DMOC205SS VMOC205SS SERVICE MANUAL S14M227DMO205 MICROWAVE OVEN MODELS 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.
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.
DMOC205SS VMOC205SS Notes 1
DMOC205SS VMOC205SS WARNING TO SERVICE PERSONNEL Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts may result in a severe, possibly fatal, electrical shock. (Example) High Voltage Capacitor, High Voltage Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc.. Read the Service Manual carefully and follow all instructions. Don't Touch ! Danger High Voltage outer case. 2. Open the door and block it open. 3.
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 meet the requirement of the performance standard for microwave ovens as undermentioned. A.
DMOC205SS VMOC205SS MICROWAVE MEASUREMENT PROCEDURE (USA) A. Requirements: 1) Microwave leakage limit (Power density limit): The power density of microwave radiation emitted by a microwave oven should not exceed 1mW/cm2 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/cm2 at any point 5cm or more from the external surface of the oven.
DMOC205SS VMOC205SS SERVICE MANUAL VIKING RANGE CORPORATION PRODUCT DESCRIPTION MICROWAVE OVENS DMOC205SS VMOC205SS GENERAL INFORMATION 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.
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.
DMOC205SS VMOC205SS Electrical Requirements The electrical requirements are a 115 -120 volt 60 Hz, AC only, 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.
DMOC205SS VMOC205SS OPERATION DESCRIPTION OF OPERATING SEQUENCE 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.
DMOC205SS VMOC205SS first. And then program desired cooking time by touching the Number pads. The LOW MIX/BAKE pad is preprogrammed for 350οF with 10% microwave power, while the HIGH MIX/ROAST pad is preprogrammed for 300οF with 30% microwave power. 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.
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 experiment with each food category and inputted into the LSI. An example of how sensor works: 4. Now, the oven is in the convection cooking mode. 5.
DMOC205SS VMOC205SS IMPORTANT: During sensor cooking operation, the fire sensing operation sequence will not begin until the AH sensor has detected vapors and initiated a sensor cooking cycle. This is because the operation of the convection fan would interfere with the AH sensor's vapor detection. SCHEMATIC DIAGRAM SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR CLOSED. 2. CLOCK APPEARS ON DISPLAY. RY2 A-9 RY3 CONTROL UNIT E-1 E-2 E-3 SECONDARY INTERLOCK RERAY F-3 E-4 E-5 E-6 F-2 F-1 COM. (RY2) N.O.
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. RY2 A-9 RY3 CONTROL UNIT E-1 E-2 E-3 SECONDARY INTERLOCK RERAY F-3 E-4 E-5 E-6 F-2 F-1 COM. (RY2) N.O. (RY2) N.O. (RY3) 117V 60Hz DOOR SENSING SWITCH THIRD DOOR SWITCH THERMISTOR DAMPER SWITCH AH SENSOR CAPACITOR 0.94µ MAGNETRON A-7 POWER TRANSFORMER H.V.
DMOC205SS VMOC205SS DESCRIPTION AND FUNCTION OF COMPONENTS DOOR SENSING AND PRIMARY INTERLOCK SWITCHES 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.
DMOC205SS VMOC205SS 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.
TEST PROCEDURE O PROBLEM POSSIBLE CAUSE AND DEFECTIVE PARTS A MAGNETRON B POWER TRANSFORMER C H.V. RECTIFIER ASSEMBLY D E HIGH VOLTAGE CAPACITOR PRIMARY INTERLOCK SWITCH F SECONDARY INTERLOCK SYSTEM G MONITOR SWITCH H MONITOR FUSE E THIRD DOOR SWITCH I THERMAL CUT-OUT J K CONVECTION HEATER THERMISTOR L DAMPER MOTOR M DAMPER SWITCH P TOUCH CONTROL PANEL Q KEY UNIT R RELAY RY-1 R RELAY RY-2 R RELAY RY-3 R RELAY RY-4 R RELAY RY-5 R RELAY RY-6 T FOIL PATERN ON PWB.
DMOC205SS VMOC205SS TEST PROCEDURES PROCEDURE LETTER A COMPONENT TEST 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.
DMOC205SS VMOC205SS TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST If the 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 MΩ once the capacitor is charged.
DMOC205SS VMOC205SS TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 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 257οF (125οC). 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.
DMOC205SS VMOC205SS TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 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. 30οF more or less than indicated on the display, however, in most cases the food cooking results will be satisfactory.
DMOC205SS VMOC205SS TEST PROCEDURES PROCEDURE LETTER Q COMPONENT TEST 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.
DMOC205SS VMOC205SS TEST PROCEDURES PROCEDURE LETTER T COMPONENT TEST 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.
DMOC205SS VMOC205SS TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 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.
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. 5) Buzzer Circuit The buzzer is responds to signals from the LSI to emit noticing sounds (key touch sound and completion sound). (1) Key Unit (2) Control Unit 6) Temperature Measurement Circuit : (OVEN THERMISTOR) The temperature in the oven cavity is sensed by the thermistor.
DMOC205SS VMOC205SS Pin No. Signal I/O 5 AN7 IN 6 AN6 IN 7-9 10 AN5-AN3 AN2 IN IN 11 AN1 IN 12 AN0 IN 13 P55 OUT Description 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.
DMOC205SS VMOC205SS Pin No. 18 Signal I/O P50 OUT Description Damper motor relay driving signal. To turn on and off shut-off relay(RY4). 19 20-21 22 23 P47 OUT P46-P45 P44 OUT OUT P43 OUT H : GND OFF ON L Heating element driving signal. To turn on and off shut-off relay(RY3). "L" level H. GND During during convection cooking; "H" level otherwise.
DMOC205SS VMOC205SS Pin No. 37 38-40 Signal I/O P23 OUT P22-P20 OUT 41 P17 OUT 42 P16 OUT 43 P15 OUT 44 P14 OUT 45 P13 OUT 46 P12 OUT 47 P11 OUT 48 P10 OUT 49-53 P07-P03 OUT 54-56 P02-P00 OUT 57-59 P37-P35 OUT 60-64 P34-P30 OUT Description Segment data signals. The relation between signals and indicators are as follows: Signal Segment Signal Segment Signal Segment Signal Segment P23 ............. P1 P17 ............. P5 P13 ............. P9 P07 ...........
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.
DMOC205SS VMOC205SS SERVICING 1. 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.
DMOC205SS VMOC205SS COMPONENT 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 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. 3.
DMOC205SS VMOC205SS HIGH VOLTAGE RECTIFIER ASSEMBLY REMOVAL 1. Disconnect oven from power supply and remove outer case. 2. Discharge the high voltage capacitor. 3. Remove one (1) screw holding the rectifier assembly to the capacitor holder. 4. 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 1.
DMOC205SS VMOC205SS HEATER UNIT ASSEMBLY REMOVAL (HEATING ELEMENT/CONVECTION FAN/CONVECTION MOTOR/THERMISTOR) THERMISTOR REMOVAL HEATING ELEMENT 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.
DMOC205SS VMOC205SS 16.Remove the two (2) screws and nuts holding the fan motor to the fan duct. 17.Now, the fan motor is free. * * 3. 4. INSTALLATION 1. Install the fan motor to the fan duct with the two (2) screws and nuts. 2. 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.
DMOC205SS VMOC205SS panel frame, adjust the lower edge and right edge of the key unit to 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.
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".).
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. Leakage test: Leakage Test with Enclosure Installed. 1.
1 2 3 36 4 CN-A RY6 T1 PNK RED BLK ORG BRN RED 5 9 WHT 3 BRN 4 5 PPL 6 7 8 1 ORG 2 CN-A RY1 (N.O.) RY1 (COM.) RY2 (N.O.) RY2 (COM.) RY3 (N.O.) RY3 (COM.) BRN PRIMARY INTERLOCK SWITCH COM BRN RED N.O. COM MONITOR SWITCH PNK GRY G R Y TURNTABLE MOTOR G R Y ORG RED 2 RED RED 1 RED THERMISTOR BRN GRY CONVECTION MOTOR DAMPER MOTOR WHT BLK WHT RED NOISE FILTER AND FUSE H N GRY G R Y G R Y W H T P P L GRN BLK WHT RED PNK CONV.
3 37 A5 FAN MOTOR OVEN LAMP TURNTABLE MOTOR HEATING ELEMENT 4 COM NO COM NO COM POWER TRANSFORMER NO A3 A1 CONV. MOTOR DAMPER MOTOR A7 c RY1 RY3 RY2 RY6 RY5 D2 D3 D23 (J1) C2 1000µ/35v C1 0.1µ/50v + – Q22 KRA101M Q21 KRA101M Q20 KRA101M R3 330 1/2w Q1 2SB1238 5 C11 C3 0.1µ/50v E2 DOOR SWITCH E1 R31 4.7k C30 Q23 KRA101M + – R4 750 1/2w – C50 R8 4.7k Q3 KRA101M E4 OVEN THERMISTOR E3 R62 27kF F1 (A) (C) F3 AH SENSOR F2 (B) CF1 4.
DMOC205SS VMOC205SS 1 2 4 3 5 6 R A A 32 1 DIP ,F B E Q90 1 2 R91 R92 R93 C10 (ONLY PHR) (CF1) CF1 (R85) (C80) (R45) (C45) C7 R7 R8 C8 3 E E 5 B Q4 B Q3 1 12 R79 R78 R77 R76 R75 C 6 C9 (R47) (R48) R64 64 9 C5 (R49) (C46) C6 4 (C47) IC3 1 1 8 C30 C50 C60 13 5 (R46) CN - G IC2 10 11 12 (J7) (J5) (J3) 3 (J2) (J4) (J6) D 14 R40 1 CN - F 15 16 17 CONV HEATER COM 18 BRN E B 1 C3 D31 D30 C4 E Q1 D23 RY2 E E D21 C1 D3 D4 D1 Q22 B D20 F 4 1
DMOC205SS VMOC205SS PARTS LIST •Refer to "IMPORTANT" described at end of parts list. REF. NO. PART NO.
DMOC205SS VMOC205SS REF. NO. 4-16 4-17 4-18 4-19 4-20 4-21 4-22 4-23 4-24 4-25 4-26 4-27 4-28 4-29 4-30 4-31 4-32 4-33 4-34 4-35 4-36 4-37 4-38 4-39 4-40 4-41 4-42 4-43 PART NO.
DMOC205SS VMOC205SS REF. NO. 7-11 7-12 7-13 7-14 7-15 7-16 7-17 7-18 7-19 7-20 7-21 7-22 7-23 7-24 7-25 7-26 7-27 7-28 7-29 PART NO.
4-10 1 2 3 42 4-30 7-24 4-31 1-5 7-21 4-2 4-3 4-9 4-23 TO OVEN BASE PLATE 1-13 7-11 4 5 4-37 1-2 7-4 7-8 x3 7-20 2-11 7-22 7-7 7-4 1-20 4-28 7-5 2-9 7-24 2-10 A 2-4 2-7 x4 4-21 1-2 1-4 1-4 6-7 7-22 x3 7-19 1-1 7-24 1-17 7-24 x4 7-19 2-6 1-4 1-18 x2 4-38 4-14 4-26 6-8 4-27 7-6 4-39 1-9 4-40 1-16 4-17 1-1 4-18 6-7 6-12 7-23 7-10 6-16 7-4 2-5 1-19 7-24 6-13 7-17 7-16 1-6 7-9 4-20 1-14 7-26 7-2 4-19 7-16 4-41 2-2 4-33 A 4
DMOC205SS VMOC205SS 2 1 4 3 6 5 CONTROL PANEL PARTS 3-7 6-11 A A 3-3 3-1 3-6 3-4 3-2 3-9 7-24 B B 3-5 3-7 3-2-1 7-24 3-2-3 C C 3-2-2 5-9 5-2 3-8 D 5-1 D 5-10 5-6 5 5-8 DOOR PARTS E E 5-8 5-8 5-3 VMOC205SS 5-4 5-8 5-7 5-5 DMOC205SS F F 5-11 MISCELLANEOUS G G 6-1 6-4 6-3 6-2 6-10 Actual wire harness may be different than illustration.
DMOC205SS VMOC205SS 2 1 4 3 6 5 PACKING AND TRAYACCESSORIES HOLDER A A TOP PAD ASSEMBLY DOOR PROTECTION SHEET 4-3 TURNTABLE TRAY PLASTIC BAG B B 6-9 OPERATION MANUAL 6-14 S/S CLEANING INSTRUCTIONS 6-15 COOK BOOK MICROWAVE OVEN 4-2 TURNTABLE SUPPORT C C BOTTOM PAD ASSEMBLY TRAY PACKING FOAM D D PACKING CASE Not replaceable items.
DMOC205SS VMOC205SS NOTES: 45
DMOC205SS VMOC205SS 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.
