOP SWITCH TESTM POWER TRANSFORMER TEST TEST PROCEDURESPROCEDURE COMPONENT TEST4 Reset Circuit TOUCH CONTROL PANEL ASSEMBLYControl Unit and Power Unit 5 Indicator CircuitPower source voltage 0V GND DESCRIPTION OF LSI IC-1Power source voltage 0V GND Internal clock oscillation frequency setting inputSegment data signal SignalCommon data signal Signal coming from touch keyCommon relay driving signal. Square Waveform 60Hz SignalMagnetron high-voltage circuit driving signal Signal to sound buzzer1 Structure of Humidity Sensor HUMIDITY SENSOR CIRCUITventilation opening for sensing 2 Operational Principle of Humidity Sensor4. Other Precautions TOUCH CONTROL PANEL SERVICING1 Servicing the touch control panel with power supply of the oven 2. Servicing of Touch Control Panel1. Employing lead-free solder PRECAUTIONS FOR USING LEAD-FREE SOLDER2. Using lead-free wire solder 3. SolderingWARNING AGAINST HIGH VOLTAGE COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDUREWARNING FOR WIRING To prevent an electric shock, take the following pre- cautionsMICROWAVE DRAWER DISASSEMBLY Un-hook/Attach White AC Wire to Bottom Terminal POWER CORD REPLACEMENTUn-hook/Attach Black AC Wire to Top Terminal Un-hook/Attach Ground to metal Tab on Back PlateRe-install STOP SWITCH, SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH REMOVALSTOP SWITCH, SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH ADJUSTMENT After adjustment, check the followingDRAWER/SLIDE RAIL REMOVAL DRAWER ASSEMBLY AND CHOKE REMOVALDRAWER SUPPORT ANGLE REMOVAL 1. Follow the Microwave Drawer disassembly as previouslyACTUATOR REMOVAL/ADJUSTMENT SWITCH ANGLE REMOVAL/ADJUSTMENTSWITCH ANGLE REMOVAL Actuator adjustmentRACK GEAR REMOVAL AUTO DRAWER GEAR REMOVAL/INSTALLATIONBottom cover InstallationMMD24B HIGH VOLTAGE COMPONENTSMMD24S to Back PlateFM A Figure S-2. Power Unit CircuitMICRO CN-AMMD24S MMD24B UNITCONTROL UNITMMD24S MMD24B Figure S-4. Printed Wiring Board of Power Unit2.5A A B C D E F G HMMD24B 5.PrintedWiringBoardMMD24S UnitControlofCOPYRIGHT 2008 BY DACOR, INC ALL RIGHTS RESERVED MMD24S MMD24B