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MMDV30S MMDH30S SERVICE MANUAL

Contents

1. MMDV30S MMDH30S 1 2 3 4 5 6 A A 5 Power Supply cord 120V 60Hz NOISE FILTER BOARD to Back Plate CN502 B B SWITCHING POWER SUPPLY CN501 MAGNETRON OVEN THERMAL THERMAL CUT OUT CUT OUT CNA WHT WHT RED N C BLK THIRD DOOR SWITCH MONITOR COOLING SWITCH FAN UD CNB MOTOR N RY1 N O RY1 POWER SUPPLY STIRRER D MOTOR 8 5 E CN H 3 INTERLOCK 2 199 SWITCH 8 ha H 9 OVEN LAMP 9 CN A 8 7 CNH 6 5 CONTROL UNIT 4 3 REAR 20 0 5 ACTUATOR 7 SWITCH HIGH VOLTAGE COMPONENTS MAGNETRON 5 8 4 HIGH VOLTAGE El 5 CAPACITOR 2 HIGH VOLTAGE 8 1 WIRE 1 ACTUATOR F 4 SWITCH m CNN 3 2 1 POWER UL TRANSFORMER REGTIFIER CNM El 8 onk 8 0 STOP SWITCH 6 G 5 G O o 4 3 2 1 H H Figure S 1 Pictorial Diagram 1 2 3 4 5 6 35 MMDV30S MMDH30S 4 3 4 5 CN A T1
2. 18 NOULINOVW MMDV30S MMDH30S SALON 33 113 1510 YC JAVMOYDIW PE AND INOW HOLIMS 77 v HJLIMS NOILISOd 504 ONISNAS 2 ooa _ 35012 3 0 gt 2 2 a m A 255 2 zje 52 5 gt no Eu 19 7 0 gf YOLVINDAY 1185 2 6H 20582 5 lt A 115 22 axe S LINN 104102 3 2 T 340 00 1 a 2 m ee lt 97 10662 1 0 0 Ale 5 NUD ify Ane 25 22 t 3 lt lt 5 5 lo S i 9179 5 ASIE 1938 1HM 5 5 1 glg 20 les 16 5 oe 15 110 7 52 x e 18 a wn a a 29 g
3. L ASO dWX 150 NND OL ma NYS L IHM 1 689416 dWY WND OL 33 MICROWAVE DRAWER WIRING DIAGRAM MMDV30S MMDH30S 410 115 27 yadan 805 SND OL VND SMOL 5 woo AYVONODAS IHM 5 88 5 25 WoD Nug L 1840 MU WoD 8 8 KA so aay esas 580 DUO Ju AH adan MOT X19410 034 Imm M INON ma 94010 o YOLWINDIY 5 OL OL 9 ISION ON Woo MS HOLINOW 34
4. C45 0 01pF 64 R43 1 8K R44 360K R51 47K R45 620K 52 SW1 R46 300K 51 sw2 R47 150K 50 SW3 R48 75K 49 sw4 R3 Absolute humidity vs output voltage characteristic R49 37 4 Operational R1 amplifier Output voltage Output voltage S Thermistor open vessel C Thermistor closed vessel Absolute humidity g m2 3 Detector Circuit of Humidity Sensor Circuit This detector circuit is used to detect the output voltage of the absolute humidity circuit to allow the LSI to control sensor cooking of the unit When the unit is set in the sensor cooking mode 16 seconds clearing cycle occurs than the detector circuit starts to function and the LSI observes the initial voltage available at its AN6 terminal With this voltage given the switches SW1 to SW5 in the LSI are turned on in such a way as to change the resistance values in parallel with R45 R49 Changing 23 MMDV30S MMDH30S TOUCH CONTROL PANEL SERVICING Precautions for Handling Electronic Components This unit uses CMOS LSI in the integral part of the circuits When handling these parts the following precautions should be strictly followed CMOS LSI have extremely high impedance at its input and output terminals For this reason it is easily influenced by the surrounding high voltage power source static electricity charge in clothes etc and sometimes it i
5. 3 Re connect the leads to the primary of the power transformer 4 Re install the outer case cabinet 5 Re connect the power supply cord after the outer case is installed 6 Run the oven and check all functions 24 A On some models the power supply cord between the touch control panel and the oven itself is so short that the two can t be separated For those models check and repair all the controls sensor related ones included of the touch control panel while keeping it connected to the oven B On some models the power supply cord between the touch control panel and the oven proper is long enough that they may be separated from each other For those models it is possible to check and repair the controls of the touch control panel while keeping it apart from the oven proper in this case you must short both ends of the door sensing switch on PWB of the touch control panel with a jumper which activates an operational state that is equivalent to the oven door being closed As for the sensor related controls of the touch control panel checking them is possible if dummy resistor s with resistance equal to that of the controls are used 2 Servicing the touch control panel with power supply from an external power source Disconnect the touch control panel completely from the oven proper and short both ends of the door sensing switch on PWB of the touch control panel which activates an operational state tha
6. 4 FOREWORD AND WARNING 5 PRODUCT SPECIFICATIONS SCHEMATICS 10 TEST PROCEDURES feces tas sa 11 TOUCH CONTROL ASSEMBLY 19 MICROWAVE DRAWER 8 27 WIRING DIAGRAMS ade 33 PRINTED WIRING BOARDS NAERA AEEA ETEEN REANA 36 PARTS EIS 40 PACKING AND ACCESSORIES EENEN 45 This document has been published to be used for after sales service only The contents are subject to change without notice distinctive appliances MMDV30S MMDH30S PRECAUTIONSTO BE OBSERVED BEFORE AND DUR ING SERVICING TO AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY a Do not operate or allo
7. 5101084 89 9 01 10 ASE ANOL 90 9 2 ASE 4NOL _ waans Ave SAu MS na ws MS SOd woo 88010 EMS 304 1 SOd 30 3 HV INI yz 2201014 2x 002 9 59 YA lt 37 EMS 15 1 Figure 5 4 Printed Wiring Board of Power Unit N MMDV30S MMDH30S 90 201 3 oey ES 808 8013 8 1012 0015 214 2012 1431 010 0 498 EZY 024 868 128 veS LCD 05 20 1 2 9 8 03 7 889 se mlo re mo 5855 Fla Sn Ag Cu 07 3 CNE R40 655 1 WHA TE 1 6 CNN 38 T 2 1 12 1 1 1 5 Figure 5 5 Printed Wiring Board of Contro
8. LETTER 9 2 Place the container on the center of tray in the oven cavity 9 3 Close the drawer 9 4 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 5 The control panel is in automatic Sensor operation 9 6 The oven turns off automatically and the time for detecting moisture will be displayed If new sensor does not operate properly the problem is with the control unit and refer to explanation be low CHECKING CONTROL UNIT 1 Disconnect the power supply cord and then disassemble as per MICROWAVE DRAWER DISASSEMBLY page 25 Open the drawer and block it open Discharge high voltage capacitor Disconnect the sensor connector that is mounted to control panel Then connect the dummy resistor circuit see fig to the sensor connector of control panel Disconnect the leads to the primary of the power transformer Ensure that these leads remain isolated from other components and oven chassis by using insulation tape 8 After that procedure re connect the power 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 After approximately 25 seconds push plunger of select switch for more than 3 seconds T
9. Key strobe signal Signal applied to touch key section A pulse signal is input to P20 P23 terminal while one of J 9 line key on matrix is touched Key strobe signal Signal applied to touch key section A pulse signal is input to P20 P23 terminal while one of J 8 line key on matrix is touched Key strobe signal Signal applied to touch key section A pulse signal is input to P20 P23 terminal while one of J 7 line key on matrix is touched Key strobe signal Signal applied to touch key section A pulse signal is input to P20 P23 terminal while one of J 6 line key on matrix is touched Key strobe signal Signal applied to touch key section A pulse signal is input to P20 P23 terminal while one of J 5 line key on matrix is touched Fan motor Drawer driving signal To turn on and off relay RY4 level During fan motor ON L level During fan motor OFF Stirrer motor driving signal To turn on and off relay RY3 level During fan motor L level During fan motor OFF 21 MMDV30S MMDH30S Magnetron high voltage circuit driving signal licrowave cooking mode Other cooking mode To turn on and off the cook relay RY2 In 100 ON TIME OFF TIME ON TIME OFF TIME power operation the signals holds level during microwave cooking and L level while not cooking 80 powe
10. On Off Cotrol Lock Reheat Oven Cavity Light Yes Safety Standard UL Listed FCC Authorized DHHS Rules CFR Title 21 Chapter 1 Subchapter J ca GENERAL INFORMATION MMDH30S GROUNDING INSTRUCTIONS This oven is equipped with a three prong grounding plug It must be plugged into a wall receptacle that is properly installed and grounded in accordance with the National Electrical Code and local codes and ordinances In the event of an electrical short circuit grounding reduces the risk of electric shock by providing an escape wire for the electric current WARNING Improper use of the grounding plug can result in a risk of electric shock Electrical Requirements The electrical requirements are a 120 volt 60 Hz AC only 15 or 20 amp fused electrical supply It is recommended that a separate circuit serving only this appliance be provided When installing this appliance observe all applicable codes and ordinances Where a two pronged wall receptacle is encountered it is the personal responsibility and obligation of the customer to contacta qualified electrician and have it replaced with a properly grounded three pronged wall receptacle or have a ground ing adapter properly grounded and polarized If the extension cord must be used it should be a 3 wire 15 amp or higher rated cord Do not drape over a countertop or table where it can be pulled on by children or tripped over accidentally CAUTION DO NOT UNDER ANY CIRCUMSTANCE
11. and the oven is fully assembled the microwave power output should be checked and a microwave leakage test should be carried out MMDV30S MMDH30S MICROWAVE MEASUREMENT PROCEDURE A Requirements 1 Microwave leakage limit Power density limit The power density of microwave radiation emitted by a microwave oven should not exceed 1mW cm at any point 5cm or more from the external surface of the oven measured prior to acquisition by a purchaser and thereafter through the useful life of the oven 5 mW cm at any point 5cm or more from the external surface of the oven Safety interlock switches Primary interlock relay switch shall prevent microwave radiation emission in excess of the requirement as above mentioned Secondary interlock relay and door sensing switch shall prevent microwave radiation emission in excess of 5 mW cm2 at any point 5cm or more from the external surface of the oven Preparation for testing Before beginning the actual measurement of leakage proceed as follows 1 Make sure that the actual instrument is operating normally as specified in its instruction booklet Important Survey instruments that comply with the requirement for instrumentation as prescribed by the performance standard for microwave ovens 21 CFR 1030 10 c 3 i must be used for testing 2 Place the load of 275 15 ml 9 8 oz of tap water initially at 20 5 68 F the center of the oven cavity The water container shall
12. current Contact with the following parts may result in severe possibly fatal electric shock Example High Voltage Capacitor Power Transformer Magnetron High Voltage Rectifier Assembly High Voltage Harness etc To Avoid possible exposure to microwave energy please follow the instructions below before operating the oven 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 Drawer does not close firmly Drawer latch hook is damaged The drawer gasket or seal is damaged The drawer is bent or warped There are defective parts in the drawer interlock is then possible to hear click as the drawer switches system operate 6 There are defective parts in the microwave generating 3 Visually check the drawer and cavity face plate for and transmission assembly damage dents cracks signs of arcing etc 7 There is visible damage to the oven Carry out any remedial work that is necessary before Do not operate the oven operating the oven 1 Without the RF gasket Magnetron Do not operate the oven if any of the following conditions 2 If the wave guide or oven cavity are not intact exist 3 If the drawer is not closed WARNING FOR WIRING To prevent an electric shoc
13. the water until the temperature stabilizes Record the temperature of the water 2 Place the cup of water in the oven Operate oven at POWER 10 HIGH selecting more than 60 seconds cook time Allow the water to heat for 60 seconds measuring with a stop watch second hand 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 to 54 F 16 to 30 C rise in temperature If the water temperatures are accurately measured and tested for the required time period the test results will indicate if the magnetron tube has low power output low rise in water temperature which would extend cooking time or high power output high rise in water temperature which would reduce cooking time Because cooking time can be adjusted to compensate for power output the magnetron tube assembly should be replaced only if the water temperature rise test indicates a power output well beyond the normal limits The test is only accurate if the power supply line voltage is 120 volts and the oven cavity is clean THERMAL CUT OUT 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 A continuity check across the the
14. 20sec 40 20sec 30 45sec 5 If improper operation is indicated the control unit is probably defective and should be checked E PROCEDURES 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 60 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 le
15. CH ANGLE REMOVAL ADJUSTMENT WITCH ANGLE REMOVAL Fig S 1 Locate either the right or left switch angle Follow the Microwave Drawer disassembly as previously stated Open the drawer and keep it open To discharge the high voltage capacitor wait for 60 seconds To remove switch remove screw 1 holding switch to switch angle Fig S 1 RON 5 To replace switch angle remove bottom cover and remove the 2 screws holding the switch lever Fig S 2 6 Proceed in reverse to reinstall 7 Adjust switch ACTUATOR REMOVAL ADJUSTMENT Follow the Microwave Drawer disassembly as previously stated Open the drawer and keep it open To discharge the high voltage capacitor wait for 60 seconds Locate either the right or left actuator and remove the 2 screws holding the actuator to the door support angles 5 Relpace with the new actuator Fig A 3 RON Actuator adjustment 6 Itis very critical that proper adjustment is made to actuator 7 Adjust each actuator to fully depress 0 gap switch lever switches on left and right side Fig 4 NOTE If this adjustment is not adjusted correctly it will effect the performance of the Auto Drawer Fig A 4 MMDV30S MMDH30S DRAWER GEAR REMOVAL Follow the Microwave Drawer disassembly as previously stated Open the drawer and keep it open To discharge the high voltage capacitor wait for 60 seconds Unhook w
16. E MANUAL distinctive appliances PRODUCT DESCRIPTION MICROWAVE DRAWER MMDV30S MMDH30S SCHEMATICS FOREWORD This Manual has been prepared to provide Dacor Service Personnel with Operation and Service Information for the DACOR MICROWAVE TEST PROCEDURE DRAWER MMDV30S and 5 It is recommended that service personnel carefully study the entire text of this manual so that they will be qualified to render satisfactory TOUCH CONTROL PANEL customer service Check the interlock switches and the door seal carefully Special attention should be given to avoid electrical shock and microwave MICROWAVE DRAWER radiation hazard DISSASSEMBLY AND ADJUSTMENT PROCEDURE WARNING Never operate the oven until the following points are ensured A The door is tightly closed B The door brackets and hinges are not defective C The door packing is not damaged D The door is not deformed or warped E There is no other visible damage with the oven WIRING DIAGRAM PARTS LIST Servicing and repair work must be carried out only by trained service personnel DANGER Certain initial parts are intentionally not grounded and present a risk of electrical shock only during servicing Service personnel Do not contact the following parts while the ap pliance is energized Inverter unit that includes High Voltage Capacitor High Volt age Power Transformer High Voltage Rectifier Heat sink etc and Magnetron High Vol
17. ONS of the operation manual 4 Exhaust vents are provided on the back of the unit for proper cooling and air flow in the cavity To permit adequate ventilation be sure to install so as not to block these vents There should be some space for air circulation 5 Be sure the exterior of the cooking container and the interior of the oven are dry Wipe off any moisture with a dry cloth or paper towel 6 The Sensor works with food at normal storage temperature For example chicken pieces would be at refrigerator temperature and canned soup at room temperature 7 Avoid using aerosol sprays or cleaning solvents near the oven while using Sensor settings The sensor will detect the vapor given of by the spray and turn off before food is properly cooked 8 If the sensor has not detected the vapor of the food ERROR will appear and the oven will shut off Water load cooking test WARNING The oven should be fully assembled before following procedure Make sure the oven has been plugged in at least two minutes before checking sensor cook operation The cabinet should be installed and screws tightened 1 Fill approximately 200 milliliters 7 2 02 of tap water a 1000 milliliter measuring cup 2 Place the container on the center of tray in the oven cavity 3 Close the drawer 4 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 Now the
18. PA154DR D1 D4 3 5 1N4002L x4 A 120V 60Hz 848 8 Eia GND K 3 NT K 2 SW Reg PWR K 8 502 3 SW Reg OUT E 3 D MICRO K 4 E COM O L lt NOTE gt E 14 NOT SPECIFIED 155270 NOT INSERT PARTS CHECK POINTS G SM K 5 FM K 7 H Figure S 2 Power Unit Circuit 3 36 4 5 a MMDV30S MMDH30S HUN 2 5 4 35010 440 NO aise 5 5 ZHN 240 ZZHQZELWSCO1Y 16 5 5 X009 5 5 2 lt 5 aol lt TOHULNOO gt ASL 1 ASL Ged 1 01 2201914 10 SLNIOd MOAHO SLHYd LYSSNI LON dIHO SSESSL 4 dIHO P MOL L 131519395 LON 41 lt 310 gt SOLOW 08 70 0 0 9 2 50 ASE ANOL 10 0 480 860 001 568 oor 960 8 01083 SLOLOUM 520 5 01087 5 01087 zzo ozz 120 eeu ASE 4NOL 120
19. S CUT OR REMOVE THE ROUND GROUNDING PRONG FROM THIS PLUG Grounded Receptacle Box 3 Pronged Plug Grounding Pin 3 Pronged Receptacle KEY SHEET SENSOR SENSOR SENSOR START POWER POPCORN REHEAT COOK LEVEL 012101010 MICRO TIMER DEFROST REHEAT CLEAR The directed features are disabled after one minute when the oven is use These features are automatically enabled when the door is opened and closed or the STOP CLEAR pad is pressed MMDV30S MMDH30S 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 8 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 Pa
20. 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 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 K MONITOR SWITCH TEST Disconnect the power supply cord Open the drawer and keep it open To discharge high voltage capacitor wait for 60 seconds 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 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 i
21. ads 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 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 MMDV30S MMDH30S TEST PROCEDURES eae COMPONENT TEST 11 Discharge high voltage capacitor 12 Reconnect all leads removed from components during testing 13 Re install the outer case cabinet 14 Reconnect the power supply cord after the outer case is installed 15 Run the oven and check all functions F AH SENSOR TEST Checking the initial sensor cooking condition WARNING The oven should be fully assembled before following procedure 1 The oven should be plugged in at least two minutes before sensor cooking 2 Room temperature should not exceed 95 F 35 C 3 The unit should not be installed in any area where heat and steam are generated The unit should not be installed for example next to conventional surface unit Refer to the INSTALLATION INSTRUCTI
22. arts to detect the initial voltage at AN7 terminal 16 seconds after the unit has been put in the Sensor Cooking mode if it is not possible to balance the bridge circuit due to disconnection of the absolute humidity sensor ERROR will appear on the display and the cooking is stopped metal mesh to be protected from the external airflow ventilation opening for sensing Sensing part Open vessel Sensing part Closed vessel 2 Operational Principle of Humidity Sensor The figure below shows the basic structure of an absolute humidity sensor A bridge circuit is formed by two thermistors and two resistors R1 and R2 The output of the bridge circuit is to be amplified by the operational amplifier 38 5a pJ Each thermistor is supplied with a current to keep itheated at about 150 C 302 F the resultant heat is dissipated 86 in the air and if the two thermistors are placed in different gt humidity conditions they show different degrees of heat conductivity leading to a potential difference between them causing an output voltage from the bridge circuit the intensity of which is increased as the absolute humidity of the air increases Since the output is varied every minute it is amplified by the operational amplifier VA 15V 45V 1 53 13 R5010K 52 47 5 C43 0 1 LSI C44 0 01 IC1
23. as been removed in this event LP 2 4 Disconnect the power supply and then remove necessary covers Open the drawer and keep it open Discharge high voltage capacitor Disconnect the leads to the primary of the power transformer Ensure that the leads remain isolated from other components and oven chassis by using insulation tape After that procedure reconnect the power supply cord When the testing is completed 1 Disconnect the power supply cord and then remove covers Open the drawer and keep it open Discharge high voltage capacitor Reconnect the leads to the primary of the power transformer Reinstall the covers Reconnect the power supply cord Run the unit and check all functions After repairing Reconnect all leads removed from components during testing Reinstall the covers Reconnect the power supply cord Run the oven and check all functions Microwave ovens should not be operated empty To test for the presence of microwave energy within a cavity place a cup of cold water on the oven tray close the drawer and set the power to HIGH and set the microwave timer for two 2 minutes When the two minutes has elapsed timer at zero carefully check that the water is now hot If the water remains cold carry out Before Servicing procedure and re examine the connections to the component being tested When all service work is completed
24. be low form of 600 ml 20 02 beaker with an inside diameter of approx 8 5 cm 3 1 2 and made of an electrically non conductive 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 select a cook cycle of several minutes If the water begins to boil before the survey is completed replace it with 275 ml of cool water C Leakage test Closed drawer leakage test microwave measurement 1 Grasp the probe of the survey instrument and hold it perpendicular to the gap between the drawer and the body of the oven 2 Move the probe slowly not faster than 1 in sec 2 5 cm sec along the gap watching for the maximum indication on the meter 3 Check for leakage at the drawer screen sheet metal seams and other accessible positions where the continuity of the metal has been breached eg around the switches indicator and vents While testing for leakage around the drawer pull the drawer away from the front of the oven as far as is permitted by the closed latch assembly 4 Measure carefully at the point of highest leakage and make sure that the highest leakage is no greater than 4mW cm and that the primary interlock switch secondary interlock relay does turn the oven OFF before any door movement MMDV30S MMDH30S SERVIC
25. cuit The power source synchronizing signal is available in order to compose a basic standard time in the clock circuit It accompanies a very small error because it works on commercial frequency 10 Door Sensing Switch Microwave drawer A switch to tell the LSI if the drawer is open or closed 11 Door Position Switch Front Rear The switch to tell the position of the Microwave drawer door 12 Back Light Circuit A circuit to drive the back light Light emitting diodes LD1 LD3 Humidity Sensor Circuit This circuit detects moisture of the cooking food to allow its automatic cooking 13 14 Microwave drawer door open close Circuit A circuit to drive the microwave drawer door open close motor MMDV30S MMDH30S DESCRIPTION OF LSI IC 1 The I O signal of the LSlis detailed the following table Terminal to change cooking input according to the Model By using A D converter contained in the LSI DC voltage in accordance with the Model in operation is applied to set up its cooking constant Input signal which inform the drawer door is in the middle position between the opened position and the closed position to LSI from the door position switch rear Turminal not used Turminal not used Power source voltage GND VC voltage of power source circuit input Connected GND Auto clear terminal Signal is input to reset the LSI to the initial state when power is appl
26. dacar SERVICE MANUAL 5 888885 MICROWAVE DRAWER MMDV30S MMDH30S MMDV30S pictured 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 knowledge of these subjects generally considered acceptable in the appliance repair trade Sharp Electronics Corporation cannot be responsible nor assume any liability for injury or damage of any kind arising from the use of this manual Microwave ovens contain circuitry capable of producing very high voltage and current Contact with the following parts may result in a severe possibly fatal electrical shock High Voltage Capacitor High Voltage Power Transformer High Voltage Rectifier and Heat sink etc and Magnetron High Voltage Harness TABLE OF CONTENTS Page PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE INSIDE FRONT COVER BEFORE SERVICING INSIDE FRONT COVER WARNING TO SERVICE 5 45 40854455 SEPEN EES 3 MICROWAVE MEASUREMENT
27. econnect the power supply cord after the covers are installed Run the oven and check all functions The following symptoms indicate a defective keyboard unit a When touching the pads a certain pad produces no signal at all b When touching a number pad two figures or more are displayed c When touching the pads sometimes a pad produces no signal If the Keyboard unit is defective 1 Disconnect the power supply cord and then remove covers 2 Open the drawer and block it open 3 Discharge high voltage capacitor 4 Replace the Keyboard unit 5 6 7 2 3 4 5 Reconnect all leads removed from components during testing Re install the covers 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 Before replacing the control unit perform the Keyboard unit test Procedure B to determine if control unit is faulty 2 1 In connection with indicators a At a certain digit all or some segments do not light up b At a certain digit brightness is low c Only one indicator does not light d The corresponding segments of all digits do not light up or they continue to light up e Wrong figure appears f A certain group of indicators do not light up g The figure of all digits flicker 2 2 Other possible problems caused by defective control unit a Buzzer does not sound or continues to sound b Clock doe
28. eparate by pulling straight forward and out Fig D 3 4 At this point you can replace either Latch Angle Assy or Latch Angles To reassemble just reverse the above order After reassembly do the following A Make sure that drawer sensing switch secondary interlock switch and monitor switch are operating properly Refer to chapter Test Procedures B An approved microwave survey meter should be used to assure compliance with proper microwave radiation emission limitation standards After any servicing make sure of the following 1 Drawer latch heads smoothly catch latch hook through latch holes and that latch head goes through center of latch hole 2 Deviation of door alignment from horizontal line of cavity face plate is to be less than 1 0mm 3 Drawer is positioned with its face pressed toward cavity face plate 4 Reassemble the unit and check for microwave leakage around Fig D 4 drawer with an approved microwave survey meter Refer to Microwave Measurement Procedure Note The drawer on a microwave oven is designed 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 movementaround oven drawer is not abnormal and do not of themselves 30 MMDV30S MMDH30S SWIT
29. g switch connecter Use the Key unit matrix SENSOR indicated on the control panel schematic and place a jumper wire 1 SENSOR Sensor SET UP between the pins that correspond to the STOP CLEAR pad making momentary contact If the control unit responds by clearing with beep WARM ON OFF the key unit is faulty and must be replaced If the control unit does not clean ERST respond it is faulty and must be replaced If a specific pad does not respond the above method may be used after clearing the control unit to determine if the control unit or key pad is at fault Reconnect all leads removed from components during testing Re install the outer case cabinet Reconnect the power supply cord after the outer case is installed Run the oven and check all functions Disconnect power supply cord and then remove outer case Open the door and block it open Discharge high voltage capacitor Disconnect the leads to the primary of the power transformer Ensure that these leads remain isolated from other components and oven chassis by using insulation tape After that procedure re connect the power supply cord Remove the outer case and check voltage between Pin Nos 5 and 7 of the 4 pin connector CN A on the power unit with an A C voltmeter The meter should indicate 120 volts if not check oven circ
30. ge 8 RELAY CONNECTED COMPONENTS RY 1 oven lamp stir fan motor fan motor RY 2 power transformer 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 secondary 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 ovenlamp 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 fo
31. he LSI are sent to the key unit from P10 P17 When a key pad is touched a signal is completed through the key unit and passed back to the LSI through P20 P23 to perform the function that was requested Control Unit and Power Unit Control unit consists of LSI IC reset circuit indicator circuit power source circuit relay circuit buzzer circuit synchro nizing signal circuit keyboard unit circuit humidity sensor circuit and back light circuit 1 1 1 LSI This is microcomputer responsible for controlling the entire control unit 2 2 This is the IC to drive the Liquid Crystal Display 3 5 This is the IC to amplify the signal from the humidity sensor 4 Reset Circuit This circuit generates a signal which resets the LSI IC 1 to the initial state when power is supplied 5 Indicator Circuit A circuit to drive the Liquid Crystal Displays LCD1 Power Source Circuit This circuit generates voltages necessary in the control unit from the AC line voltage In addition the synchronizing signal is available in order to compose a basic standard time in the clock circuit 6 Symbol Voltage 5V Application 151 101 7 Relay Circuit A circuit to drive the magnetron fan motor stirrer motor and light the oven lamp Buzzer Circuit The buzzer is responsive to signals from the LSI to emit audible sounds key touch sound and completion sound 8 9 Synchronizing Signal Cir
32. he unit out from opening and unplug the power supply cord Remove top cover Fig 2 Remove air cover from back of unit then both side cabinets Fig 2 screws 6 Remove exhaust duct and back plate Fig 2 Note When removing the back plate un hook the green ground wire terminal 2 gt Exhaust duct Right side panel Back cover Fig 2 NOTE You now have access to various components for the Drawer 27 MMDV30S MMDH30S 7 To remove the Control Panel Frame Assembly remove the 9 screws holding the C P frame to the cavity Fig 3 With the C P frame assembly now loose you can unplug all wires Fig At this point you will have access to all parts of the Microwave Drawer POWER CORD REPLACEMENT 1 Un hook the black and white AC terminals from the Noise Filter PWB Fig 4 2 Attach the black and white AC terminals from the new Power Cord to the Noise Filter as shown in figure 4 Note The green ground wire terminal can be attached when reassembling the back plate to the drawer cavity Fig 4 Back Plate 28 8 MMDV30S MMDH30S STOP SWITCH SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH REMOVAL seconds Remove the screw holding the latch hook to the oven flange 5 Remove the latch hook from the oven flange 6 7 Remove each switch from the latch hook by pushing the Disconnect the wire leads of each switch one 1 stopper tab holding each switch No
33. his condition is same as judgement by AH sensor 9 4 After approximately 3 seconds the display shows X X X X which is the time for detecting moisture If the above is not the case the control unit is probably defective If the above is proper the AH sensor is probably defective 10 Disconnect the power supply cord and then remove covers 11 Open the drawer and block it open 12 Discharge high voltage capacitor 13 Disconnect the dummy resistor circuit from the sensor connector of control panel 14 Carry out necessary repair 15 16 17 Reconnect all leads removed from components during testing and repairing Re install the covers Reconnect the power supply cord after the outer case is installed Run the oven and check all functions 18 Carry out Water load cooking test again and ensure that the oven works properly 1 2 220 1 1 2W 4 3kQ 5 1 4W R4 1MQ 5 1 4W ae Plunger NC NO To connector F on Control Unit 2 COM 1 2 F 2 lt 3 R1 9 F 3 o R22 R3 R4 MMDV30S MMDH30S PROCEDURE LETTER TEST PROCEDURES COMPONENT TEST Refer to the disassembly instructions found on Page 16 G MAGNETRON ASSEMBLY 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 To test for an o
34. ied Temporarily set to L level the moment power is applied at this time the LSI is reset Thereafter set at level Turminal not used Turminal not used Power source voltage GND VS voltage of power source circuit input Connected GND Internal clock oscillation frequency setting input The internal clock frequency is set by inserting the ceramic filter oscillation circuit with respect to Xout terminal Internal clock oscillation frequency control output Output to control oscillation input of Xin Power source voltage 5V VC voltage of power source circuit input Plus signal coming from the Microwave drawer door open close motor is input into P60 as revolution number Input signal which communicates the drawer door open information to LSI from the door position switch front Door opened level signal OV Door closed level signal 5V Signal to change the rotational direction is output to the Microwave drawer door open close motor Signal to change the rotational speed is output to the Microwave drawer door open close motor Power source to drive the Microwave drawer door open close motor is output Input terminal to check the data of display Data signal from IC 2 is input to RXD2 to check the flow of the data Output terminal to send IC 2 the data The data of display is output to IC 2 Clock timing signal output terminal Clock ti
35. input is an analog input terminal from the AH sensor circuit and connected to the A D converter built into the LSI Used for initial balancing of the bridge circuit absolute humidity sensor This input is an analog input terminal from the AH sensor circuit and connected to the A D converter built into the LSI 22 MMDV30S MMDH30S HUMIDITY SENSOR CIRCUIT 1 Structure of Humidity Sensor The humidity sensor includes two thermistors as shown in the illustration One thermistor is housed in the closed vessel filled with dry air while another in the open vessel Each sensor is provided with the protective cover made of 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 putin the Sensor Cooking mode As the sensor cooking proceeds the food is heated to generate moisture by which the resistance balance of the bridge circuit is deviated to increase the voltage available at AN6 terminal of the LSI Then the LSI observes that voltage at AN7 terminal and compares it with its initial value and when the comparison rate reaches the preset value fixed for each menu to be cooked the LSI causes the unit to stop sensor cooking thereafter the unit goes in the next operation automatically When the LSI st
36. iring Auto Drawer Gear Remove the 4 screws holding the auto drawer gear to the bottom cavity angle Fig G 1 Pull drawer gear from cavity angle The drawer gear is now free Proceed in reverse to reinstall the Auto Drawer Gear taking care that the gear teeth are set into the cavity angle correctly Fig G 1 RACK GEAR REMOVAL 1 Follow the Microwave Drawer disassembly as previously stated 2 Open the drawer and keep it open 3 4 Remove the Microwave Drawer by following steps 1 2 5 8 9 amp 10 as instructed under To discharge the high voltage capacitor wait for 60 seconds DRAWER ASSEMBLY AND CHOKE REMOVAL Remove the 3 screws holding the Rack Gear to the bottom slide rail Fig G 2 7 Proceed in reverse to reinstall the new Rack Gear Fig G 2 32 MMDV30S MMDH30S MICROWAVE DRAWER CPU WIRING DIAGRAM aad AD AND HND OL AND AWD AUD AND HM IND Nd OL gt m na MIA 8 8 aad _ 5 m N ZA 150 05 ND 5 OL WOD MIA ma
37. is opened Door sensing switch contacts open when door is opened Reassemble the unit and check for microwave leakage around door with an approved microwave survey meter Refer to Microwa ement Procedure MMDH30S DRAWER SLIDE RAIL REMOVAL ASSEMBLY AND CHOKE REMOVAL Follow the Microwave Drawer disassembly as previously NOTE stated Fig D 1 2 Open the drawer and keep it open To remove only the 3 To discharge the high voltage capacitor wait for 60 Microwave Drawer follow steps seconds 1 2 5 8 9 amp 10 as instructed under DRAWER ASSEMBLY AND CHOKE REMOVAL 4 Remove the both right and left side panels 5 Remove 2 Drawer Support Covers from Choke Cover as shown in Fig D 1 6 Insert a putty knife thickness of about 0 5mm into the gap between the choke cover and the door frame 7 Carefully slide choke cover away from drawer as far as possible 8 Remove 6 screws from all 3 drawer Support Angles as shown in Fig D 2 9 Unhook Drawer Support Angles from drawer then remove 10 Now the door assembly is free and the Choke Cover can Fig D 2 now be removed DRAWER SUPPORT ANGLE REMOVAL 1 Remove Drawer Assembly and Choke Cover as stated in DRAWER ASSEMBLY AND CHOKE REMOVAL 2 Remove 2 screws from right or left Latch Angle Assembly then remove Angle assembly Fig D 4 3 Separate Slide Rails by moving inside lever of Slide Rails The Slide Rail will now s
38. k take the following 3 Sharp edge precautions Bottom plate Oven cavity Waveguide flange 1 Before wiring Chassis support and other metallic plate 1 Disconnect the power supply cord 4 Movable parts to prevent a fault 2 Open the drawer Fan blade Fan motor Switch Switch lever Open 3 Wait 60 seconds then discharge the high voltage button capacitor 3 Do not catch the wire leads in the outer case cabinet 2 Don t let the wire leads touch to the following parts 4 Insert the positive lock connector until its pin is locked 1 High voltage parts and make sure that the wire leads do not come off Magnetron High voltage transformer High voltage even if the wire leads are pulled capacitor and High voltage rectifier assembly 5 To prevent an error function connect the wire leads 2 Hot parts correctly referring to the Pictorial Diagram Oven lamp Magnetron High voltage transformer and Oven cavity 26 MMDV30S MMDH30S MICROWAVE DRAWER DISASSEMBLY WARNING Follow all safety precautions as stated at the beginning of this Service Manual before proceeding 1 Before removing Microwave Drawer take measures to protect the Drawer louver by either removing the louver or by letting the louver over hang off flat protected surface Fig 1 Fig 1 2 Open the Drawer to access the 4 mounting screws holding the Louver unit on to the wall or cabinet opening Fig 1 3 Close Drawer and carefully pull t
39. l Unit 39 a MMDV30S MMDH30S cdacor distinctive appliances COPYRIGHT 2006 BY DACOR INC ALL RIGHTS RESERVED No part of this publication may be reproduced 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
40. llowing sequence 1 When the drawer opens from the closed position the secondary interlock relay RY2 and secondary interlock switch open their contacts And contacts of the relay RY1 remains closed Then the monitor switch contacts close 2 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 secondary 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 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 Power 7 P 70 24 sec 8 sec Power 6 P 60 22 sec 10 sec 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
41. ming signal is sent to IC 2 Signal to reset LSI Signal is output to reset IC 2 Turminal not used Common data signal Connected to LCD signal C5 MMDV30S MMDH30S Description Common data signal Connected to LCD signal C4 Connected VC 5V P27 P25 Turminal not used SEG20 Segment data signal Connected to LCD segment S24 Signal coming from touch key When any one of J 4 line keys on key matrix is touched a corresponding signal from P10 P17 will be input into P23 When no key is touched the signal is held at L level Signal similar to P23 When any one of J 3 line keys on key matrix is touched a corresponding signal will be input into P22 Signal similar to P23 When any one of J 2 line keys on key matrix is touched a corresponding signal will be input into P21 Signal similar to P23 When one of J 1 line keys on key matrix is touched a corresponding signal will be input into P20 Key strobe signal Signal applied to touch key section A pulse signal is input to P20 P23 terminal while one of J 12 line key on matrix is touched Key strobe signal Signal applied to touch key section A pulse signal is input to P20 P23 terminal while one of J 11 line key on matrix is touched Key strobe signal Signal applied to touch key section A pulse signal is input to P20 P23 terminal while one of J 10 line key on matrix is touched
42. n 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 Reconnect all leads removed from components during testing Reassemble the unit Reconnect the power supply cord Run the oven and check all functions 1 MONITOR Screw Driver Ohmmeter BRN BLK SECONDARY INTERLOCK SWITCH MMDV30S MMDH30S PROCEDURE LETTER L TEST PROCEDURES COMPONENT TEST BLOWN MONITOR FUSE TEST Disconnect the power supply cord 1 2 Open the drawer and block it open 3 4 Ifthe monitor fuse is blown when the drawer is opened check the primary interlock switch secondary To discharge high voltage capacitor wait for 60 seconds 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 SECONDARY INTERLOCK 1 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 BAO18 KIT even if the monitor switch o
43. nistration s Center for Devices and Radiological Health immediately Service personnel should inform DACOR of any certified unit found with emissions in excess of 4mW The owner of the unit should be instructed not to use the unit until the oven has been brought into compliance MMDV30S MMDH30S WARNING TO SERVICE PERSONNEL Range units contain circuitry capable of producing very high voltage and current contact with following parts may result in a severe possibly fatal electrical shock Example High Voltage Capacitor High Voltage Power Transformer Magnetron High Voltage Rectifier Assembly High Voltage Harness Heating Elements etc Read the Service Manual carefully and follow all instructions Before Servicing Disconnect the power supply cord and then remove cabinet Open the drawer and keep it open Discharge high voltage capacitor WARNING RISK OF ELECTRIC SHOCK DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE SERVICING The high voltage capacitor remains charged about 60 seconds after the oven has been switched off Wait for 60 seconds and then short circuit the connection of the high voltage capacitor that is the connecting lead of the high voltage rectifier against the chassis with the use of an insulated screwdriver Whenever troubleshooting is performed the power supply must be disconnected It may in some cases be necessary to connect the power supply after the outer case h
44. 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 sensor cooking 6 After approximately 16 seconds microwave energy is produced If ERROR is displayed or the oven does not turn off replace the AH sensor or check the control unit refer to explanation below If the oven stops after 5 minutes and no ERROR code is displayed then the AH sensor is normal Check other parts except the AH sensor TESTING METHOD FOR AH SENSOR AND OR CONTROL UNIT To determine if the sensor is defective the simplest method is to replace it with a new replacement sensor 1 Disconnect the power supply cord and then disassemble as per MICROWAVE DRAWER DISASSEMBLY page 25 Open the drawer and block it open Discharge high voltage capacitor Remove the AH sensor Install the new AH sensor Reconnect all leads removed from components during testing Re install the covers Reconnect the power supply cord after the covers are installed Reconnect the oven to the power supply and check the sensor cook operation as follows 9 1 Fill approximately 200 milliliters 7 2 0z of tap water in a 1000 milliliter measuring cup mao eS 1 4 14 MMDV30S MMDH30S TEST PROCEDURES PROCEDURE COMPONENT TEST
45. pen filament isolate the magnetron from the high voltage circuit A continuity check across the magnetron filament leads should indicate less than 1 ohm To test for a shorted magnetron connect the ohmmeter leads between the magnetron filament leads and chassis ground This test should indicate an infinite resistance If there is little or no resistance the magnetron is grounded and must be replaced Reconnect all leads removed from components during testing Reassemble the unit Reconnect the power supply cord Run the oven and check all functions MICROWAVE OUTPUT POWER The following test procedure should be carried out with the microwave oven in a fully assembled condition HIGH VOLTAGES ARE PRESENT DURING THE COOK CYCLE SO EXTREME CAUTION SHOULD BE OBSERVED Power output of the magnetron can be measured by performing a water temperature rise test This test should only be used if above tests do not indicate a faulty magnetron and there is no defect in the following components or wiring inverter unit This test will require a 16 ounce 453cc measuring cup and an accurate mercury thermometer or thermocouple type temperature tester For accurate results the following procedure must be followed carefully 1 Fill the measuring cup with 16 oz 453cc of tap water and measure the temperature of the water with a thermometer or thermocouple temperature tester Stir the thermometer or thermocouple through
46. perates normally The monitor fuse and monitor switch assembly is comprised of a 20 ampere fuse and switch Reconnect all leads removed from components during testing Reassemble the unit Reconnect the power supply cord Run the oven and check all functions POWER TRANSFORMER TEST RON Disconnect power supply cord Open the drawer and block it open Discharge high voltage capacitor 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 Reconnect all leads removed from components during testing Reassemble the unit Reconnect the power supply cord 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 MMDV30S MMDH30S TOUCH CONTROL PANEL ASSEMBLY OUTLINE OF TOUCH CONTROL PANEL The touch control section consists of the following units 1 Key unit 2 Control Unit 3 Power unit The principal functions of these units and the signals com municated among them are explained below Key unit The key unit is composed of a matrix signals generated in t
47. power Power 2 P 20 8 sec 24 sec Power 1 P 10 6 sec 26 sec 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 SENSOR COOKING CONDITION Using the SENSOR function food is cooked without figur ing time power level or quantity When the oven senses enough steam from the food it relays the information to its microprocessor which will calculate the remaining cooking time and power level needed for best results When the food is cooked water vapor is developed the sensor senses the vapor and its resistance increase gradually When the resistance reaches the value set according to the menu supplementary cooking is started The time of supplementary cooking is determined by experi ment with each food category and inputted into the LSI An example of how sensor works Potatoes 1 Potatoes at room temperature Vapor is emitted very slowly 2 Heat Potatoes Moisture and humidity is emitted very rapidly You can smell the aroma as it cooks 3 Sensor detects moisture and humidity and calculates cooking time and variable 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 MMDV30S MMDH30S 2 The coil of shu
48. r In other cooking modes 90 80 70 60 70 power 50 40 30 20 10 0 the signal turns to level and L level in repetition according to the power level 50 power 0 power 4 Used for initial balancing of the bridge circuit absolute humidity sensor P57 Common relay driving signal Square Waveform 60 2 To turn on and off the shut off relays RY1 The uau H 5V square waveform voltage is delivered to the relay ee RY1 driving circuit During cooking Turminal not used Turminal not used Turminal not used Turminal not used Signal to sound buzzer A Key touch sound B Completion sound C When the oven stops so that the food can be checked in Automatic cooking mode 5 L GND Input signal which communicates the drawer door close information to LSI Door opened level signal 5V Door closed L level signal OV Signal to synchronize LSI with commercial power source frequency This is the basic timing for all real time processing of LSI 16 7 msec A D converter power source voltage The power source voltage to drive the A D converter in the LSI Reference voltage input terminal A reference voltage applied to the A D converter in the LSI Connected to 5 AH sensor input This
49. rmal cut out terminals should indicate a closed circuit unless the temperature of the thermal cut out reaches approximately 293 F 145 C An open thermal cut out indicates overheating of the oven exchange the oven thermal cut out and check inside of oven cavity and for improper setting of cooking time or operation of control unit Check for restricted air flow through the vent holes of the oven cavity especially the cooling fan and air guide Reconnect all leads removed from components during testing Reassemble the unit Reconnect the power supply cord Run the unit and check all functions CAUTION IF THE THERMAL CUT OUT INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE REPLACE THERMAL CUT OUT 16 MMDV30S TEST PROCEDURES MMDH30S COMPONENT TEST SECONDARY 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 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 J STOP SWITCH TEST STOP
50. s not fully protected by the built in protection circuit In order to protect CMOS LSI When storing and transporting thoroughly wrap them in aluminium foil Also wrap all PW boards containing them in aluminium foil When soldering ground the technician as shown in the figure and use grounded soldering iron and work table approx 1M ohm Servicing of Touch Control Panel We describe the procedures to permit servicing of the touch control panel of the microwave oven and the precautions you must take when doing so To perform the servicing power to the touch control panel is available either from the power line of the oven itself or from an external power source 1 Servicing the touch control panel with power supply of the oven CAUTION THE HIGH VOLTAGE TRANSFORMER OF THE MICROWAVE OVEN IS STILL LIVE DURING SERVICING AND PRESENTS A HAZARD Therefore before checking the performance of the touch control panel 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 6 After that procedure re connect the power supply cord After checking the performance of the touch control panel 1 Disconnect the power supply cord 2 Open the door and block it open
51. s not operate properly c Cooking is not possible 3 Power Unit or Touch Control Transformer a Fan motor stirrer motor oven lamp or electrical parts do not turn on or do not turn off b Digital display on the control unit does not show anything When testing is completed 1 Disconnect the power supply cord and then disassemble as per MICROWAVE DRAWER DISASSEMBLY page 25 2 Open the drawer and block it open 3 Discharge high voltage capacitor MMDV30S MMDH30S TEST PROCEDURES COMPONENT TEST Reconnect all leads removed from components during testing Re install the covers Reconnect the power supply cord after the covers are installed 4 5 6 7 Run the oven and check all functions DB Na Na B KEY UNIT TEST 1 Disconnect the power supply cord and then remove outer case 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 first verify the flat ribbon cable is making good contact verify that the KEY UNIT door sensing switch stop switch operates properly thatis the contacts are closed when the drawer is closed and open when the drawer is open If the door sensing switch stop switch is good disconnect the flat ribbon cable that connects the key unit to the control unit and make sure the drawer sensing switch is closed either close the drawer or short the door sensin
52. s than 0 5mm The vertical position of the latch hook should be adjusted so that the secondary interlock switch is activated with the drawer closed The horizontal position of the latch hook should be adjusted so that the monitor switch and drawer sensing switch are activated with the drawer closed Secure the screws with washers firmly Check all of the switches operation If any switch has not activated fully you will need to adjust the slide rail attached to the Microwave cavity 10 This is done by following the steps to remove the DRAWER SLIDE RAIL REMOVAL on page 28 After you have removed the slide rails loosen the 2 screws holding the slide rail to the Microwave cavity and tilt the front end up and the rear end down then tighten the 29 screws Fig S 1 11 Check and assure that the cap nuts on the Drawer Support Angles are centered when passing through the cavity face plate After adjustment check the following 1 In and out play of door remains less than 0 5mm when in the latched position First check upper position of latch hook pushing and pulling upper portion of drawer toward the oven face Then check lower portion of the latch hook pushing and pulling lower portion of the door toward the oven face Both results play in the door should be less than 0 5mm The secondary interlock switch switch interrupt the circuit before the door can be opened Monitor switch contacts close when door
53. t lt o a gt io 8 2 22 3 28 877848 i wan 5 WoD 8 2558 245 038 25 2 ON O 940 540 aay 0 0 0 0 0 934 a 930 5 HILIMS 201831 02315 3004 MMDV30S TEST PROCEDURES COMPONENT TEST A TOUCH CONTROL PANEL ASSEMBLY TEST The touch control panel consists of circuits including semiconductors such as LSI ICs etc Therefore unlike conventional microwave ovens proper maint nance cannot be performed with only a voltmeter and ohmmeter In this service manual the touch control panel assembly is divided into three units Control Unit and Keyboard Unit and Power Unit and troubleshooting by unit replacement is described according to the symptoms indicated Before testing 1 Disconnect the power supply cord and then disassemble as per MICROWAVE DRAWER DISASSEMBLY page 25 2 Open the drawer 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 1 Keyboard Unit NOTE 1 Check Keyboard unit connection before replacement Reconnect all leads removed from components during testing Re install the covers R
54. t is equivalent to the oven door being closed Connect an external power source to the power input terminal of the touch control panel then it is possible to check and repair the controls of the touch control panel it is also possible to check the sensor related controls of the touch control panel by using the dummy resistor s Servicing Tools Tools required to service the touch control panel assembly 1 Soldering iron 30W It is recommended to use a soldering iron with a grounding terminal 2 Oscilloscope Single beam frequency range DC 10 type or more advanced model 3 Others Hand tools Other Precautions 1 Before turning on the power source of the control unit remove the aluminium foil applied for preventing static electricity Connect the connectors of the key unit to the control unit being sure that the lead wires are not twisted 3 After aluminium foil is removed be careful that abnormal voltage due to static electricity etc is not applied to the input or output terminals 4 Attach connectors electrolytic capacitors etc to making sure that all connections are tight 5 Be sure to use specified components where high precision is required MMDV30S MMDH30S PRECAUTIONS FOR USING LEAD FREE SOLDER 1 Employing lead free solder The Main of this model employs lead free solder This is indicated by the LF symbol printed on the PWB and in the service manual The s
55. t 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 microwave energy is produced and first stage is started The 16 seconds is the cooling time required to remove any vapor from the oven cavity and sensor NOTE During this first stage do not open the drawer or touch STOP CLEAR pad 4 When the sensor detects the vapor emitted from the food the display switches over to the remaining cooking time and the timer counts down to zero At this time the drawer may be opened to stir turn or season food 5 When the timer reaches zero an audible signal sounds The shut off relay and cook relay are de energized and the power transformer oven lamp etc are turned off 6 Opening the drawer or touching the STOP CLEAR pad the time of the day will reappear on the display and the oven will revert to an OFF condition When the timer reaches zero an audible signal sounds aq 35 Pea 4 JAMO losuas aynjosqe asn sjapow 40 76 aq 15 MBIA 4 120 dwej apis UO 116 1005 MND 10
56. tage Harness etc If provided Vent Hood Fan assembly Cooling Fan Motor All the parts marked on parts list are used at voltages more than 250V Removal of the outer wrapper gives access to voltage above 250V All the parts marked A on parts list may cause undue microwave exposure by themselves or when they are damaged loosened or removed dacor distinctive appliances 1440 Bridge Gate Dr Diamond Bar CA 91765 MMDV30S MMDH30S MICROWAVE DRAWER SPECIFICATION ITEM DESCRIPTION Power Requirments 120 Volts 13 6 Amperes 1500 watts 60 Hz Single phase 3 wire grounded Power Output 950 watts IEC TEST PROCEDURE Operating frequency of 2450MHz Cooking Cavity Dimensions Width 17 11 32 Height 5 7 8 1 0 Cubic Feet Depth 17 1 8 Case Dimensions Width 30 Height 15 11 16 Depth 24 1 8 Control Complement Touch Control System Clock 1 00 12 59 Timer 0 99 min 99 seconds Microwave Power for Variable Cooking Repetition Rate Full power throughout the cooking time 90 of Full Power 80 of Full Power 70 of Full Power 60 of Full Power 50 of Full Power 40 of Full Power 30 of Full Power 20 of Full Power 10 of Full Power No power throughout the cooking time START EASY MINUTE pad Defrost pad Number selection pad Micro warm pad Power Level pad Timer Clock pad Stop Clear pad Sensor Reheat Sensor Popcorn Sensor Cook Open pad Close pad Setup Custom Help
57. uffix letter indicates the alloy type of the solder Sn Ag Cu Indicates lead free solder of tin silver and copper 2 Using lead free wire solder When repairing a PWB with the LF symbol only lead free solder should be used Using normal tin lead alloy solder may result in cold soldered joints and damage to printed patterns As the melting point of lead free solder is approximately 40 C higher than tin lead alloy solder it is recommend that a dedicated bit is used and that the iron temperature is adjusted accordingly 3 Soldering As the melting point of lead free solder Sn Ag Cu is higher and has poorer wettability flow to prevent damage to the land of the PWB extreme care should be taken not to leave the bit in contact with the PWB for an extended period of time Remove the bit as soon as a good flow is achieved The high content of tin in lead free solder will cause premature corrosion of the bit To reduce wear on the bit reduce the temperature or turn off the iron when it is not required Leaving different types of solder on the bit will cause contamination of the different alloys which will alter their characteristics making good soldering more difficult It will be necessary to clean and replace bits more often when 25 MMDV30S MMDH30S COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE WARNING AGAINST HIGH VOLTAGE Microwave ovens contain circuitry capable of producing very high voltage and
58. uit RY1 RY2 RY3 and RY4 Relay Test These relays are operated by D C voltage Check voltage at the relay coil with a D C voltmeter during the microwave cooking operation DC voltage indicated Defective relay DC voltage not indicated Check diode which is connected to the relay coil If diode is good control unit is defective NO RELAY SYMBOL OPERATIONAL VOLTAGE RY1 Approx 26V D C Oven lamp Common RY2 Approx 25V D C X D RY4 Approx 26V D C RY5 Approx 26V D C 8 Disconnect the power supply cord and then remove outer case 9 Open the door and block it open 10 Discharge high voltage capacitor MMDV30S MMDH30S TEST PROCEDURES PROCEDERE COMPONENT TEST LETTER ammm 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 0 516 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 STAGE LEVEL TIME LEVEL TIME LEVEL TIME 0 5lb 60
59. w each switch is free Re install 1 Re install each switch in its place The secondary interlock switch is in the lower position and the monitor switch is Latch Hook Left Follow the Microwave Drawer disassembly as previously stated Open the drawer and keep it open To discharge the high voltage capacitor wait for 60 in the top position located on the left side of the unit The door sensing switch by itself on the right side of the unit Re connect wire leads to each switch Refer to pictorial diagram Secure the latch hooks with mounting screws to oven flange Make sure that the monitor switch is operating properly and check continuity of the monitor circuit Refer to chapter Test Procedure and Adjustment procedure Latch Hook Right STOP SWITCH SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH ADJUSTMENT Follow the Microwave Drawer disassembly as previously stated Open the drawer and keep it open To discharge the high voltage capacitor wait for 60 seconds If the door sensing switch secondary interlock switch and monitor switch do not operate properly due to a misadjustment the following adjustment should be made Loosen the screw holding latch hook to the oven cavity flange 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 les
60. w the oven to be operated with the door open b Make the following safety checks on all ovens to be serviced before activating the magnetron or other microwave source and make repairs as necessary 1 interlock operation 2 proper door closing 3 seal and sealing surfaces arcing wear and other damage 4 damage to or loosening of hinges and latches 5 evidence of dropping or abuse c Before turning on microwave power for any service test or inspection within the microwave generating compart ments check the magnetron wave guide or transmission line and cavity for proper alignment integrity and connections d Any defective or misadjusted components in the interlock monitor door seal and microwave generation 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 Microwave Measure ment Procedure outlined in this service manual If microwave emissions level is in excess of the specified limit contact DACOR immediately 1 800 793 0093 If the unit operates with the door open service person should 1 tell the user not to operate the oven and 2 contact DACOR and Food and Drug Admi

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