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SMD2470ASY

SMD3070ASY

OPERATION

DESCRIPTION OF OPERATING SEQUENCE 

The following is a description of component functions dur-
ing oven operation.

OFF CONDITION

Closing the drawer activates the door sensing switch and 
secondary interlock switch. (In this condition, the monitor 
switch contacts are opened.)
When oven is plugged in, 120 volts A.C. is supplied to the 
control unit. (Page 10).

1.  The display will show flashing "Enjoy Your Drawer Touch 

Clear and Touch Clock".

 

To set any program or set the clock, you must first touch 
the STOP/CLEAR pad. The display will clear, and "  :  " 
will appear.

COOKING CONDITION

Program desired cooking time by touching the NUMBER 
pads. Program the power level by touching the POWER 
LEVEL pad and then a Number pad.
When the START pad is touched, the following operations 
occur:

1.  The contacts of relays are closed and components 

connected to the relays are turned on as follows.

 

(For details, refer to Page 10)

 

RELAY  

CONNECTED COMPONENTS

 

RY-1  

Oven lamp/stir fan motor/fan motor

 

RY-2  

Power transformer

 

RY-3 

Stirrer motor

 

RY-4 

Fan motor

2.  120 volts A.C. is supplied to the primary winding of the 

power transformer and is converted to about 3.3 volts 
A.C. output on the filament winding, and approximately 
2370 volts A.C. on the high voltage winding.

3. The filament winding voltage heats the magnetron 

filament and the H.V. winding voltage is sent to a voltage 
doubler circuit.

4.  The microwave energy produced by the magnetron is 

channelled through the waveguide into the cavity feed-
box, and then into the cavity where the food is placed 
to be cooked.

5. Upon completion of the cooking time, the power 

transformer, oven lamp, etc. are turned off, and the 
generation of microwave energy is stopped. The oven 
will revert to the OFF condition.

6.  When the drawer is opened during a cook cycle, the 

monitor switch, door sensing switch, secondary interlock 
switch, relay (RY1) and primary interlock relay are 
activated with the following results. The circuits to the stir 
fan motor, the cooling fan motor, and the high voltage 
components are de-energized, the oven lamp remains on, 
and the digital read-out displays the time still remaining 
in the cook cycle when the door was opened.

7.  The monitor switch electrically monitors the operation of 

the secondary interlock switch and secondary interlock 
relay and is mechanically associated with the drawer so 
that it will function in the following sequence.

8.  When the drawer opens from the closed position, the 

primary interlock relay (RY2) and secondary interlock 
switch open their contacts. And contacts of the relay 
(RY1) remains closed. Then the monitor switch contacts 
close. 

9.  When the drawer is closed from the open position, the 

monitor switch contacts open first. Then the contacts of 
the secondary interlock switch and door sensing switch 
close. And contacts of the relay (RY1) open.

If the secondary interlock switch and primary interlock 
relay (RY2) fail with the contacts closed when the drawer 
is opened, the closing of the monitor switch contacts will 
form a short circuit through the  fuse, secondary interlock 
switch, relay (RY1) and secondary interlock relay (RY2), 
causing the  fuse to blow.

POWER LEVEL P-0 TO P-90 COOKING

When Variable Cooking Power is programmed, the 120 
volts A.C. is supplied to the power transformer intermittently 
through the contacts of relay (RY-2) which is operated by 
the control unit within a 32 second time base. Microwave 
power operation is as follows:

 

VARI-MODE  

ON TIME   

OFF TIME

 

Power 10(P-HI)  

32 sec.  

0 sec.

 

(100% power)   

 

Power 9(P-90)       

30 sec.  

2 sec.

 

(approx. 90% power)      

  

 

Power 8(P-80)       

26 sec.  

6 sec.

 

(approx. 80% power)

    Power 7(P-70)       

24 sec.  

8 sec.

 

(approx. 70% power)    

  

 

Power 6(P-60)       

22 sec.  

10 sec.

 

(approx. 60% power)      

  

 

Power 5(P-50)       

18 sec.  

14 sec.

 

(approx. 50% power) 

   

  

 

Power 4(P-40)       

16 sec.  

16 sec.

 

(approx. 40% power) 

  

 

Power 3(P-30)       

12 sec.  

20 sec.

 

(approx. 30% power)

   Power 2(P-20)       

 8 sec.  

24 sec.

 

(approx. 20% power) 

   

     

 

Power 1(P-10)       

 6 sec.  

26 sec.

 

(approx. 10% power) 

   

    

 

Power 0(P-0)       

 0 sec.  

32 sec.

 

(0% power) 

  

 

      

  

Note:  The ON/OFF time ratio does not correspond with the 

percentage of microwave power, because approx. 2 
seconds are needed for heating of the magnetron 
filament.

Summary of Contents for Microwave Drawer SMD3070ASY

Page 1: ...ervice only The contents are subject to change without notice SHARP ELECTRONICS CORPORATION SMD2470ASY SMD3070ASY In the interest of user safety the unit should be restored to its original condition and only parts identical to those specified should be used WARNING TO SERVICE PERSONNEL This service manual is intended for use by persons having electrical and mechanical training and a level of knowl...

Page 2: ...on and transmission systems shall be repaired replaced or adjusted by procedures described in this manual before the oven is released to the owner e A microwave leakage check to verify compliance with the Federal Performance Standard should be performed on each oven prior to release to the owner BEFORE SERVICING Before servicing an operative unit perform a microwave emission check as per the Micro...

Page 3: ...move neccessary covers 2 Open the drawer and keep it open 3 Discharge high voltage capacitor 4 Disconnect the leads to the primary of the power transformer 5 Ensure that the leads remain isolated from other components and oven chassis by using insulation tape 6 After that procedure reconnect the power supply cord When the testing is completed 1 Disconnect the power supply cord and then remove cove...

Page 4: ...ainer shall be a low form of 600 ml 20 oz beaker with an inside diameter of approx 8 5 cm 3 1 2 in and made of an electrically nonconductive material such as glass or plastic The placing of this standard load in the oven is important not only to protect the oven but also to insure that any leakage is measured accurately 3 Set the cooking control on Full Power Cooking Mode 4 Close the drawer and se...

Page 5: ... not defective C The door packing is not damaged D The door is not deformed or warped E There is not any other visible damage with the oven Servicing and repair work must be carried out only by trained service personnel DANGER Certaininitialpartsareintentionallynotgroundedandpresent a risk of electrical shock only during servicing Service personnel Do not contact the following parts while the ap p...

Page 6: ... Complement Touch Control System Clock 1 00 12 59 Timer 0 99 min 99 seconds Microwave Power for Variable Cooking Repetition Rate P HI Full power throughout the cooking time P 90 approx 90 of Full Power P 80 approx 80 of Full Power P 70 approx 70 of Full Power P 60 approx 60 of Full Power P 50 approx 50 of Full Power P 40 approx 40 of Full Power P 30 approx 30 of Full Power P 20 approx 20 of Full P...

Page 7: ...act a qualified electrician and have it replaced with a properly grounded three pronged wall receptacle or have a grounding adapter prop erly grounded and polarized If an extension cord must be used it should be a 3 wire 15 amp or higher rated cord Do not drape over a counter top or table where it can be pulled on by children or tripped over accidentally NOTE The directed features are disabled aft...

Page 8: ...g results The circuits to the stir fan motor the cooling fan motor and the high voltage componentsarede energized theovenlampremainson and the digital read out displays the time still remaining in the cook cycle when the door was opened 7 The monitor switch electrically monitors the operation of the secondary interlock switch and secondary interlock relay and is mechanically associated with the dr...

Page 9: ...e power Cooking Sequence 1 Touch one of the SENSOR pads NOTE The oven should not be operated on sensor immediately after plugging in the unit Wait two minutes before cooking on SENSOR 2 The coil of shut off relay RY 1 is energized but the power transformer is not turned on 3 After about 16 seconds the cook relay RY 2 is energized The power transformer is turned on microwaveenergyisproducedandfirst...

Page 10: ...ONITOR SWITCH PRIMARY INTERLOCK RELAY RECTIFIER MAGNETRON POWER TRANSFORMAR CAPACITOR 1 00μF AC 2300V STIRRER MOTOR L N A7 A5 A1 A3 C 1 C 5 CN201 1 CN101 1 CN101 3 CN201 2 CONTROL UNIT N 1 N 2 N 3 N 4 N 5 N 6 N 7 N 8 SWITCHING REGULATOR CIRCUITS SUBJECT TO CHANGE WITHOUT NOTICE OVEN THERMAL CUT OUT MG THERMAL CUT OUT SECONDARY INTELOCK SWITCH DM MICROWAVE DRAWER DOOR OPEN CLOSE MOTOR R Y 4 DOOR SE...

Page 11: ...enever troubleshooting is performed with the power supply cord disconnected It may in some cases be necessary to connect the power supply cord after the outer case has been removed in this event 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 th...

Page 12: ...pear in display Oven seems to be operating but little or no heat is produced in oven load Food incompletely cooked or not cooked at all at end of cook cycle AH sensor does not end during sensor cooking condition Oven does not shut off after a cup of water is boiling by sensor cooking TEST PROCEDURE REFERENCE LETTER SECONDARY THIRD INTERLOCK SWITCH PRIMARY THIRD OR STOP SWITCH E Q ...

Page 13: ...s 2 Open the drawer and block it open 3 Discharge high voltage capacitor 4 Replace the Key Unit and or Hidden Control Panel Hinge Assembly 5 Reconnect all leads removed from components during testing 6 Re install the covers 7 Reconnect the power supply cord after the covers are installed 8 Run the oven and check all functions 2 Control Unit The following symptoms indicate a defective control unit ...

Page 14: ...rmer RY3 Approx 26V D C Stirrer motor RY4 Approx 26V D C Fan motor 8 Disconnect the power supply cord and then remove outer case 9 Open the door and block it open 10 Discharge high voltage capacitor 11 Reconnect all leads removed from components during testing 2 Open the drawer and block it open 3 Discharge high voltage capacitor 4 If the display fails to clear when the STOP CLEAR pad is depressed...

Page 15: ... Supply Check for burned damage If the varistor on Switching Power Supply has burned damage replace Switching Power Supply If the varistors on Noise Unit has burned damage replace Noise Filter Unit 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 functi...

Page 16: ...IMER CLOCK pad once the POWER LEVEL pad twice and the START pad once And touch the number pad 1 once and the number pad 4 once Now the oven is in the sensor cooking condition and AH20 and ON will appear in the display 5 The oven will operate for the first 16 seconds without generating microwave energy NOTE ERROR will appear if the door is opened or STOP CLEAR pad is touched during first stage of s...

Page 17: ...wer supply cord 9 Check the sensor cook operation proceed as follows 9 1 Close the door Touch the TIMER CLOCK pad once the POWER LEVEL pad twice and the START pad once And touch the number pads 1 once and the number pad 4 once 9 2 The control panel is in the sensor cooking operation 9 3 Afterapproximately25seconds pushplungerofselectswitchformorethan3seconds Thiscondition is same as judgement by A...

Page 18: ...and of a watch or the digital read out countdown 3 Remove the cup from the oven and again measure the temperature making sure to stir the thermometer or thermocouple through the water until the maximum temperature is recorded 4 Subtract the cold water temperature from the hot water temperature The normal result should be 28 ο to 54 ο F 16 ο to 30 ο C rise in temperature If the water temperatures a...

Page 19: ...eter 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 defect...

Page 20: ...O MEASURE THE FILAMENT AND HIGH VOLTAGE 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 BEFOREREPLACINGABLOWNMONITORF...

Page 21: ...will supply a forward bias voltage of more than 6 3 volts N NOISE 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 4 Disconnect the leads to the primary of the power transformer 5 Using an ohm meter check between the terminals as described in the following table MEASURING POINT INDICATION OF OHM METER Bet...

Page 22: ...he above is not the case check the capacitor with an ohmmeter to see if it is shorted between either of the terminals and case If it is shorted replace the capacitor 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 P HIGH VOLTAGE CAPACITOR TEST T...

Page 23: ...ay as to change the resistance values in parallel with R45 R49 Changing HUMIDITY SENSOR CIRCUIT the resistance values results in that there is the same potential at both F 3 terminal of the absolute humidity sensor and AN6 terminal of the LSI The voltage of AN7 terminal will indicate about 2 5V This initial balancing is set up about 16 seconds after the unit is put in the Sensor Cookingmode Asthes...

Page 24: ...parts Oven lamp Magnetron High voltage transformer and Oven cavity WARNING FOR WIRING 1 Disconnect the power supply cord 2 Make sure that a definite click can be heard when the microwave oven drawer is unlatched Hold the drawer in a closed position with one hand then pull the drawer open this causes the latch leads to rise it is then possible to hear a click as the drawer switches operate 3 Visual...

Page 25: ...unplug AC Cord from molex Fig 2 4 Remove the 18 screws holding the Control Panel Rear Cover Outer Case Side Angles then remove outer Case Fig 2 5 Remove the 10 screws holding the Back Plate NOTE You now have access to all components of the Drawer WARNING Follow all safety precautions as stated at the beginning of this Service Manual before proceeding Fig 2 MICROWAVE DRAWER DISASSEMBLY Cavity Back ...

Page 26: ... CONTROL PANEL C P REMOVAL TOP MOUNT ANGLE CPU DRAWER HIDDEN CONTROL PANEL HINGE ASSY BOTTOM MOUNT INSERT CONTROL PANEL DECORATION EPDM CUSHION CPU REMOVAL 6 With C P laying on protected surface and Hidden C P open remove 2 screws from CPU and remove board Fig 4 Fig 4 C P BREAK DOWN 7 Remove 5 screws from bottom of C P Decoration Fig 4 8 Carefully lift Hidden C P Hinge Assy with Bottom Mount Inser...

Page 27: ...he black and white AC terminals from the Noise Filter PWB plus the Red and double White terminals Fig 4 2 Remove the 1 screw holding the Noise Filter Fig 4 Fig 4 3 Reverse order to reinstall Noise Filter Unit Red Wire Double White Wire White AC Wire Black AC Wire Screw ...

Page 28: ...perly due to a misadjustment the following adjustment should be made 6 Loosen the screw holding latch hook to the oven cavity flange 7 With drawer closed adjust latch hook by moving it back and forth and up and down In and out play of the door allowed by the upper and lower position of the latch hook should be less than 0 5mm The vertical position of the latch hook should be adjusted so that the s...

Page 29: ...r to the side to release the drawer from the Slide rail by pulling it out 4 Remove 2 inside screws nuts from right or left Door Support Angle Slide Rail then remove Slide Rail Fig D 6 5 To replace Rack Gear remove Door Support Angle B from Door panel then remove 3 screws holding Rack Gear on Fig D 4 To reassemble just reverse the above order After reassembly do the following A Make sure that drawe...

Page 30: ...gned to act as an electronic seal preventing the leakage of microwave energy from oven cavity during cook cycle This function does not require that door be air tight moisture condensation tight or light tight Therefore occasional appearance of moisture light or sensing of gentle warm air movement around oven drawer is not abnormal and do not of themselves indicate a leakage of microwave energy fro...

Page 31: ... cavity angle correctly before tightening screws 2 AfterAutodrawerGearisreinstalled inserttheholecoverinreverseordersothatitcanbesecuredwithaXOTS740P12000 common screw 1 Follow the Microwave Drawer disassembly as previously stated 2 Open the drawer and keep it open 3 To discharge the high voltage capacitor wait for 60 seconds 4 Remove the Microwave Drawer by following steps under DRAWER SUPPORT AN...

Page 32: ...UPPLY 1 2 3 4 5 BLK RED CNC RY1 N O RY1 COM RY2 N O RY2 COM 7 6 5 4 3 2 1 BLK RED BRN CNA BLK ORG BLK RED WHT RED 1 2 3 CN101 GRY RED GRN 1 2 3 4 5 BLU WHT RED CNN ORG 1 2 3 4 5 6 7 WHT WHT CNK 8 WHT WHT WHT WHT WHT WHT 1 2 3 4 5 6 7 WHT WHT WHT CNH 9 8 10 WHT WHT WHT WHT WHT WHT 1 2 3 4 5 BLU WHT RED DC MOTOR ORG GRN GRY WHT WHT GRN GRN GRN GRY CN H CN A COM N O RY1 RY2 POWER SUPPLY CN F COM N O ...

Page 33: ...ASSY SMD3070ASY 1 BS 3 3 PMAG B002MRE0A MAGNETIC STRIP 1 AD 3 4 PMAG B003MRE0A ROUND MAGNET 2 AF 3 5 XEPS730P10XS0 M3 X 10 SCREW STEEL P TIGHT 2 AC 3 6 LX CZB066MRE0 Screw 4 x 1 3 Flathead SS 2 AA 3 7 LX WZB040MRE0 O Ring 4mmID Rubber 2 AA 3 8 PCUSGB116MRP0 CUSHIONS 2 AB 3 9 FHNG B058MRY0 CP HINGE ASSY LEFT 1 AH 3 10 FHNG B057MRY0 CP HINGE ASSY RIGHT 1 AH 3 11 LX CZB060MRE0 Screw 8 18 3 8 PHILLIPS...

Page 34: ...W TAP PAN HEAD 11 AA 5 9 GCOVHB067MRF0 CHOKE COVER SMD2470ASY 1 AY 5 9 GCOVHB076MRF0 CHOKE COVER SMD3070ASY 1 AM MISCELLANEOUS 6 1 TINSEB538MRR0 OP MANUAL ASSY 1 AE 6 2 TINSEB539MRR0 INSTALLATION INSTRUCTIONS 1 AA 6 3 LX CZB055MRE0 WOOD SCREW M4 X 20 PANHEAD 4 AA 6 4 TCAUAA387WRRZ DHHS GRD CAUTION LABEL 1 AD 6 5 TCAUAB050MRR0 MONITOR CAUTION LABEL 2 AD 6 6 TCAUAB059MRR0 CONSUMER WARNING LABEL 1 AA...

Page 35: ...5 SMD2470ASY SMD3070ASY 6 4 5 1 2 3 6 4 5 1 2 3 A B C D E F G H A B C D E F G H 3 11 3 1 3 13 3 16 3 7 3 9 3 11 3 5 3 11 3 10 3 11 3 15 3 4 3 6 3 4 3 6 3 8 3 8 3 3 3 7 3 5 3 12 3 8 3 8 3 14 3 11 3 11 3 2 ...

Page 36: ...D2470ASY SMD3070ASY 6 4 5 1 2 3 6 4 5 1 2 3 A B C D E F G H A B C D E F G H DRAWER 4 2 4 6 4 6 5 9 5 6 5 8 5 4 5 7 5 5 5 5 5 7 5 8 5 1 5 3 5 8 5 8 6 6 5 11 5 11 5 10 5 2 NOTE Screws 5 8 not included with 5 2 ...

Page 37: ...7 9 4 11 4 28 4 21 1 15 7 2 7 4 1 1 4 20 1 12 4 10 7 1 7 10 7 13 7 13 4 7 7 13 7 13 7 1 X4 1 16 7 3 7 3 7 5 4 14 7 5 7 8 4 9 4 25 4 13 7 13 7 11 4 17 4 15 4 15 4 23 4 4 4 30 4 33 4 32 4 29 7 2 7 4 1 8 1 15 4 18 7 13 1 9 7 13 7 13 1 10 7 10 1 11 7 7 1 11 7 7 7 1 7 13 4 1 4 8 7 6 7 8 X2 4 13 7 13 7 12 1 2 7 13 1 3 4 12 Knockout for Auto Drawer Gear Replacement 6 4 6 5 6 5 6 7 6 8 Actual wire harness...

Page 38: ... 2 3 6 4 5 1 2 3 A B C D E F G H A B C D E F G H Knockout for Oven lamp Replacement 2 4 7 13 7 13 7 13 7 13 2 2 1 4 2 5 7 13 7 13 7 13 7 13 2 1 6 10 7 13 2 6 7 8 7 8 6 3 2 3 6 3 2 3 7 8 2 4 SMD3070AS 7 8 SMD3070AS SMD2470AS SMD2470AS 7 13 7 13 4 16 ...

Page 39: ...CKING PARTS INSTALLION SHEET OPERATION MANUAL WOOD SCREWS 6 3 6 1 6 2 SUPPORT CORNERS Non replaceable items TOP FOAM SUPPORT CORNERS BOTTOM FOAM SUPPORT CORNERS SUPPORT CORNERS TOP FOAM PACKING CASE DRAWER SUPPORTS CROSS SUPPORTS ...

Page 40: ... CORPORATION ALL RIGHTS RESERVED Nopartofthispublicationmaybereproduced stored in retrieval systems or transmitted in any form or by any means electronic mechanical photocopying recording or otherwise without prior written permission of the publisher ...

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