Sharp MMD24S Test Procedures, Letter, Defrost Test, Steps, side of touch control transformer

Page 13
DEFROST TEST

TEST PROCEDURES

PROCEDURE

COMPONENT TEST

LETTER

 

MMD24S

MMD24B

12.Re-install the outer case (cabinet).

13.Reconnect the power supply cord after the outer case is installed. 14.Run the oven and check all function.

D

DEFROST TEST

 

 

 

 

 

 

 

 

WARNING : The oven should be fully assembled before following procedure.

 

(1)

Place one cup of water in the center of the tray in the oven cavity.

 

 

 

(2)

Close the drawer, touch the Defrost pad. Then select Steaks/Chops by touching the number pad

 

 

2. And touch the number pad 5. (Now, weight 0.5lb is set.) And then touch the start pad.

 

(3)

The oven is in Defrost cooking condition.

 

 

 

 

 

(4)

The oven will operate as follows

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

WEIGHT

1ST STAGE

2ND STAGE

3RD. STAGE

 

 

 

 

 

LEVEL

TIME

LEVEL

TIME

LEVEL

TIME

 

 

 

 

0.5lb

60%

20sec.

40%

20sec.

30%

45sec.

 

 

(5) If improper operation is indicated, the control unit is probably defective and should be checked.

 

 

E

PROCEDURES TO BE TAKEN WHEN THE FUSE ON THE PRINTED WIRING BOARD (PWB) IS OPEN.

To protect the electronic circuits, this model is provided with a fuse added to the primary on the PWB.

1.Fuse check and repairs.

1)Disconnect the power supply cord.

2)Remove the outer case cabinet.

3)Open the door and block it open.

4)Discharge high voltage capacitor.

5)If the Fuse is blown, replace power unit.

6)Make a visual inspection of the varistor. Check for burned damage. If the varistor has been burned, replace the power unit.

7)Examine the touch control transformer with a tester for the presence of layer short-circuit (check the primary coil resistance which is approximately 151.6Ω ± 10%). If any abnormal condition is detected, replace the touch control transformer.

8)Reconnect all leads removed from components during testing.

9)Re-install the outer case (cabinet).

10)Reconnect the power supply cord after the outer case is installed.

11)Run the oven and check all functions.

2.Follow the troubleshooting guide given below, if indicator does not light up after above check and repairs are finished.

1)Disconnect the power supply cord.

2)Remove the outer case cabinet.

3)Open the door and block it open.

4)Discharge high voltage capacitor.

5)Disconnect the leads to the primary of the power transformer.

6)Ensure that these leads remain isolated from other components and oven chassis by using insulation tape.

7)After that procedure, re-connect the power supply cord.

8)Follow the troubleshooting guide given below for repair.

STEPS

OCCURRENCE

CAUSE OR CORRECTION

1

The rated AC voltage is not present between
Check supply voltage and oven power cord.

 

Pin Nos. 5 and 7 of the 4-pin connecter (CN-A).

 

 

 

 

2

The rated AC voltage is present at primary
Touch control transformer or secondary circuit defective.

 

side of touch control transformer.

Check and replace touch control transformer or power unit

.

13

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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 CONDITIONCooking Sequence SENSOR COOKING CONDITIONMICROWAVE CLOSED, COOK OFF CONDITTION SCHEMATIC OFF CONDITIONDOOR PROCEDURE TEST PROCEDURESA TOUCH CONTROL PANEL ASSEMBLY TEST Before testingB KEY UNIT TEST COMPONENT TESTC RELAY TEST DEFROST TEST Check supply voltage and oven power cordSTEPS The rated AC voltage is not present betweenF AH SENSOR TEST Checking the initial sensor cooking condition TESTING METHOD FOR AH SENSOR AND/OR CONTROL UNITWater load cooking test 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 TESTJ STOP SWITCH TEST I SECONDARY INTERLOCK SWITCH TESTK MONITOR 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 H2.5A Figure S-4. Printed Wiring Board of Power UnitA B C D E F G H UnitControlof 5.PrintedWiringBoardCOPYRIGHT 2008 BY DACOR, INC ALL RIGHTS RESERVED
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