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Viking DMOC205SS User's Manual

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2. CONV MAGNETRON OVEN THERMAL THERMAL THERMAL _NOISE FILTER CUT OUT CUT OUT CUT OUT E 5 N M 9 5 COM id 3 RY1 S e gt 8 QR Qs ui S x x 5 Q j e POWER P 3 5 IE TRANSFORMER N 2 Az sell a 251 E 95 5 e 8 z NS RY2 5 9 S E SECONDARY z h __ INTERLOCK A 3 Plo RERAY 6 z z z RY2 lt 2 x 55 t E i 6 5 N O 2 Z E 6 F 3 F 2 F 1 oe G x 7 ah LJ A I 25 EV DOOR THER DAMPER SENSING gt THIRD DOOR MISTOR SWITCH THIRD O SWITCH 0 O bd hd JIT 777 Figure 1 Oven Schematic OFF Condition SCHEMATIC NOTE CONDITION OF OVEN 1 DOOR CLOSED 2 COOKING TIME PROGRAMMED 3 START PAD TOUCHED CONV MAGNETRON OVEN THERMAL THERMAL THERMAL _NOISE FILTER CUT OUT CUT OUT CUT OUT I 8 gt io 8 9 lt 5
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6. CAPACITOR 5 lt 5 0 94u o a Q 2 5 gle 1 2 5 6 F3 F2 FA b j e 2 PEUR 117V T 60Hz m SENSI THER 1 5 5 SENSING THIRD DOOR SWITCH MISTOR 77 SENS R 2 Figure 3 Oven Schematic Automatic Mix Cooking Condition SCHEMATIC NOTE CONDITION OF OVEN 1 DOOR CLOSED 2 CONVECTION PAD TOUCHED 3 DESIRED TEMP TOUCHED 4 COOKING TIMEPROGRAMMED 5 START PAD TOUCHED CONV MAGNETRON OVEN THERMAL THERMAL THERMAL CUT OUT CUT OUT CUT OUT 8 gt E io 2 l i c e a a 3 c ats 8 ui 218 5 E 2 ES x x a g E o e E POWER P 5 5 lt TRANSFORMER q N 2 15 COM e O s 3 d E GX 5 8 z ay 5 x 5 g e n riz SECONDARY RY2 S z P S so o INTERLOCK 2 5 75 RERAY N O 5 2 RY2 4 CAPACITOR 5 u z n E 0 94 iS lt 94 2 N O 15 5 1 2 4 E 5 E 6 F 3 F 2 F 1 eue x V ERE u ui 117V E 60Hz MWD m DOCE THER SENSING AH SEN
7. H level GND Thermistor OPEN timing L level 5V Temperature measuring timing Convection cooking Signal to synchronize LSI with commercial power source frequency ON B 60Hz This is the basic timing for all real time processing of LSI 16 7 msec Connected to GND Auto clear terminal Signal is input to reset the LSI to the initial state when power is applied Temporarily set to L level the moment power is applied at this time the LSI is reset Thereafter set at H level Terminal not used 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 Signal coming from touch key When any one of G 1 line keys on key matrix is touched a corresponding signal from P10 P17 will be input into P27 When no key is touched the signal is held at L level Signal similar to P27 When any one of G 2 line key on key matrix is touched a corresponding signal will be input into P26 Signal similar to P27 When any one of G 3 line key on key matrix is touched a corresponding signal will be input into P25 Signal similar to P27 When any one of G 4 line key on key matrix
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9. Thermistor _ J Ventilation element openings View of sensor case removed Cross section view 2 Operational Principle of Absolute 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 Each thermistor is supplied with a current to keep it heated at about 150 C 302 F the resultant heat is dissipated in the air and if the two thermistors are placed in different 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 very minute it is amplified by the operational amplifier Absolute humidity vs output voltage characterist Operational R1 amplifier Output voltage Output voltage S Thermistor open vessel C Thermistor closed vessel Absolute humidity g m2 3 Detector Circuitof Absolute 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 27 than the detector circuit starts to function and
10. i 8 CM i 51 2 5 e x z D o 2 E lt 5 5 lt TRANSFORMER 219 gt 5 z E lt o a i DM z 69 5 S o x z 5 2 SECONDARY s z 55 9 L INTERLOCK 5 u 3 Slo CONTROL UNIT 6 z z lt o CAPACITOR 2 x E 0 94 lt 2 A 2 o N O lt io Z 5 1 2 E 3 E4 E 5 F 6 F 3 F2 F4 9 L x 16 e w 60Hz THER DAMPER 5 SENSING SD DOOR SWITCH MISTOR SWITCH eo gt Figure O 2 Oven Schematic Microwave Cooking Condition 11 DMOC205SS VMOC205SS SCHEMATIC NOTE CONDITION OF OVEN 1 DOOR CLOSED 2 MIX COOKING PAD TOUCHED 3 COOKING TIME PROGRAMMED 4 START PAD TOUCHED 5 RY2 AND RY3 WILL ALTERNATELY CLOSE DURING COOK CYCLE OVEN 22 CUT OUT CUT OUT CUT OUT x 2 lt 5 a e amp 8 x 218 a D POWER 18 5 lt TRANSFORMER 2 gt 74 0 0033 125 TURNTABLE MOTOR CONVECTION MOTOR 5 z E a x x SECONDARY z e INTERLOCK 5 N 3 CONTROL UNIT 22
11. 1 2 OVEN AND CABINET PARTS BASE PLATE 4 23 3 iJ a TO OVEN 42 DMOC205SS VMOC205SS 1 2 CONTROL PANEL PARTS C O 1 2 3 4 5 6 DMOC205SS VMOC205SS 1 2 3 4 5 6 PACKING AND AGGESSORIES A TOP PAD ASSEMBLY DOOR PROTECTION SHEET 4 3 TURNTABLE TRAY PLASTIC BAG B 6 9 OPERATION D MANUAL 6 14 S S CLEANING INSTRUCTIONS 6 15 PA MICROWAVE OVEN N Z lt 4 2 TURNTABLE SUPPORT ER _ S SE lt Img 5 BOTTOM PAD ASSEMBLY S N TRAY PACKING FOAM D PACKING CASE Not replaceable items E F G H 44 DMOC205SS VMOC205SS NOTES 45 DMOC205SS VMOC205SS VIKING COPYRIGHT 2004 BY VIKING ALL RIGHTS RESERVED No part of this publication may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording or otherwise without prior written permission of the publisher VIKING RANGE CORPORATION 111 Front St Greenwood MS 38930 Tel 888 845 4641
12. 15 or more 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 A short power supply cord is provided to reduce risks of becoming entangled in or tripping over a longer cord Where a two pronged wall receptacle is encountered it is the personal responsibility and obligation of the customer to contact a qualified electrician and have it replaced with a properly grounded three pronged wall receptacle or have a grounding adapter properly grounded and polarized If an extension cord must be used it should be a 3 wire 15 amp or more cord Do not drape over a countertop ortable where it can be pulled on by children or tripped over accidentally DMOC205SS VMOC205SS 3 Pronged Plug Grounded Receptacle Box Grounding Pin 3 Pronged Receptacle CAUTION DO NOT UNDER CIRCUMSTANCES CUT OR REMOVE THE ROUND GROUNDING PRONG FROM THIS PLUG OVEN DIAGRAM 1 Ventilation openings Rear side 7 Wave guide cover 2 Oven door with see through window 8 Door open button 3 Oven lamp 9 Auto Touch control panel 4 Turntable support 10 Lighted digital display 5 Removable turntable 11 Convection air openings The turntable will rotate clockwise or 12 Removable low rack Broiling trivet counterclockwise 13 Removable low rack Baking rac
13. Low rack Broiling trivet High rack Baking rack Thermistor harness Main wire harness High voltage wire B DMOC205SS VMOC205SS Grounding wire Cooling fan motor Monitor caution label NHW caution label Operation manual DMOC205SS Operation manual VMOC205SS Purse lock LL User caution BIK label GND caution label S S cleaning instructions Cook book UL screw label SCREWS NUTS AND WASHERS Screw 4mm x 10mm Screw 4mm x 12mm Screw 4mm x 8mm Screw 4mm x 8mm Special screw Washer 6mm x 0 7 mm Washer Special screw Screw 3mm x 14mm Screw 4mm x 25mm p PNOARPRPPPPPP EY M BHBppBNHHHHHBHHHHHHHB BHNHHHBHBHHIHAA N P O F F DMOC205SS VMOC205SS ETS PART NO DESCRIPTION XBTWW40P06000 Screw 4mm x 6mm XCTSD40P08000 Screw 4mm x 8mm LX NZ0029YBEO Special nut XBPSD40PO6KSO Screw 4mm x 6mm LX WZAO22WREO Washer LX BZ0531FCZZ Screw 4mm x 8mm XCPSD30P06000 Screw 3mm x 6mm LX CZA038WREO Special screw XFPSDAOPOS8KO00 Screw 4mm x 8mm XBPSD40P06000 Screw 4mm 6mm XCBWW30P06000 Screw 3mm 6mm XFPSD40P08000 Screw 4mm 8mm XFPSD60P1A4JSO Screw 6mm 14mm XOTSD40P12000 Screw 4mm 12mm XFPSD30P08000 Screw 3mm 8mm XNESD40 32000 Nut 4mm x 2mm XNEUW40 32000 Nut 4mm x 2mm XWSUW40 10000 Washer 4mm x 1 mm X CZAO70WREO Screw UL W QN N H HN N HN OO S F OFF O ON HN HA 41 DMOC205SS VMOC205SS m
14. 2 Remove screws from rear and along the side edge of CAUTION DISCONNECTOVENFROM POWER SUPPLY case BEFORE REMOVING OUTER CASE 3 Slide the entire case back out about 1 inch 3 cm to free POWER TRANSFORMER REMOVAL 1 Disconnect oven from power supply and remove outer 3 Make sure the transformer is mounted correctly to the case corners underneath those tabs 2 Discharge high voltage capacitor 4 Afterre installingthe transformer secure the transformer 3 Disconnect filament leads of transformer from the with two screws to the base cabinet one is with outer magnetron and capacitor toothwasherandthe otheris without outer tooth washer 4 Disconnect high voltage lead of capacitor from the 5 Re connect the wire leads primary and high voltage transformer and high voltage lead to the transformer and filament 5 Disconnect wire leads from the transformer leads of transformer to the magnetron and capacitor 6 Remove two 2 screws holding the transformer to the referring to the Pictorial Diagram base cabinet 6 Re install the outer case and check that the oven is Re install operating properly 1 Restthetransformer on the base cabinet with its primary NOTE HOT ORANGE WIRE MUST BE CONNECTED terminals toward rear cabinet f TO THE POWER TRANSFORMER TERMINAL 2 Insert the two edges of the transformer into two metal NEAREST TO THE TRANSFORMER MOUNTING tabs of the base cabinet SCREW MAGNETRON REMOVAL 1 Disconnect oven from power supply
15. High Voltage Capacitor Power Transformer Magnetron High Voltage Rectifier Assembly High Voltage Harness 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 wrap 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 VIKING RANGE CORPORATION 111 Front St Greenwood MS 38930 Tel 888 845 4641 DMOC205SS VMOC205SS PRODUCT DESCRIPTION GENERAL INFORMATION OPERATION TROUBLESHOOTING GUIDE AND TESTPROCEDURE TOUCH CONTROL PANEL COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE WIRING DIAGRAM PARTS LIST DMOC205SS VMOC205SS SPECIFICATION ITEM DESCRIPTION Power Requirements 120 Volts 13 0 Amperes Microwave 13 0 Amperes Convection 60 Hertz Single phase 3 wire grounded Power Output 900 watts IEC 705 Test Procedure Operating frequency of 2450MHz Convection Power Output 1450 Watts Case Dimensions Width 24 5 8 Height 14 7 8 Depth 19 1 8 Cooking Cavity Dimensions 1 5 Cubic Feet Width 16 1 8 Height 9 5 8 Depth 16 1 8 Control Complement Touch Control System Timer 0 99 min 99 seconds Microwave Power for Variable Cooking Repetition Rate Full power throughout the cooking time approx 90 of Full Power approx 80 of Full P
16. INSIDE Choke cover Upper Lower FRONT Figure C 6 Door Disassembly DMOC205SS VMOC205SS MICROWAVE MEASUREMENT PROCEDURE After adjustment of the door interlock and monitor switches are completed individual or collectively interlock switch test and microwave leakage test must be performed with survey instrument and test results must be confirmed to meet the requirement of the performance standard for microwave ovens as undermentioned Requirement Every microwave oven shall function in such a manner that when the oven is fully assembled and operating with it s service controls and user controls adjusted to yield the maximum output the leakage radiation at all points at least 5 cm from the external surface of the oven does not exceed 1 1 0mW cm with the test load 275x15ml of water at an initial temperature of 20 5 C 2 5 0mW cm when the outer enclosure is removed with a test load of 275x15ml water at an initial temperature of 20 5 C 3 5 0mW cm without a test load Preparation For Testing Before beginning the actual measurement of leakage proceed as follows 1 Makesurethatthe actualinstrumentis operating normally as specified in its instruction booklet Note Surveyinstruments that comply with the requirement for instrumentation as prescribed by CSA and NHW performance standard for microwave ovens must be used for testing Recommended instruments are NARDA 8100 N
17. Note DMOC205SS VMOC205SS The sensor senses the vapor and its resistance increases 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 1 Potatoes at temperature Vapor is emitted very slowly room 2 Heat potatoes Moisture and humidity is emitted rapidly You can smellthe aroma as it cooks 3 Sensor detects moisture and humidity and calculates cooking time and variable power Cooking Sequence 1 Touch SENSOR COOK pad NOTE The oven should not be operated on SENSOR COOK immediately after plugging in the unit Wait two minutes before cooking on SENSOR COOK 2 Select desired Sensor setting 3 Touch START pad The coil of shut off relay RY1 RY6 is energized the oven lamp and cooling fan motor are turned on but the power transformer is not turned on 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 door or touch STOP CLEAR pad 5 When the sensor detects the vapor emitted from the food the display switches over to the remaining cooki
18. connected to the relays are turned on as follows For details refer to Figure O 2 RELAY CONNECTED COMPONENTS RY 1 Oven lamp Turntable motor RY 2 Power transformer RY 3 Heating element RY 4 Damper motor RY 5 Convevtion motor RY 6 Fan motor 2 117 volts A C is supplied to the primary winding of the power transformer and is converted to about 3 volts A C output on the filament winding and approximately 2360 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 door is opened during a cook cycle third door switch monitor switch door sensing switch the secondary interlock relay and the primary interlock switch are activated with the following results The circuits to the turntable 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 Themonitorswitchis electrically monitoring the o
19. ofthe possible causes of trouble will require that a specific test be performed These tests are given a procedure letter which will be found in the Test Procedure section IMPORTANT If the oven becomes inoperative because of a blown monitor fuse check the monitor switch relay RY 1 door sensing switch and primary interlock switch before replacing the monitor fuse If monitor fuse is replaced the mintor switch must also be replaced at the same time Use part FFS BAO12WRKO as assembly o 22 oo N 55 gt Jaye 02 Jio suum Josues HV JO pue JOU s op 10sues HY 10SU8S eu ueAQ uMop sinus ueuj spuooes G pue p suni 9jo o uun y 10 suni 92 59 26 gt 2 2 r gt lt z a 2 o 9 z 2 2 Q o I o E a jeseJd uey 10 SI uano eu yeay seop 1nq syys ANOD peuonoi s ped LHYLS 81949 009 jou seop 1nq s1uBi ANOD Auedoud ejejedo jou seop 1S0H1q uonounJj amod H IH 1deoxe ejejedo jou seop Hulyooo ejqeuea zo uonounJ
20. 4 Re install outer case and check for microwave leakage around door with an approved microwave survey meter Refer to Microwave Measurement Procedure Note The door on 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 airtight moisture condensation tight or light tight Therefore occasional appearance of moisture light or sensing of gentle warm air movement around oven dooris not abnormal and do not of themselves indicate a leakage of microwave energy from oven cavity If such were the case your oven could not be equipped with a vent the very purpose of which is to exhaust the vapor laden air from the oven cavity Bp RE nota OZ DOOR ASSEMBLY A Figure C 5 Door Replacement and adjustment DOOR DISASSEMBLY Remove door assembly refer to Door Replacement Replacement of door components are as follows 1 Place door assembly on a soft cloth with latches facing up Note Asthe engaging part of choke cover and door panel are provided at several places do not force any particular part 2 Insert an putty knife thickness of about 0 5mm into the gap between the choke cover and corner portion of door panel as shown Figure C 6 to free engaging parts 3 Lift up choke cover 4 Now choke cover is free from door panel 34 2 UP Door Bent Panel
21. A HAZARD Therefore when checking the performance of the touch control panel put the outer cabinet on the oven to avoid touching the high voltage transformer or unplug the primary terminal connector of the high voltage transformer to turn it off the end of such connector must be insulated with an insulating tape After servicing be sure to replace the leads to their original locations 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 28 while keeping it connected to the oven 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 therefore 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 brings about 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 X
22. D from 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 brings about an operational state that is equivalent to the oven door being closed Connect an external power source to the power input terminal of the touch control panel then itis 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 Soldering iron 30W It is recommended to use a soldering iron with a grounding terminal Oscilloscope Single beam frequency range DC 10MHz type or more advanced model Others Hand tools Other Precautions Before turning on the power source of the control unit remove the aluminum foil applied for preventing static electricity Connect the connector of the key unit to the control unit being sure that the lead wires are not twisted After aluminum foil is removed be careful that abnormal voltage due to static electricity etc is not applied to the input or output terminals Attach connectors electrolytic capacitors etc to PWB making sure that all connections are tight Be sure to use specified components where high precision is required DMOC205SS VMOC205SS COMPONENT
23. Discharge the high voltage capacitor 3 Remove the AH sensor 4 Install the new AH sensor 5 Re install the outer case 6 Reconnect the oven to the power supply and check the sensor cook operation proceed as follows 6 1 Fill approximately 200 milliliters 7 2 oz of tap water in a 1000 milliliter measuring cup 6 2 Place the container on the center of tray in the oven cavity 6 3 Close the door 6 4 Touch SENSOR COOK pad and number 1 pad 6 5 Touch Start pad The control panel is in automatic Sensor operation 6 6 The display will start to count down the remaining cooking time and the oven will turn off automatically after the water is boiling bubbling If new sensor dose not operate properly the problem is with the control unit CHECKING CONTROL UNIT isconnect oven from power supply and remove outer case ischarge the high voltage capacitor isconnect the wire leads from the cook relay isconnect the sensor connector that is mounted to lower portion of control panel Then connect the dummy resistor circuit see fig to the sensor connector of control panel Reconnect the oven to the power supply and check the sensor cook operation proceed as follows 6 1 Touch SENSOR COOK pad and number 1 pad 6 2 Touch Start pad The control panel is in the sensor cooking operation 6 3 After approximately 20 seconds push plunger of select switch for more than 3 seconds This condition is same as judgement by AH sensor 6 4 A
24. all leads removed from components during testing 2 Reinstall the outer case cabinet 3 Reconnectthe power supply cord after the outer case is installed 4 Run the oven and check all functions Microwave ovens should not be run empty To test for the presence of microwave energy within a cavity place a cup of cold water on the oven turntable close the door 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 and the oven is fully assembled the microwave power output should be checked and a microwave leakage test should be carried out DMOC205SS VMOC205SS MICROWAVE MEASUREMENT PROCEDURE CANADA After adjustment of the door switches are completed individually or collectively switch test and microwave leakage test must be performed with survey instrument and test result must be confirmed to meetthe requirement of the performance standard for microwave ovens as undermentioned A Requirements Every microwave oven shall function in such a manner that when the oven is fully assembled and operating with its service controls and user controls adjusted to yield the maximum output the leakage radiation at all points at least 5 cm from the external surface
25. ance which is approximately 1750 x 10 If A a 5 any abnormal condition is detected replace 9 E lt a the defective parts m I gt e U AH SENSOR TEST Checking the initial sensor cooking condition 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 a conventional surface unit Refer to the INSTALLATION Instructions 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 b Be surethe 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 vapour given of by the spray and turn off before food is properly cooked 8 After 30 minutes if the sensor has not detected the vapour of the food ERROR will appear and the oven will shut off Water load cooking test Make sure the oven has bee
26. and remove outer 4 Remove the magnetron from the unit with care so the case magnetron tube should not hit by any metal object 2 Discharge the high voltage capacitor Disconnectfilament around the tube lead of transformer from magnetron Disconnect high CAUTION WHEN REPLACING THE MAGNETRON BE vonage WIS ead tom magnetron SURE THE R F GASKET IS IN PLACE AND 3 Carefully remove four 4 mounting screws hold the D magnetron to waveguide when removing the screws holding the magnetron to prevent it from falling 29 THEMAGNETRONMOUNTING SCREWS ARE TIGHTENED SECURELY DMOC205SS VMOC205SS HIGH VOLTAGE RECTIFIER ASSEMBLY REMOVAL Disconnect oven from power supply and remove outer case Discharge the high voltage capacitor Remove one 1 screw holding the rectifier assembly to the capacitor holder Disconnect the rectifier assembly from the capacitor and magnetron CAUTION WHEN REPLACING THE SILICON RECTIFIER ASSEMBLY THE GROUND SIDE TERMINAL MUST BE SECURED FIRMLY WITH A GROUNDING SCREW HIGH VOLTAGE CAPACITOR REMOVAL Disconnect oven from power supply and remove outer case Discharge the high voltage capacitor Disconnect the high voltage wire leads and rectifier assembly from high voltage capacitor and magnetron Disconnectfilamentlead oftransformerfrom high voltage capacitor POSITIVE LOCK CONNECTOR NO CASE TYPE REMOVAL Push the lever of positive lock connector Pul
27. 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 mustbe disconnected lt may in some cases be necessary to connect the power supply 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 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 Don t Touch Danger High Voltage outer case 2 Open the door and block it open 3 Discharge high voltage capacitor 4 Reconnect the leads to the primary of the power transformer 5 Reinstall the outer case cabinet 6 Reconnectthe power supply cord after the outer case is installed 7 Run the oven and check all functions After repairing 1 Reconnect
28. in the control unit and operates shut off relay RY4 1 2 Contacts of shut off relay RY4 close the damper motor is energized opening the damper door 1 3 When the damper is moved to the open position by the damper cam the damper switch is closed ON position 1 4 The signal from damper switch is re sensed in the control unit and shut off relay RY4 is turned off 1 5 The 120 volts A C to the damper motor is removed and the motor turns off 2 When oven is microwave cooking Damper is in the open position 3 When oven is convection cooking 3 1 Damper motor is energized by touching the convection temperature and START pads 3 2 When damper is in the closed position damper Switch is OFF its signal is sensed by the control unit and shut off relay RY4 is de energized 3 3 The damper is held in the closed position during the convection cooking operation 3 4 At the end of the convection cooking shut off relay RY4 is energized and the damper is returned to the open position NOTE If the damper door is not in the proper position closed during convection or open during microwave the control unit will stop oven operation after 1 minute Figure D 2 Damper Mechanism DAMPER SHAFT DAMPER DUCT DAMPER DAMPER CAM DAMPER SWITCH DAMPER MOTOR TROUBLESHOOTING GUIDE When troubleshooting the microwave oven it is helpful to follow the Sequence of Operation in performing the checks Many
29. is touched a corresponding signal will be input into P24 25 DMOC205SS VMOC205SS PinNo Signal 10 Description O Segment data signals The relation between signals and indicators are as follows Signal Segment Signal Segment Signal Segment Signal Segment P22 P20 Segment data signal Signal similar to P23 P17 Segment data signal Signal similar to P23 Key strobe signal Signal applied to touch key section A pulse signal is input to P24 P27 terminal while one of G 12 line keys on key matrix is touched Segment data signal Signal similar to P23 Key strobe signal Signal applied to touch key section A pulse signal is input to P24 P27 terminal while one of G 11 line keys on key matrix is touched Segment data signal Signal similar to P23 Key strobe signal Signal applied to touch key section A pulse signal is input to P24 P27 terminal while one of G 10 line keys on key matrix is touched Segment data signal Signal similar to P23 Key strobe signal Signal applied to touch key section A pulse signal is input to P24 P27 terminal while one of G 9 line keys on key matrix is touched Segment data signal Signal similar to P23 Key strobe signal Signal applied to touch key section A pulse signal is input to P24 P27 terminal while one of G 8 line keys on key matrix is touched Segment data signal Signal similar to P23 Key
30. or blocked air intake etc Under normal operation the thermal cut out remains closed However when abnormally high temperatures are reached within the heater unit the thermal cut out will open at 302 F 150 C causing the oven to shut down When the thermal cut out has cooled the thermal cut out closes at 266 F 130 C HEATING ELEMENT The heating element is located at the left side of the oven cavity It is intended to heat air driven by the convection fan The heated air is kept in the oven and force circulated and reheated by the heating element CONVECTION COOKING SYSTEM This oven is designed with a hot air heating system where food is not directly heated by the heating element but is heated by forced circulation of the hot air produced by the heating element The air heated by the heating element is circulated through the convection passage provided on the outer casing of the DMOC205SS VMOC205SS oven cavity by means of the convection fan which is driven by the convection motor It then enters the inside of the oven through the vent holes provided on the left side of the oven Next the hot air heats the food on the turntable and leaves the oven cavity through the vent in the center of the oven cavity left side wall Without leaving the oven this hot air is reheated by the heating element passes through the convection passage and enters the inside of the oven cavity again in a continuing cycle In this way
31. receptacle 2 Disconnect the wire leads of motor and connect the meter leads to the wire leads of main wire harness 3 Re connect the power cord into the wall receptacle If 117 volts A C is indicated atthe wire leads replace the motor and if 117 volts A C is not indicated check the wire harness and control unit DAMPER SWITCH TEST Disconnectthe wire leads from the switch terminals and connect ohmmeter leads to the common COM and normally open N O terminals of the switch 1 When switch actuator is pushed by the damper motor cam the meter should be indicated a closed circuit 2 When power cord is plugged into the wall receptacle the damper motor operates and damper cam will start to rotate When the switch actuator is released the meter should be indicated an open circuit If improper operation is indicated replace the damper switch CHECKING TEMPERATURE IN THE CONVECTION MODE It is difficult to measure the exact temperature the convection oven An accurate thermocouple type 18 PROCEDURE LETTER TESTPROCEDURES COMPONENT TEST DMOC205SS VMOC205SS temperature tester must be used A low priced bi metal type thermometer is not reliable or accurate The temperature should be checked with outer case cabinet installed approx 5 minutes after preheat temperature is reached audible signal sounds four times The temperature experienced may be approx 30 F more orless than indicated on the display however in m
32. temperature rise test indicates a power output well beyond the normal limits The test is only accurate if the power supply line voltage is 117 volts and the oven cavity is clean POWER TRANSFORMER TEST DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPONENTS OR WIRING 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 84 4 ohms the resistance of the filament coil should be less than 1 ohm HIGH VOLTAGES ARE PRESENT AT THE HIGH VOLTAGE TERMINAL SO DO NOT ATTEMPT TO MEASURE THE FILAMENT AND HIGH VOLTAGE HIGH VOLTAGE RECTIFIER TEST DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPONENTS OR WIRING Isolate the rectifier from the circuit Using the highest ohm scale of the meter read the resistance across the terminals and observe reverse the leads to the rectifier terminals and observe meter reading If a short is indicated in both directions or if an infinite resistance is read in both directions the rectifier is probably defective and should be replaced HIGH VOLTAGE CAPACITOR TEST DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPONENTS OR WIRING 16 DMOC205SS VMOC205SS TESTPROCEDURES PROCED
33. 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 R50 1 Changing the resistance values results in that there is the same potential at both F 3 terminal of the absolute humidity sensor and AN7 terminal of the LSI The voltage of AN6 terminal will indicate about 2 5V This initial balancing is set up about 16 seconds after the unit is put in the Sensor Cooking mode Asthe sensorcooking 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 AN6 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 starts to detect the initial voltage at AN6 terminal 16 seconds after the unit has been put in the Sensor Cooking mode if it is not possible to balance of the bridge circuit due to disconnection of the absolute humidity sensor ERROR will appear on the display and the cooking is stopped 1 Absolute humidity sensor circuit _IC2 IZA495DR C Thermistor in closed vesssl 1 S Thermistor in open vessel VA
34. use the unituntil the oven has been brought into compliance DANGER CAUTION HIGH VOLTAGE Do not energize a microwave oven with the outer case cabinet removed because a microwave oven generates High Voltage in the circuit If you intend to operate the oven employing the high frequency switching power converter circuit you should take special precautions to avoid an electrical shock hazard The high voltage transformer high voltage capacitor and high voltage diode have energized high voltage potential approx 8 KV The aluminium heat sink is connected to the switching power transistor Collector pole and has an energized high voltage potential approx 650V peak DO NOT ACCESS THE HIGH VOLTAGE TRANSFORMER HIGH VOLTAGE CAPACITOR HIGH VOLTAGE DIODE AND HEAT SINK WHEN THE POWER SUPPLY IS CONNECTED TO AN ELECTRICAL OUTLET DMOC205SS VMOC205SS Notes DMOC205SS VMOC205SS WARNING TO SERVICE PERSONNEL Microwave ovens contain circuitry capable of pro ducing 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 etc Read the Service Manual carefully and follow all instructions Before Servicing 1 Disconnect the power supply then remove outer case 2 Open the door and block it open 3 Discharge
35. 0 sec approx 6096 power Power 5 P 50 18 sec 14 sec approx 5096 power Power 4 P 40 16 sec 16 sec approx 4096 power Power 3 P 30 12 sec 20 sec approx 3096 power Power 2 P 20 8 sec 24 sec approx 2096 power Power 1 P 10 6 sec 26 sec approx 1096 power Power O P 0 0 sec 32 sec 096 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 CONVECTION COOKING CONDITION PREHEATING CONDITION Program desired convection temperature by touching the CONVECTION pad and the Temperature pad When the START pad is touched the following operations occur 1 The coil of shut off relays RY1 RY3 RY5 and RY6 are energized the oven lamp cooling fan motor turntable motor and convection motor are turned on 2 The coil of relay RY4 is energized by the control unit The damper is moved to the closed position opening the damper switch contacts The opening of the damper Switch contacts sends a signal to the LSI on the control unit de energizing the relay RY4 and opening the circuit to the damper motor 3 Thecoil of heater relay is energized by the control unit and the main supply voltage is applied to the heating element 4 Whentheoventemperature reaches the selected preheat temperature the following operations occur 4 1 The heater relay is de energized by the control u
36. 15V 15V VC 5V DMOC205SS VMOC205SS 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 is 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 _ Shapes of Electronic Components B Transistor E DTA123ES KRA101M Transistor B KRA223M 2SB910M EC KRC243M 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 panelis 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 PRESENTS
37. 245 F at which time the relay will be de energized turning off the fan motor Relay RY5 will however open as soon as the convection cycle has ended turning off the convection fan motor 5 Atthe end of the convection cook cycle shut off relay RY4 is energized turning on the damper motor The damper is returned to the open position closing the damper switch contacts which send a signal to the control unit de energizing shut off relay RY4 AUTOMATIC MIX COOKING CONDITION Touch the HIGH MIX ROAST or the LOW MIX BAKE pad DMOC205SS VMOC205SS first And then program desired cooking time by touching the Number pads The LOW MIX BAKE pad is preprogrammed for 350 F with 10 microwave power while the HIGH MIX ROAST pad is preprogrammed for 300 F with 30 microwave power When the START pad 15 touched the following operations occur 1 The numbers on the digital read out start to count down to zero 2 The shut off relays RY1 RY2 RY3 RY5 and RY6 are energized turning on the oven lamp turntable motor cooling fan motor and convection fan motor 3 The shut off relay RY4 is energized The damper door is closed from the open position 4 The heater relay RY3 is energized applying the main supply voltage to the heating element 5 Now the oven is in the convection cooking condition 6 When the oven temperature reaches the selected temperature the following operations occur 6 1 The power supply voltage is alterna
38. 6 OPERATION u aan 8 TROUBLEESHOOTINGGQGUIBE x aa bte Texas once ste 14 TESTEPROGEDUHE unu m etx En Amauta E Ed E Me es Ac EO CLE 16 TOUCH CONTROL PANEL ASSEMBLY nsns sna nass asas assa sas 23 COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE 0020 0 0 00 29 PIGTORIAEDIAGRAM i 36 POWER 37 PRINTED WIRING BOARD qalas 38 PARTS IST A 39 PACKING AND ACCESSORIES 44 This document has been published to be used for after sales service only Range Corporation The contents are subject to change without notice 111 Front St Greenwood MS 38930 Tel 888 845 4641 DMOC205SS VMOC205SS PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY a Do not operate or allow 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 sur
39. ARDA 8200 2 Place the oven tray in the oven cavity Place the load of 275215 ml of tap water initially at 20 5 C in the center of the oven cavity The water container shall be a low form of 600 ml beaker with an inside diameter of approx 8 5 cm 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 Close the door and set the time cooking for several minutes And start the oven If the water load is depleted replace it 35 Leakage test Leakage Test with Enclosure Installed 1 Grasp the probe of the survey instrument and hold it perpendicular to the gap between the door and the body of the oven Movethe probe slowly not faster than 2 5cm sec along the gap watching for the maximum indication on the meter Check for leakage at the door screen sheet metal seams and other accessible positions where the continuity of the metal has been breached eg around the switches indicator and vents Measure carefully at the point of highest leakage and make sure that the highest leakage is no greater than 4mW em and that the primary interlock switch does turn the oven OFF before any door movement Leakage Test without Enclosure 1 Remove the enclosure cabinet 2 Grasp the probe of the survey meter and hold it perpendicular to all mechanica
40. Grasp the probe ofthe survey instrument and hold it perpendicular to the gap between the door and the body of the oven 2 Move the probe slowly not faster than 2 5 cm sec along the gap watching for the maximum indication on the meter 3 Check for leakage at the door 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 door pull the door away from the front of the oven as far as is permitted by the closed latch assembly Measure carefully at the point of highest leakage and make sure that the highest leakage is no greater than 4mW cm and that the secondary interlock switch does turn the oven OFF before any door movement 4 C Leakage test without enclosure 1 Remove the enclosure cabinet 2 Grasp the probe of the survey instrument and hold it perpendicular to all mechanical and electric parts of the oven that is accessible to the user of the oven including but not limited to the waveguide cavity seams magnetron gap between the door and the body of the oven 3 Move the probe slowly not faster than 2 5 cm sec along the gap watching for the maximum indication on the meter 4 Measure carefully at the point of highest leakage and make sure that the highest leakage is under 5mW cm CAUTION Special attention should be given to avoid electrical shock because HIGH VOLTAGE is generated dur
41. KE cycle the damper is returned to the open position and the oven will go to the off condition The cooling fan will remain on until the oven has cooled COMPU DEFROST COOKING The COMPU DEFROST key is a special function key to defrost meats and poultry faster and better COMPU DE FROST automatically defrosts roast beef etc When the COMPU DEFROST is selected and the food weight is entered by using the COMPU DEFROST pad the oven will cook according to the special cooking sequence FIRE SENSING FEATURE MICROWAVE MODE This model incorporates a sensing feature which will stop the oven s operation if there is a fire in the oven cavity during microwave cooking This is accomplished by the LSI repeatedly measuring the voltage across the temperature measurement circuit ther mistor during it s 32 seconds time base comparing the obtained voltage measurements If the most recent voltage measured is 300mV greater than the previous voltage measured the LSI judges it as a fire in the oven cavity and switches off the relays to the power transformer fan motor and convection motor The LSI also stops counting down and closes the damper door so that no fresh air will enter the oven cavity Please referto the following section for a more detailed description Operation Please refer to the timing diagrams below 1 The thermistor operates within a 32 seconds time base and it is energized for three 3 seconds and off for 29 seconds Two 2
42. LLY THE MONITOR FUSE AND SWITCH ASSEMBLY IS PACKED WITH 20 AMPERE FUSE AND SWITCH l OVEN THERMAL CUT OUT on the side of steam duct A continuity check across the thermal cut out terminals should indicate a closed circuit unless the temperature of the oven thermal cut out reaches approximately 302 F 150 C The thermal cut out reset automatically at approximately 266 F 130 C If the thermal cut out has operated under the normal condition replace the thermal cut out An open thermal cut out indicates overheating of the oven cavity 17 DMOC205SS VMOC205SS PROCEDURE LETTER TESTPROCEDURES COMPONENTTEST MAGNETRON THERMAL CUT OUT on the waveguide A continuity check across the thermal cut out terminals should indicate a closed circuit unless the temperature of the thermal cut out reaches approximately 257 F 125 C An open thermal cut out indicates overheating of the magnetron Check for restricted air flow to the magnetron through the vent holes of the oven cavity especially the cooling duct and cooling fan CAUTION IF THE THERMAL CUT OUT INDICATES OPEN CIRCUIT AT ROOM TEMPERATURE REPLACE THE THERMAL CUT OUT CONVECTION CUT OUT on side of the heater duct A continuity check across the thermal cut out terminals should indicate a closed circuit unless the temperature of thermal cut out reaches 302 F 150 C The thermal cut out resets automatically at approximately 266 F 130 C If the thermal cut out has operate
43. ME LEVEL TIME LEVEL TIME 0 5lbs 70 47sec 0 52sec 50 32sec 30 40sec 5 If improper operation is indicated the control unit is probably defective and should be checked 20 DMOC205SS VMOC205SS TESTPROCEDURES PROCEDURE LETTER COMPONENT TEST T PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING BOARD PWB IS OPEN To protect the electronic circuits this model is provided with a fine foil pattern added to the primary on the PWB this foil pattern acts as a fuse If the foil pattern is open follow the troubleshooting guide given below for repair Problem POWER ON indicator does not light up STEPS OCCURRENCE CAUSE OR CORRECTION 1 The rated voltage is not applied to POWER Check supply voltage and oven power cord terminal of CPU connector CN A 2 The rated voltage is applied to primary side Power transformer or secondary circuit defective of power transformer Check and repair 3 Only pattern at a is broken Insert jumper wire J1 and solder 4 Pattern at a and b are broken Insert the coil RCILF2003YAZZ between and Cu NOTE Atthe time of making these repairs make a 2 i S visual inspection of the varistor Check for d 2 burneddamage and examine the transformer 3 with an ohmmeter for the presence of layer 4 b short circuit check the primary coil resist
44. R THERMISTOR DAMPER MOTOR DAMPER SWITCH TOUCH CONTROL PANEL KEY UNIT RELAY RY 1 RELAY RY 2 RELAY RY 3 RELAY RY 4 RELAY RY 5 RELAY RY 6 FOIL PATERN ON PWB AH SENSOR OVEN LAMP OR SOCKET FAN MOTOR TURNTABLE MOTOR CONVECTION MOTOR LOOSE WIRING SHORTED IN POWER CORD NO POWER AT OUTLET LOW VOLTAGE NOISE FILTER 15 DMOC205SS VMOC205SS PROCEDURE LETTER A TESTPROCEDURES COMPONENTTEST MAGNETRON ASSEMBLY TEST HIGH VOLTAGES ARE PRESENT DURING THE COOK CYCLE SO EXTREME CAUTION SHOULD BE OBSERVED DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPONENTS OR WIRING To test for an open 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 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 silicon rectifier high voltage capacitor and power transformer This test will require a 16
45. REPLACEMENT AND ADJUSTMENT PROCEDURE CAUTION DISCONNECT OVEN FROM POWER SUPPLY BEFORE REMOVING OUTER CASE DISCHARGE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPONENTS OR WIRING AFTER REMOVING OUTER CASE WARNING FOR WIRING To prevent an electric shock take the following man ners 1 Before wiring 1 Disconnect the power supply 2 Open the door and wedge the door open 3 Discharge the high voltage capacitor and waitfor 60 3 Sharp edge Bottom plate Oven cavity Weveguide flange Chassis support and other metallic plate 4 Movable parts to prevent a fault Fan blade Fan motor Switch Switch lever Open button seconds 3 Do not catch the wire leads in the outer case cabinet 2 Don t let the wire leads touch to the followiong parts 4 Insert the positive lock connector certainly until its pin 1 High voltage parts islocked And make sure thatthe wire leads should not Magnetron High voltage transformer High voltage come off even if the wire leads is pulled capacitor and High voltage rectifier assembly 5 To prevent an error function connect the wire leads 2 Hot parts Convection heater Oven lamp Magnetron High voltage transformer and Oven cavity correctly referring to the Pictorial Diagram 1 OUTER CASE REMOVAL To remove the components procedure as follows Disconnect oven from power supply it from retaining clips on the cavity face plate 4 Lift entire case from the unit
46. RTRN A527WREO Power transformer RC QZA173WREO H V capacitor RC QZA211WREO H V capacitor Interchangeable FH DZAO53WRKO H V rectifier assembly RV MZA222WREO0 Magnetron RV MZA114WREO Magnetron Interchangeable RMOTDA222WREO0 Turntable motor FDTCTA183WRKO AH sensor assembly CABINET PARTS GCABUA721WRPO Outer case cabinet TMAPCA733WRRO Schematic diagram FDAI A180WRYO Base cabinet Not Replaceable GLEGPAO19WREO Foot GCABDAO88WRWO Rear cabinet Not Replaceable LHLDKAOO09WRFO Cord holder LBNDKAO36WRPO Capacitor holder FHNG A320WRMZ Oven hinge Lower PHOK A112WRFO Latch hook MLEVPA131WRFO Switch lever GCOVHA34 7WRPO Turntable motor cover PCOVPA171WRPO CSA barrier CONTROL PANEL PARTS gt 4 DPWBFC189WRUZ Control unit 1 3 2 FPNLCB458MRKO Control panel frame with key unit DMOC205SS 1 3 2 FPNLCB459MRKO Control panel frame with key unit VMOC205SS 1 3 2 4 FUNTKA393WREO Key unit DMOC205SS 1 3 42 FUNTKA3 94WREO Key unit VMOC205SS i de 222 JBTN B164WRFO Open button DMOC205SS 1 2 2 JBTN B165WRF0 Open button VMOC205SS 1 223 MSPRCA045WREO Open button spring 1 3 3 LANGTA340WRWO Control panel back plate 1 3 4 FANGTAO93WRKO Open lever 1 ELS NSFTTAOA42WREO Open shaft 1 3 6 XEPSD30P10XS0 Screw control unit mtg 3 3 7 XCPSD40P12000 Screw control panel back plate mtg 3 3 8 LX CZBO19MREO Screw control pane
47. SOR u gt THIRD DOOR MISTOR SWITCH D SWITCH I 5 777 777 Figure O 4 Oven Schematic Convection Cooking Condition 12 DMOC205SS VMOC205SS DESCRIPTION AND FUNCTION OF COMPONENTS DOOR SENSING AND PRIMARY INTERLOCK SWITCHES The door sensing switch in the secondary interlock system is mounted in the upper position on the latch hook the primary interlock switch is mounted in the lower position on the latch hook They are activated by the latch heads on the door When the door is opened the switches interrupt the circuit to all components A cook cycle cannot take place until the door is firmly closed thereby activating both interlock switches The secondary interlock system consists of the door sensing switch and secondary interlock relay located on the control circuit board p LATCH HOOK _ THIRD DOOR SWITCH DOOR SENSING SWITCH MONITOR SWITCH LATCH HEADS PRIMARY INTERLOCK SWITCH SWITCH LEVER OPEN LEVER DOOR OPEN BUTTON in Figure D 1 Door sensing switch monitor switch third door switch and primary interlock switch MONITOR SWITCH The monitor switch is mounted on the middle position of latch hook It is activated the contacts opened by the lower latch head while the door is closed The switch is intended to render the oven inoperative by means of blowing the monitor fuse when the contacts of the relay RY1 and primary interlock switch fail to open whe
48. URE LETTER COMPONENT TEST Ifthe capacitor is open no high voltage will be available to the magnetron Disconnect input leads and check for short or open between the terminals using an ohmmeter Checking with a high ohm scale if the high voltage capacitor is normal the meter will indicate continuity for a short time and should indicate approximately 10 MQ once the capacitor is charged If the 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 E PRIMARY INTERLOCK SWITCH AND THIRD DOOR SWITCH TEST Isolate the switch and connect the ohmmeter to the common COM and normally open NO terminal of the switch The meter should indicated an open circuit with the door open and a closed circuit with the door closed If improper operation is indicated replace the switch F SECONDARY INTERLOCK SYSTEM TEST DOOR SENSING SWITCH Isolate the switch and connect the ohmmeter to the common COM and normally open NO terminal of the switch The meter should indicated an open circuit with the door open and a closed circuit with the door closed If improper operation is indicated replace the door sensing switch SECONDARY INTERLOCK RELAY Disconnect two 2 wire leads from the tab terminal of the secondary interlock relay RY2 Check the state of the relay contacts using a ohmmeter The relay contacts should be open If the relay contacts are closed repla
49. VIKING VMOC205SS SERVICE MANUAL S14M227DM0205 MICROWAVE OVEN moves DMOC205SS VMOC205SS VMOC205SS model shown In the interest of user safety the oven should be restored to its original condition and only parts identical to those specified should be used WARNING TO SERVICE PERSONNEL 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 Inverter unit that includes High Voltage Capacitor High Voltage Power Transformer High Voltage Rectifier and Heat sink etc and Magnetron High Voltage Harness etc TABLE OF CONTENTS Page PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY INSIDE FRONT COVER BEFORE SERVICING iiie e ee ses eei INSIDE FRONT COVER WARNINGTOSERVIGEPERSONNEL u uluya Dee 2 MICROWAVE MEASUREMENT PROCEDURE Canada iii 3 MICROWAVE MEASUREMENT PROCEDURE USA nennen nnne nennen ener nennt nennen 4 elsi eisipP BA AZMNMCOHRCH O 5 PRODUCTSPECIFICATIONSE 6 GENERAL 000 0 0
50. WRPO PCUSUA1 96WRPO PCUSUA4 2 5WRPO PCUSGA3 53WRPO PSKR A171WRWO PFPF AO64WREO PCOVPA3 04WRPO FCOV B255MRKO FCOV B254MRKO DDORFA820WRYO GCOVHA155WRFO LANGKA851WRTO LSTPPA169WRFO MSPRTAO81WREO LANGKA918WRWO LANGKA919WRWO XCPSD40P08000 XEPSD30P08000 PCUSGA53 7WRPZ A088WRMO FAMI A087WRMO FW VZB342WREO FW VZB604WREO OW OZA198WREO QW VZA108WREO TCAUAA196WRRO TCAUABO34MRRO TINSEB363MRRO TINSEB364MRRO LHLDWA013WREO TCAUHBO08MRRO TCAUSBO12MRRO TCAUAB0O48MRRO TINSEB322MRRO TCADCBO16MRRO TCAUABO33MRRO XOTWW40P10000 XOTSE40P12000 XCTWW40P08000 XHTSD40PO8RVO LX CZ0052WREO XWVSD60 07000 LX WZAOO4WREO LX CZA020WREO XBPSD30P14K00 XBPSD40P25000 Steam duct assembly Damper cam Damper shaft Damper door ass y Damper duct Cushion Turntable coupling Waveguide cover Cushion Light glass Thermal protection sheet Right Thermal protection plate Right Air guide Bottom Air guide Right Convection motor mounting plate Pulley M Fan blade Cooling fan duct Chassis support Oven hinge Upper Convection fan belt Noise unit angle Cushion Damper duct cushion Cushion Magnetron air guide Thermal protection sheet Thermo cover DOOR PARTS Door panel assembly complete Door panel assembly complete Door panel Choke cover Latch angle Latch head Latch head spring Thermal plate U Thermal plate R Screw 4mm x 8mm Screw 3mm x 8mm Cushion MISCELLANEOUS
51. ce the circuit board entirely or the relay itself G MONITOR SWITCH Disconnect the oven from power supply Before performing this test make sure that the primary interlock switch and the secondary interlock relay are operating properly according to the above Test Procedures Disconnect the wire lead from the monitor switch NC terminal Check the monitor switch operation by using the ohmmeter as follows When the door 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 door opened in this condition the plunger of the monitor switch is pushed in the meter should indicate an open circuit If improper operation is indicated the switch may be defective After testing the monitor Switch re connect the wire lead to the monitor switch NC terminal and check for continuity of monitor circuit SCREW DRIVER PRIMARY INTERLOCK OHMMETER SWITCH H BLOWN MONITOR FUSE If the monitor fuse is blown when the door is opened check the primary interlock switch door sensing switch relay RY1 and monitor switch according to the TEST PROCEDURE for those switches before replacing the blown monitor fuse CAUTION IF THE MONITOR FUSE IS BLOWN BY IMPROPER SWITCH OPERATION THE MONITOR FUSE AND SWITCH MUST BE REPLACED WITH MONITOR FUSE AND SWITCH ASSEMBLY PART NUMBER FFS BA012WRKO EVEN IF THE MONITOR SWITCH OPERATES NORMA
52. d for return in the shipping carton with its cushion material in which the new replacement part was shipped to you 19 DMOC205SS VMOC205SS PROCEDURE LETTER Q TESTPROCEDURES COMPONENTTEST KEY UNIT TEST 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 door sensing switch stop switch operates properly that is the contacts are closed when the door is closed and open when the door 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 door sensing switch is closed either close the door or short the door sensing switch connecter Use the key unit matrix indicated on the control panel schematic and place a jumper wire between the pins that correspond to the STOP CLEAR pad making momentary contact If the control unit responds by clearing with a beep the key unit is faulty and must be replaced If the control unit does not respond it is a 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 at TAUR por Al Sa 009 senses conve ror tet G POPCORN PREHEAT CONVEC rs 5 om pas G 2 REHEAT COOK SAKE M
53. d under the normal condition replace the thermal cut out An open thermal cut out indicates overheating of heater unit check for restricted air flow to the heater unit through the vent hole of the oven cavity especially the heater duct and convection fan HEATING ELEMENT TEST Make sure the heating element is fully cooled and test as follows a Disconnect wire leads and measure the resistance with an ohmmeter On the R x 1 scale the resistance between the heating element terminals should be approximately 10 20 b Disconnect wire leads and measure the insulation resistance with 500V 100MQ insulation resistance meter The insulation resistance between heating element terminal and cavity should be more than 0 5 THERMISTOR TEST Disconnect connector E from the control unit Measure the resistance of the thermistor with an ohmmeter Connect the ohmmeter leads to Pin No s E 3 and E 4 Room Temperature Resistance 68 20 86 30 Approx 350kO 155KO If the meter does not indicate above resistance replace the thermistor DAMPER MOTOR TEST When the power cord is plugged into the wall receptacle and 117 volts A C is supplied to the damper motor the motor operates until the damper is opened and the damper switch closes Then the damper motor stops operation If the damper motor does not operate check for A C voltage with a voltmeter at the motor 1 Disconnect the power cord from the wall
54. e two 2 screws and nuts holding the fan motor to the fan duct 17 Now the fan motor is free INSTALLATION 1 Install the fan motor to the fan duct with the two 2 screws and nuts Install the fan blade to the fan motor shaft according the following procedure 1 Hold the center of the bracket which supports the shaft of the fan motor on the flat table 2 Apply the screw lock tight into the hole for shaft of the fan blade 3 Install the fan blade to the shaft of fan motor by pushing the fan blade with a small light weight ball peen hammer or rubber mallet CAUTION Do not hit the fan blade strongly when installed 2 i are the positions that should be pinched because the bracket may be disfigured Make sure that the fan blade rotates smooth after installation Make sure that the axis of the shaft is not slanted Reset the fan duct assembly to its place Install the tabs of fan duct to the rear cabinet and air guide Install the magnetron air guide with the one 1 screw Reinstall the main harness and thermistor harness to each hole of the fan duct Reinstall the chassis support to the control panel back plate waveguide and rear cabinet with the three 3 Screws Re connect the wire leads to the fan motor referring to the pictorial diagram Re install the fan motor gro
55. ee 70 P 90 P 80 P 70 P 60 P 50 P 40 P 30 P 20 P 1 0 P 0 the signal tu rns to 40 approx 40 power 16 16 sec level L level in repetition according approx 30 power 12 sec 20 sec to the power level P 20 approx 20 power 8 sec 24 sec P 10 approx 10 power 6 sec 26 sec P 60 approx 60 power 22 sec 10 sec P 50 approx 50 power 18 sec 14 sec P 0 0 power 0 sec 32 sec DMOC205SS VMOC205SS EL signal WO eE OO Damper motor driving signal To turn on and off shut off relay RY4 Heating element driving signal To turn on and off shut off relay RY3 L level during convection cooking H level otherwise lt Dui During convection cooking the signal becomes H Convection level when the temperature of the oven cavity exceeds the predetermined temperature P46 P45 Terminal not used P44 Timing signal output terminal for temperature measurement OVEN THERMIS TOR H level GND Thermistor OPEN timing L level 5V Temperature measuring timing Convection cooking Signal to sound buzzer A key touch sound B Completion sound C When the temperature of the oven cavity reaches the preset temperature in the preheating mode or when the preheating hold time 30 minutes is LILI elapsed Timing signal output terminal for temperature measurement OVEN
56. ens 1 mae ete 5 Hire z Hire Z E more Z 1 D 87 7 K 59 eye Lee pog 5 se mz 704 e 8 Z ewe eec R64 Qv R47 xs 5 2 00 e m ie a 4 Ses blk Sy ec z 4 Ex 8 z z 515155 Lie E CONV HEATER COM RED BRN paH 1L pen E g z UI 5 ao 92 RY3 5 23 29 go z 8 RY2 2 ez x dz m a3 226 m BA gt 5 2 lt 5 2 l 5 a 2 gt Figure 5 3 Printed Wiring Board 3 4 38 DMOC205SS VMOC205SS PARTS LIST eRefer to IMPORTANT described at end of parts list REF NO PARTNO DESCRIPHION 2 ELECTRICAL PARTS Power supply cord Monitor fuse 20A and monitor switch V 5220D 070 assembly FACCDAO74W FFS BAO12W FPWBFA293W OSW MA110W FH HZA041W OSW MA110W Noise filter Primary interlock switch Thirdoor switch Door sensing switch Thermistor Damper switch Magnetron thermal cut out 125 C Oven amp Convection thermal cut out 150 C Damper motor Oven lamp Oven lamp Interchangeable Oven lamp socket Convection fan motor RTHM A116W RTHM A085W RMOTDA192W RLMPTA077W RLMPTA027W QSOCLA021W RMOTEA283W O O O O UI d amp N n BP 1 H 1 H RMOTEA300WREO Fan motor RHET A136WREO0 Heating element
57. faces 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 compartments 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 Viking Service immediately 1 888 845 4641 If the unit operates with the door open service person should 1 tell the user not to operate the oven and 2 contact VIKING plus the Department Of Health Canada and or the Food and Drug Administration s Center for Devices and Radiological Health immediately Service personnel should inform VIKING of any certified unit found with emissions in excess of 4mW cm Theownerofthe unit should be instructed notto
58. fter approximately 3 seconds the display shows X X X X which is the remaining cooking time and the display count down If the above is not the case the control unit is probably defective If the above is proper the AH sensor is probably defective 210000 1 2 3 4 5 6 Plunger R1 R2 220 1 1 2W 4 4 3kQ 5 1 4W NC R4 1MQ 5 1 4W NO T tor F Cantol unl 4 1 4 F4 lt l 2 NO F2 c 14 R1 F 3 c w W CONNECTOR R22 R3 R4 Sensor Dummy Resistor Circuit 22 DMOC205SS VMOC205SS TOUCH CONTROL PANEL ASSEMBLY OUTLINE OF TOUCH CONTROL PANEL The touch control section consists of the following units as shown in the touch control panel circuit 1 Key Unit 2 Control Unit The principal functions of these units and the signals communicated among them are explained below Key Unit The key unit is composed of a matrix signals P10 P17 generated in the LSI are sent to the key unit When a key pad is touched a signal is completed through the key unit and passed back to the LSI through R24 R27 to perform the function that was requested Control Unit Control unit consists of LSI power source circuit synchro nizing signal circuit ACL circuit buzzer circuit temperature measurement circuit absolute humidity sensor circuit and indicator circuit 1 LSI This LSI controls the temperature meas
59. he oven outer case 5 Door assembly is now free 2 Note When the individual parts replaced refer to y H 2 Remove three 3 screws holding lower oven hinge Door Disassembly m 3 Remove the lower oven hinge from oven cavity bottom On re installing door insert the upper oven hinge into flange the door hinge pin Then while holding door in place 33 DMOC205SS VMOC205SS 7 Make sure the door is parallel with oven face lines left and upper side lines and door latch heads pass through latch holes correctly 8 Insert the lower oven hinge into oven cavity bottom flange and then engaged the door hinge pin Then secure the lower oven hinge firmly with tree 3 mounting screws Note After any service to the door A Make sure that door sensing switch and secondary interlock switch are operating properly Refer to chapter Test Procedures B An approved microwave survey meter should be usedto assure compliance with proper microwave radiation emission limitation standards DOOR ADJUSTMENT The door can be adjusted by keeping screws of each hinge loose After adjustment make sure of the following 1 Door 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 Door is positioned with its face pressed toward cavity face plate
60. he oven cavity 6 Remove two 2 screws holding heater duct to base cabinet Release two 2 snap bands holding wire harness to the thermal cover convection 7 The heater unit is now free HEATING ELEMENT REMOVAL 1 Remove two 2 screws holding heating element to heater duct 2 Loosen two 2 screws holding holders to heater duct and take heating element out of heating element holders 3 Heating element is free NOTE After installed the heating element completely bent top of the heating element holder to inside using by long nose pliers as shown following illustration Long nose plier Heating element Heating element holder OVEN LAMP AND LAMP SOCKET REMOVAL 1 Disconnect oven from power supply and remove outer case Discharge high voltage capacitor Bend the tab of the air guide holding the lamp socket Lift up the oven lamp socket Pull the wire leads from the oven lamp socket by pushing the terminal hole of the oven lamp socket with the small flat type screw driver 6 Now the oven lamp socket is free oR WP Oven lamp socket Flat type small screw driver Figure C 2 Oven lamp socket FAN MOTOR REMOVAL 1 Disconnect oven from power supply and remove outer case Discharge high voltage capacitor Disconnect the wire leads from the fan motor Remove one 1 screw holding the fan motor grounding wire to the air guide Right 5 Remove three 3 screws hold
61. he turntable motor Remove the two 2 screws holding the turntable motor and coupling mounting plate to the oven cavity bottom Turntable motor Coupling mounting plate and Thermal protection plate bottom will be free DAMPER ASSEMBLY REMOVAL Disconnect oven from power supply and remove outer case Discharge the high voltage capacitor Disconnect wire leads from damper motor and damper switch Remove two 2 oven side screws holding damper motor angle to thermal protection plate right Damper assembly is free Removeone 1 screw holding damper motor to damper motor angle and one 1 screw holding damper switch to damper motor angle Damper motor and switch are free DMOC205SS VMOC205SS HEATER UNIT ASSEMBLY REMOVAL HEATING ELEMENT CONVECTION FAN CONVECTION MOTOR THERMISTOR THERMISTOR REMOVAL 1 Disconnect oven from power supply and remove outer case cabinet 2 Discharge the high voltage capacitor Disconnect wire leads from H V capacitor and remove four 4 screws holding rear cabinet to bottom plate and three 3 screws holding to heater unit assembly and two 2 screws holding steam duct to top of oven cavity Disconnect wire leads from power supply cord terminals 3 Disconnect wire leads from thermistor Remove two 2 screws from thremistor 4 Disconnect wire leads from convection motor thermal cut out and heater element 5 Remove nine 9 screws holding heater duct to t
62. hen the control unit causes the heater relay to operate thus the current to the heating element is turned ON OFF MAGNETRON THERMAL CUT OUT The thermal cut out located on the waveguide is designed to prevent damage to the magnetron if an over heated condition develops in the magnetron due to cooling fan failure obstructed air guide dirty or blocked air intake etc Under normal operation the thermal cut out remains closed However when abnormally high temperatures are reached within the magnetron the thermal cut out will open at 257 F 125 C causing the oven to shut down magnetron thermal cut out is not reset at room temperature OVEN THERMAL CUT OUT The thermal cut out located on the side of the steam duct is designed to prevent damage to the unit if the foods in the oven catch fire due to over heating produced by improper setting of cooking time or failure of control unit Under normal operation the thermal cut out remains closed However when abnormally high temperatures are reached within the oven cavity the thermal cut out will open at 302 F 150 C causing the oven to shut down When the thermal cut out has cooled the thermal cut out closes at 266 F 130 C CONV THERMAL CUT OUT The thermal cut out located on the left side of the thermal protection plate left is designed to prevent damage to the heater unit if an over heated condition develops in the tube due to cooling fan failure obstructed air ducts dirty
63. ing the chassis support to the rear cabinet waveguide and control panel back plate 6 Remove the chassis support from the oven 7 Remove one 1 screw holding the magnetron air guide to the waveguide 8 Remove the magnetron air guide from the waveguide 9 Disconnect wire leads from the fan motor 10 Release the main harness from the hole of the fan duct 11 Release the thermistor harness from the hole of the fan duct 12 Release one 1 tab holding the fan duct to the rear cabinet 13 Release one 1 tab holding the fan ductto the air guide Right D 14 Remove the fan duct assembly from the oven 15 Remove the fan blade from the fan motor shaft according the following procedure 1 Hold the edge of the rotor of the fan motor by using a pair of grove joint pliers CAUTION Make sure that any pieces do not enter the gap between the rotor and the stator of the fan motor because the rotor is easily shaven by pliers and metal pieces may be produced Do not touch the pliers to the coil of the fan motor because the coil may be cut or injured Do not disfigure the bracket by touching with the pliers 2 Remove the fan blade from the shaft of the fan motor by pulling and rotating the fan blade with your hand 3 Now the fan blade will be free CAUTION Donotuse this removed fan blade again because the hole for shaft of it may become bigger than a standard one DMOC205SS VMOC205SS 16 Remove th
64. ing this test No Load test 1 Operate the oven without a load and measure the leakage by the same method as the above test procedure Leakage test with enclosure installed 2 Make sure that the highest leakage should not exceed 5mW cm NOTE After servicing record data on service invoice and microwave leakage report DMOC205SS VMOC205SS A 1 19 MICROWAVE MEASUREMENT PROCEDURE USA Requirements 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 sta
65. k 6 Safety door latches 14 Turntable motor shaft The oven will not operate unless the dooris 15 Power supply cord securely closed TOUCH CONTROL PANEL VMOC205SS DMOC205SS VMOC205SS OPERATION DESCRIPTION OF OPERATING SEQUENCE The following is a description of component functions during oven operation OFF CONDITION Closing the door activates the door sensing switch and secondary interlock switch In this condition the monitor switch contacts are opened When oven is plugged in 117 volts A C is supplied to the control unit Figure O 1 1 The display will show WELCOME PRESS CLEAR To set any program or set the clock you must first touch the STOP CLEAR pad The display will clear and will appear NOTE When the door is opened the oven lamp comes on 2 A signal is input to the control unit energizing the coil of shut off relay RY 4 RY4 contacts close completing a circuit to the damper motor The damper motor now operates moving the damper to the open position thereby closing the contacts of the damper switch inputs a signal to the control unit The coil of relay RY 4 is de energized opening its contacts thereby turning off the damper motor COOKING CONDITION Program desired cooking time Variable Cooking Control by touching the NUMBER pads and the power level pad When the START pad is touched the following operations occur 1 The contacts of relays are closed and components
66. l and eleeectronic parts of the oven that is accessible to the user of the oven including but not limited to the waveguide cavity cavity seams magnetron and magnetron to waveguide connection Move the probe slowly not faster than 2 5cm sec watching for the maximum indication on the meter Measure carefully at the point of highest leakage and make sure that the highest reading is under the required limit as mentioned above CAUTION Special attention should be given to avoid electrical shock because HIGH VOLTAGE is generated during this test No Load Test 1 Operate the oven without a load and mesure the leakage by the same method as the above test procedure A Test Enclosure Installed Make sure that the highest leakage should not exceed 5mW cm Note Do not perform this test for extended periods 2
67. l down on the positive lock connector CAUTION WHEN YOU CONNECTING THE POSITIVE LOCK CONNECTORS TO THE TERMINALS INSTALL THE POSITIVE LOCK SO THAT THE LEVER FACES YOU Disconnect high voltage wire lead of capacitor from transformer Remove one 1 screw and washer holding the rectifier from the capacitor holder Remove one 1 screw holding the capacitor holder to the rear cabinet Remove the capacitor from the holder Terminal Positive lock connector Lever Figure C 1 Positive lock connector CONVECTION MOTOR REMOVAL Disconnect oven from power supply and remove outer case Discharge the high voltage capacitor Disconnect wire leads from the convection motor Remove the convection fan belt Remove two 2 screws holding the convection motor mounting angle to the heater duct and base cabinet Take out the convection motor assembly from the unit The convection motor assembly is now free Remove two 2 screws and nuts holding the motor to mounting angle Remove pulley M from the motor shaft Convection motor is now free TURNTABLE MOTOR REMOVAL Disconnect the oven from power supply Remove the turntable tray and the turntable support out of the oven cavity Turn the oven upside down and remove one 1 screw holding the turntable motor cover to the base plate and take off the turntable motor cover Disconnect wire lead from t
68. l mtg 2 3 9 XOTSD40P12RVO Screw power unit assy 2 OVEN PARTS FOVN A314WRYO Oven cavity assembly Not Replaceable FROLPAO72WRKO Turntable support NTNT AO19WRHO Turntable tray FBRGMAO02WREO Bearing ass y PREFHAO28WRWO Thermal protection plate LANGTA196WRWO Bearing mounting plate LBNDK0054WREO Heater element holder LFIX A013WRWO Bearing holder plate PNPRPRPRPER NFANMAO19WRWO Convection fan NPLYBA020WRF0 Pulley F FDUC A279WRKO Heater duct assembly PFPF A138WREO Thermal protection sheet LANGKA723WRPO Glass mounting plate AN 1 PRR N H Lo J O U P W NH gt 1 PCUSUA167WRP0 PCUSUAA424WRPO Cushion Cushion BNHBpBHH DMOC205SS VMOC205SS REF NO PART NO DESCRIPTION 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 dao EG d Gd O O N H 6 1 6 2 6 3 6 4 6 5 6 6 6 7 6 8 6 9 6 9 6 10 6 11 6 12 6 13 6 14 6 15 6 16 1 1 1 1 1 1 1 1 1 pow 6 v do d O 1 O L O Ui amp amp N F H FDUC A323WRWO MCAMPA03 0WRFO NSFTTA114WREO FFTA A034WRKO PDUC A269WRWO PCUSGA398WRPO NCPL AO21WRFO PCOVPA301WREO PCUSUA197WRPO PGLSPAA455WREO PFPF A139WREO PREFHAO53WRWO PSKR A153WRWO PSKR A323WRWO LANGQA4 0 7WRWO NPLYBAO21WRFO NFANJAO20WREO PDUC A270WRFO LANGFAO 8 9WRWO MHNG A520WRMZ NBLTKAOO5SWREO LANGQA4 74
69. m ins RS ne G1 wer K rower ster erem KEY UNIT RELAY TEST Remove the outer case and check voltage between Pin Nos 7 and 9 of the 9 pin connector A on the control unit an A C voltmeter The meter should indicate 120 volts if not check the oven circuitry Shut off Cook and Heater Relay Test These relays are operated by D C voltage Check voltage atthe relay coil with a D C voltmeter during the microwave cooking operation or convection 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 RELAY SYMBOL OPERATIONAL VOLTAGE CONNECTED COMPONENTS RY1 Approx 19 0V D C Oven lamp Turntable motor RY2 COOK Approx 18 0V D C Power transformer RY3 HEATER Approx 18 0V D C Heating element RY4 Approx 19 0V D C Damper motor RY5 Approx 19 0V D C Convection motor RY6 Approx 19 0V D C Cooling fan motor COMPU DEFROST TEST 1 Place one cup of water in the center of the turntable tray in the oven cavity 2 Close the door touch the DEFROST pad twice and touch the Number pad 5 And then touch the START pad 3 After 2 sec Now the oven is in DEFROST cooking condition 4 The oven will operate as follows WEIGHT 1ST STAGE 2ND STAGE 3RD STAGE 4TH STAGE LEVEL TIME LEVEL TI
70. mper opened H level signal OV GND Damper closed L level signal 5V Temperature measurement input OVEN THERMISTOR By inputting DC voltage corresponding to the temperature detected by the thermistor this input is converted into temperature by the A D converter built into the LSI Digit selection signal The relationship between digit signal and digit are as follows Digit signal Digit Normally one pulse is output in every period and inputto the grid of the Fluores cent Display Oven lamp and turntable motor driving signal Square Waveform 60Hz To turn on and off the shut off relay RY1 167 msec The square waveform voltage is delivered to TUL the relay RY1 driving circuit Convection motor driving signal To turn on and off shut off relay RY5 L PE esp level during CONVECTION H level other on L_ Convection wise Cooling fan motor driving signal To turn on and off shut off relay RY6 L During level during both microwave and convection cooking cooking H level otherwise Magnetron high voltage circuit driving si nal VARI MODE ONTIME OFF TIME To turn on and off the cook relay RY2 In 100 32 sec 0 sec operation the signals holds L level 99 approx 90 power 0 m during microwave cooking and H level P 0 80 power 26 896 see while not cooking In other cooking modes 270 G
71. n plugged in at least five minutes before checking sensor cook operation The cabinet should be installed and screws tightened 1 Fill approximately 200 milliliters 7 2 oz of tap water in a 1000 milliliter measuring cup 2 Place the container on the center of tray in the oven cavity 3 Close the door 4 Touch SENSOR COOK pad and number pad 1 Now the oven is in the sensor cooking condition and BAKED POTATO will appear in the display b Touch Start pad The oven will operate for the first 16 seconds without generating microwave energy 21 DMOC205SS VMOC205SS PROCEDURE LETTER TESTPROCEDURES COMPONENTTEST When the AH sensor is defective open or short Error will appear in the display after 16 seconds cleaning time If ERROR appears check sensor wire connections and or AH sensor 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 and the display should start to count down the remaining cooking time and oven should turn off after water is boiling bubbling If the oven does not turn off replace the AH sensor or check the control unit refer to explanation below 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 oven from power supply and remove outer case 2
72. n the door is opened Functions 1 When the door is opened the monitor switch contact close to the ON condition due to their being normally closed At this time the door sensing and primary interlock and third door switches are inthe OFF condition contacts open due to their being normally open contact switches 2 As the door goes to a closed position the monitor switch contacts are first opened and then the door sensing switch third door switch andthe primary interlock Switch contacts close On opening the door each of these switches operate inversely Ifthe door 15 opened and the relay RY1 and the primary interlock switch contacts fail to open the monitor fuse blows simultaneously with closing of the monitor switch contacts CAUTION BEFORE REPLACING A BLOWN MONITOR FUSE TEST THE DOOR SENSING SWITCH PRIMARY INTERLOCK SWITCH RELAY RY 1 AND MONITOR SWITCH FOR PROPER OP ERATION REFER TO CHAPTER TEST PRO CEDURE NOTE MONITOR FUSE AND MONITOR SWITCH ARE REPLACED AS AN ASSEMBLY 13 THIRD DOOR SWITCH The switch is activated by the latch heads while the door is closed When the door is opened the switch interrupt the circuit to the power transformer This switch prevents power transformer engaging and microwave when the door opened THERMISTOR The thermistor is a negative temperature coefficient type The temperature in the oven cavity is detected through the resistance of the thermistor and t
73. ndard for microwave ovens 21 CFR 1030 10 c 3 i must be used for testing 2 3 C Place the oven tray in the oven cavity Place the load of 275215 ml 9 8 oz of tap water initially at 20 5 C 68 F in the center of the oven cavity The water container 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 Set the cooking control on Full Power Cooking Mode Close the door 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 Leakage test Closed door leakage test microwave measurement 1 2 3 4 Grasp the probe of the survey instrument and hold it perpendicular to the gap between the door and the body of the oven 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 Check for leakage the door 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 door pull the door away from the front of the oven as far as is permitted by the closed latch assembl
74. ng time and the timer counts down to zero At this time the door may be opened to stir food turn it or season etc 6 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 7 Openingthe doorortouchingthe STOP CLEAR pad the time of day will reappear on the display and the oven will revert to an OFF condition COMPU BROIL COMPU ROAST COMPU BAKE COMPU BROIL ROAST BAKE will automatically compute the oven temperature microwave power and cooking time for baking roasting and broiling Setthe desired program by touching the COMPU BROIL ROAST BAKE pad and number pad Enter the weight by touching the Number pads When the START pad is touched the following operations occur 1 The COOK indicator will light and the Convection Fan Symbol will rotate 2 The cooking time will appear on the display and start counting down to zero The cooking time is adjusted automatically according to the weight of the food 3 The shut off relays RY1 RY5 and RY6 are energized turning on the oven lamp turntable motor cooling fan motor and convection motor The power supply voltage is applied to the heating element 10 4 Now the oven is in the convection cooking mode 5 Whentheoventemperature has reachedthe programmed convection temperature the oven goes into the programmed cooking mode 6 Atthe end of the COMPU BROIL ROAST BA
75. nit temperature circuit and thermistor opening the circuit to the heating element 4 2 The oven will continue to function for 30 minutes turning the heater on and off as needed to maintain the selected preheat temperature The oven will shut down completely after 30 minutes CONVECTION COOKING CONDITION Whenthe preheattemperature is reached a beep signal will sound indicating that the holding temperature has been reached in the oven cavity Open the door and place the food to be cooked in the oven Touch the CONVEC pad first and then touch the Tempera ture pad And program desired cooking time by touching the Number pads When the START pad is touched the following operations occur 1 The numbers on the digital read out start to count down to zero 2 The oven lamp turntable motor cooling fan motor and convection motor are energized 3 Heaterrelay is energized ifthe cavity temperature is lower than the selected temperature and the main supply voltage is applied to the heating elementto return to the selected cooking temperature 4 Upon completion of the cooking time the audible signal will sound and oven lamp turntable motor cooling fan motor and convection motor are de energized At the end of the convection cycle if the cavity air temperature is above 275 F the circuit to RY6 will be maintained by the thermistor circuit to continue operation ofthe cooling fan motor until the temperature drops below
76. of the oven does not exceed 1 1 0mW cm with the test load of 275 15 ml of water at an initial temperature 20 5 C 2 5 0mW cm when the outer enclosure is removed with a test load of 275 15 ml of water at an initial temperature 20 5 C 3 5 0mW cm without a test load B 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 CSA and NHW performance standard for microwave ovens must be used for testing recommended instruments are NARDA 8100 and NARDA 8200 2 Place the oven tray in the oven cavity 3 Place the load of 275 15 ml of tap water initially at 20 5 C in the center of the oven cavity The water container shall be a low form of 600 ml 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 Set the cooking control on Full Power Cooking Mode Close the door 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 4 C Leakage test with enclosure installed 1
77. ost cases the food cooking results will be satisfactory Difference in power supply voltage will also affect the oven temperature The Household power supply voltage may sometimes become lower than the rated voltage 117 V and cause under cooking If the power supply voltage is 10 lower than the rated voltage longer cooking time is required by 10 to 20 NOISE FILTER TEST Disconnect the oven from power supply Disconnect the lead wires from the terminal the noise filter Using an ohmmeter check between the terminals as described in the following table MEASURING POINT INDICATION OF OHMMETER MN NOISE FILTER NOISE SUPPRESSION COIL FUSE 20A On LINE CROSS CAPACITOR 0 22 AC 250V Between N and Open circuit Between terminal N and GRAY Short circuit Between terminal H and RED Short circuit If incorrect reading are obtained replace the noise filter TOUCH CONTROL PANEL ASSEMBLY TEST LINE BYPASS 0 00 125V CAPACITOR LINE BYPASS CAPACITOR 0 0033uF 125V GRY RED The touch control panel consists of circuits including semiconductors such as LSI ICs etc Therefore unlike conventional microwave ovens proper maintenance cannot be performed with only a voltmeter and ohmmeter In this service manual the touch control panel assembly is divided into two units Cont
78. 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 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 HI 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 22 to 43 F 12 2 to 23 8 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
79. ower approx 70 of Full Power approx 60 of Full Power 50 of Full Power approx 40 of Full Power approx 30 of Full Power approx 20 of Full Power approx 10 of Full Power No power throughout the cooking time Convection Temperature for Variable Cooking CONVECTION 100 450 F Temp control LOW MIX BAKE 350 F with 10 microwave power HIGH MIX ROAST 300 F with 30 microwave power SLOW COOK 300 F for 4 hours no preheat 450 F preheat Help pad Reheat pad Add A Minute pad Popcorn pad Defrost pad Sensor Cook pad Convec Broil pad Convec Roast pad Convec Bake pad Convec pad Broil pad Slow Cook pad Preheat pad Number and temperature selection pads Timer pad Clock pad Stop Clear pad Power Level pad Start Touch On pad Oven Cavity Light Yes Safety Standard UL Listed FCC Authorized DHHS Rules CFR Title 21 Chapter 1 Subchapter J Canadian Standards Association Health CANADA Industry CANADA GENERAL INFORMATION 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 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 6 Electrical Requirements The electrical requirements are a 115 120 volt 60 Hz AC only
80. peration of the relay RY1 and the primary interlock switch and is mechanically associated with the door so that it will function in the following sequence 1 When the door opens from a closed position the door sensing switch and the primary interlock switch open their contacts and then the monitor switch contacts close and then the third door switch contacts open 2 When the door is closed from the open position the monitor switch contacts open and the third door switch contacts close first and then the contacts of the primary interlock switch and the door sensing switch close If the relay and the primary interlock switch fail with their contacts closed when the door is opened the closing of the monitor switch contacts will form a short circuit through the monitor fuse the relay RY1 and the primary interlock switch causing the monitor fuse to blow POWER LEVEL P 0 TO P 90 COOKING When Variable Cooking Power is programmed the 117 volts A C is suppliedto the power transformer intermittently through the contacts of relay RY 2 RY 2 is operated by the control unit within an varying time base Microwave power operation is as follows VARI MODE ON TIME OFF TIME Power 10 32 sec 0 sec 10096 power Power 9 P 90 30 sec 2 sec approx 9096 power Power 8 P 80 26 sec 6 sec approx 8096 power Power 7 P 70 24 sec 8 sec approx 7096 power Power 6 P 60 22 sec 1
81. rol Unit and Key Unit and troubleshooting by unit replacement is described according to the symptoms indicated 1 Key Unit Note Check key unit ribbon connection before replacement The following symptoms indicate a defective key unit Replace the key 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 2 Control Unit The following symptoms indicate a defective control unit Replace the control unit 2 1 In connection with pads a When touching the pads a certain group of pads do not produce a signal b When touching the pads no pads produce a signal 2 2 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 All digits in the figure flicker 2 3 Other possible troubles caused by defective control unit a Buzzer does not sound or continues to sound b Clock does not operate properly c Cooking is not possible d Proper temperature measurement is not obtained Note When defective components the Control Unit or Key Unit are replaced the defective part or parts must be properly packe
82. seconds after the thermistor is energized the voltage across the temperature measurement circuit is sampled by the LSI and twenty one 21 seconds after the thermistor is cut off the LSI turns on the cooling fan for six 6 seconds 2 The above procedure is repeated If the difference between the first voltage measured in step 1 and the voltage measured when the procedure is repeated step 2 is greater than 300mV the LSI makes the judgment that there is a fire in the oven cavity and will switch off the relays to the power transformer fan motor and convection motor The LSI also stops counting down and closes the damper door so that no fresh air will enter the oven cavity Once the fire sensor feature has shut the unit down the programmed cooking cycle may be resumed by pressing the START pad or the unit may be reset by pressing the CLEAR pad 30 32 sec 64 l CONVECTION MOTOR 1 1 Sensing Voltage OFF i Sensing the voltage across temperature measurement circuit DMOC205SS VMOC205SS IMPORTANT detected vapors and initiated a sensor cooking cycle During sensor cooking operation the fire sensing op This is because the operation of the convection fan eration sequence will not begin untilthe AH sensor has would interfere with the AH sensor s vapor detection SCHEMATIC DIAGRAM SCHEMATIC NOTE CONDITION OF OVEN 1 DOOR CLOSED 2 CLOCK APPEARS ON DISPLAY
83. strobe signal Signal applied to touch key section A pulse signal is input to P24 P27 terminal while one of G 7 line keys on key matrix is touched Segment data signal Signal similar to P23 Key strobe signal Signal applied to touch key section A pulse signal is input to P24 P27 terminal while one of G 6 line keys on key matrix is touched Segment data signal Signal similar to P23 Key strobe signal Signal applied to touch key section A pulse signal is input to P24 P27 terminal while one of G 5 line keys on key matrix is touched P07 P03 Segment data signal Signal similar to P23 P02 P00 Digit selection signal Signal similar to P55 P37 P35 Digit selection signal Signal similar to P55 P34 P30 Used for initial balancing of the bridge circuit absolute humidity sensor DMOC205SS VMOC205SS ABSOLUTE HUMIDITY SENSOR CIRCUIT 1 Structure of Absolute Humidity Sensor The absolute 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 metal mesh to be protected from the external airflow Sensing part sensing part Open vessel Close Sensing part vessel Open vessel Sensing part Closed vessel AIL Thermistor element Sensor case
84. switch do not operate properly opened due to a misadjustment the following adjustment should be made 1 Loosen the two 2 screws holding latch hook to the oven cavity front flange 2 With door closed adjust latch hook by moving it back Z and forth and up and down In and out play of the door allowed by the latch hook should be less than 0 5mm pd The vertical position of the latch hook should be adjusted so that the door sensing switch and primary interlock switch are activated with the door closed The horizontal Henne position of the latch hook should be adjusted so that the plungers of the monitor switch and the third door switch are pressed with the door closed 3 Secure the screws with washers firmly 4 Check the all switches operation If each switch has not activated with the door closed loosen the screw and adjust it DOOR OPEN BUTTON 7 LATCH HOOK THIRD DOOR SWITCH DOOR SENSING SWITCH MONITOR SWITCH PRIMARY INTERLOCK SWITCH SWITCH LEVER OPEN LEVER After adjustment check the following 1 In and out play of door remains less than 0 5mm at the 5 Re install outer case and check for microwave leakage around door with an approved microwave survey meter Refer to Microwave Measurement Procedure DOOR REPLACEMENT AND ADJUSTMENT Figure C 4 Latch Switch Adjustments REMOVAL 4 Remove door assembly from upper oven hinge on the 1 Disconnect oven from power supply and remove t
85. ted to the heating element and power transformer 6 2 The heating element operates through the heater relay RY3 contacts and the power transformer operates through the primary interlock relay RY2 contacts 6 3 These are operated by the control unit to supply alternately within a 32 second time base convection heat and microwave energy The relationship between the convection and microwave power operations are as follows Note The ON and OFF time ratio does not correspond with the percentage of microwave power because approx 2 seconds are needed for heating of the magnetron filament 16 SEC 26 SEC OFF 7 ZT LOW MIX BAKE MICROWAVE POWER APPROX 10 MICRO CONVECTION TEMPERATUE 350 F 180 C 20 SEC 12 SEC ON MICROWAVE POWER MICRO OFF APPROX 30 ON CONVEC CONVECTION TEMPERATUE 300 F OFF 2 32 SEC HIGH MIX ROAST During alternate Microwave Convection operation the convection heater is energized only if the cavity temperature drops below the set temperature SENSOR COOKING CONDITION Using the SENSOR COOK function the foods are cooked without figuring 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
86. the hot air circulates inside the oven cavity to raise its temperature and at the same time comes into contact with the food being cooked When the temperature inside the oven cavity reaches the selectedtemperature the heating elementis de energized When the temperature inside the oven cavity drops below the selected temperature the heating element is energized again In this way the inside of the oven cavity is maintained at approximately the selected temperature When the convection time reaches 0 the heating element is de energized and the convection fan stops operating and the oven shuts off DAMPER OPEN CLOSE MECHANISM Usually the damper is in the open position except during convection cooking Damper position is set automatically by damper motor damper switch motor cam and damper shaft These components are operated by a signal that judges if microwave cooking or convection cooking opera tion is selected by the control unit Microwave Cooking Damperis in the open position because a portion of cooling air is channelled through the cavity to remove steam and vapors given off from the heating foods It is then exhausted at the top of the oven cavity into a condensation compartment Convection Cooking Damper is in the closed position so that no hot air will be allowed to leak out the oven cavity Damper Operation 1 When power supply cord is plugged in 1 1 When power supply cord is plugged in a signal is sensed
87. tor CN A CN E and CN F from the control unit Disconnect the wire leads from the relays RY1 RY2 and RY3 Remove one 1 screw holding the control panel back plate to the chassis support Remove two 2 screws holding the bottom edge of the back plate to the cabinet base Remove one 1 screw holding the back plate to the oven 2 3 32 cavity flange 8 Lift up and pull the control panel assembly forward Replacement of individual component is as follows CONTROL UNIT AND KEY UNIT 1 Disconnect the wire connector from the control unit 2 Remove the four 4 screws holding the panel frame to the back plate Separate the panel frame and back plate Remove the three 3 screws holding the control unit to the panel frame Liftup the control unit and disconnect the key connector from the control unit 3 4 DMOC205SS VMOC205SS panel frame adjust the lower edge and right edge ofthe key unitto the correct position of the control panel frame 3 Stick the key unit firmly to the control panel frame by rubbing with soft cloth not to scratch 6 Now the control unit and frame assembly are separated NOTE 1 Before attaching a new key unit remove remaining adhesive on the control panel frame surfaces completely with alcohol and so on 2 When a attaching the key unit to the control THIRD DOOR SWITCH DOOR SENSING SWITCH PRIMARY INTERLOCK SWITCH AND MONITOR SWITCH REMOVAL of switches place 8 Switch is no
88. tor Circuit Indicator element is a Fluorescent Display Basically a Fluorescent Display is triode having a cathode a grid and an anode Usually the cathode of a Fluorescent Display is directly heated and the filament serves as cathode The Fluorescent Display has 8 digits 16 segments are used for displaying figures DESCRIPTION OF LSI LSI IXA103DR The I O signals of the LSI IXA103DR are detailed in the following table a Connected to GND Anode segment of Fluorescent Display light up voltage 30V Vp voltage of power source circuit input Power source voltage 5V VC voltage of power source circuit input Reference voltage input terminal A reference voltage applied to the A D converter in the LSI Connected to GND OV DMOC205SS VMOC205SS Pin No Signal Wo 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 AH sensor input This input is an analog input terminal from the AH sensor circuit and connected to the A D converter built into the LSI 5 Heating constant compensation terminal Input signal which communicates the door open close information to LSI Door closed H level signal 0V Door opened L level signal 5V Input signal which communicates the damper open close information to LSI Da
89. unding wire to the air guide Right with one 1 screw L Shaft M Table 7777777777 Center of bracket POWER SUPPLY CORD REPLACEMENT Coi P Groove joint pliers Stator Shaft xil Gap Axis Xd 4 with pliers Bracket Rotor sir Rotor Rear View Side View Removal 1 Disconnect oven from power supply and remove outer case 2 3 Discharge high voltage capacitor Disconnect the white and black wires of the power supply cord from the noise filter Remove the one 1 screw holding the earth wire of the power supply cord to the base cabinet 5 Remove the power supply cord from the rear cabinet Re install 1 Insert the power supply cord into the rear cabinet 2 Connect the white and black wires of the power supply cord into the terminal of noise filter referring to the Pictorial Diagram Re install the earth wire of the power supply cord to the base cabinet with the one 1 screw 4 9 Noise filter GRY RED Power White wire supply cord Rear Cabinet Green wire Base Cabinet Figure C 3 Power supply cord replacement CONTROL PANEL ASSEMBLY AND CONTROL UNIT REMOVAL To remove the control panel procedure as follows 1 Disconnect oven from power supply and remove outer case Discharge high voltage capacitor Disconnect connec
90. urement signal AH sensor signal key strobe signal relay driving signal for oven function and indicator signal 2 Power Source Circuit This circuit generates the voltages necessary for the control unit from the AC line voltage 3 Synchronizing Signal Circuit The power source synchronizing signal is available in order to compose a basic standard time in the clock circuit It incorporates a very small error because it works on commercial frequency ACL Circuit A circuit to generate a signals which resetting the LSI to the initial state when power is applied 4 5 Buzzer Circuit The buzzer is responds to signals from the LSI to emit noticing sounds key touch sound and completion sound 6 w Temperature Measurement Circuit THERMISTOR The temperature in the oven cavity is sensed by the thermistor The variation of resistance according to sensed temperature is detected by the temperature measurement circuit and the result applied to LSI The LSI uses this information to control the relay and display units OVEN 7 Absolute Humidity Sensor Circuit This circuit detects the humidity of a food which is being cooked to control its automatic cooking 8 Door Sensing Switch A switch to inform the LSI if the door is open or closed 9 Relay Circuit To drive the magnetron heating element fan motor convection motor damper motor turntable motor and light the oven lamp 10 Indica
91. w free 1 Disconnect oven from power supply and remove outer At this time switch lever will be free do not lose it case Re install 2 Discharge high voltage capacitor 1 Re install switch lever and each interlock switch in its 3 Remove the control panel assembly refer to Control place The primary interlock switch is in the lower Panel Removal position and the door sensing switch and thir door switch 4 Disconnect wire leads from each of the switches and are in the upper position and the monitor switch is in the fuse holder middle position 5 Remove two 2 screws holding latch hook to oven 2 Re connect wire leads to each switches and fuse holder flange Refer to pictorial diagram 6 Remove latch hook assembly from oven flange 3 Secure latch hook with two 2 mounting screws to 7 Push outward on the one 1 stopper tabs holding each oven flange 4 Make sure that the monitor switch is operating properly and check continuity of the monitor circuit Refer to chapter Test Procedure and Adjustment procedure THIRD DOOR SWITCH DOOR SENSING SWITCH PRIMARY latched position INTERLOCK SWITCH AND MONITOR SWITCH 2 The door sensing switch and primary interlock switch ADJUSTMENT interrupt the circuit before the door can be opened 3 Monitor switch contacts close when door is opened If the door sensing switch third door switch primary 4 The third door switch contacts open when the door is interlock switch and monitor
92. y 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 NOTE After servicing record data on service invoice and microwave leakage report SERVICE MANUAL VIKING RANGE CORPORATION MICROWAVE OVENS DMOC205SS VMOC205SS FOREWORD This Manual has been prepared to provide Viking Service Personnel with Operation and Service Information for the Viking Microwave Ovens DMOC205SS VMOC205SS It is recommended that service personnel carefully study the entire text of this manual so that they will be qualified to render satisfactory customer service Check the interlock switches and the door seal carefully Special attention should be given to avoid electrical shock and microwave radiation hazard 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 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 Donotcontactthefollowing parts whilethe appliance is energized

Viking DMOC205SS User's Manual

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