MICROWAVE OVEN MD800WC (WHITE) MD800SC (SILVER) SERVICE MICROWAVE OVEN Manual CONTENTS 1. Precaution .......................................... 1 2. Specifications .................................... 3 3. Operating Instructions....................... 4 4. Disassembly and Reassembly ....... 5 5. Alignment and Adjustment ............. 9 6. Troubleshooting ............................... 13 7. Exploded Views and Parts List .... 15 8. PCB Diagrams ................................. 19 9. Schematic Diagrams .
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 surfaces (arcing, wear, and other damage), (4) damage to or loosening of hinges and latches.
1. Precaution Follow these special safety precautions. Although the microwave oven is completely safe during ordinary use, repair work can be extremely hazardous due to possible exposure to microwave radiation, as well as potentially lethal high voltages and currents. 1-1 Safety precautions ( ) 11. To avoid any possible radiation hazard, replace parts in accordance with the wiring diagram.
1-2 Special Servicing Precautions (Continued) 17. When checking the continuity of the switches or transformer, always make sure that the power is OFF, and one of the lead wires is disconnected. 18. Components that are critical for safety are indicated in the circuit diagram by shading, or . 19. Use replacement components that have the same ratings, especially for flame resistance and dielectric strength specifications.
2. Specifications 2-1 Table of Specifications TIMER 99 MINUTES 99SECONDS POWER SOURCE 120V 60Hz, AC POWER CONSUMPTION MICROWAVE : 1,150W OUTPUT POWER FROM 80 TO 800W ( 10 LEVEL POWER ) (ICE-705 TEST PROCEDURE) OPERATING FREQUENCY 2,450MHz MAGNETRON OM75S(20) COOLING METHOD COOLING FAN MOTOR OUTSIDE DIMENSIONS 16"(W) x 12 37/64"(H) x 17 NET WEIGHT 30.2 lbs. SHIPPING WEIGHT 33.3 lbs.
3. Operating Instructions 3-1 Control Panel 319.5 mm 3-2 Features & External Views 215 mm 305 mm 406.
4. Disassembly and Reassembly 4-1 Replacement of Magnetron, Motor Assembly and Lamp Remove the magnetron including the shield case, permanent magnet, choke coils and capacitors (all of which are contained in one assembly). 1. 2. 3. 4. Disconnect all lead wires from the magnetron. Remove a screw securing air cover. Remove the air cover. Remove screws securing the magnetron to the wave guide. 5. Take out the magnetron very carefully. 6. Remove a screw securing Bracket MGT. 7. Remove the Bracket MGT.
4-3 Replacement of Control Circuit Board 4-3-1 Removal of Control Box Assembly SCREW 1. Remove the screws securing the out panel and take out the out panel. 2. Disconnect all lead wires from the control box. 3. Remove screws securing the rear of the control box. SCREW Control-box 4. Push the control box to left side then take out the control box. 4-3-2 Removal of Main P.C.B Assembly 1. Disconnect all lead wires from the Main P.C.B. 2. Remove screws securing and plastic fasteners of the Main P.C.B.
4-4 Replacement of Fuse 1. Disconnect the oven from the power source. 2. When 15A fuse blows out by the operation of interlock monitor switch failure, replace the primary interlock switch, door sensing switch, monitor switch and power relay. 3. When the above three switches operate properly, check if any other part such as the control circuit board, blower motor or high voltage transformer is defective. 4-5 Replacement of Drive Motor 1. Take out the glass tray, guide roller from cavity. 2.
4-6-2 Removal of Door "E" 1. Following the procedure as shown in the figure, insert and bend a thin metal plate between Door "E" and Door "A" until you hear the 'tick' sound. Door "E" 2. Insertion depth of the thin metal plate should be 0.5mm or less. 4-6-3 Removal of Screen Door and Door A 1. Remove a screw securing Door A and Screen Door. 4-6-4 Removal of Key Door & Spring 1. Push up key door, take out key door from Door "E" Door "E" slot. 2. Take out spring.
5. Alignment and Adjustments PRECAUTION 1. High voltage is present at the high voltage terminals during any cook cycle. 2. It is neither necessary nor advisable to attempt measurement of the high voltage. 3. Before touching any oven components or wiring, always unplug the oven from its power source and discharge the high voltage capacitor. 5-1 High Voltage Transformer 1. Remove connectors from the transformer terminals and check continuity. 2.
5-4 High Voltage Capacitor 1. 2. 3. 4. 5. Check continuity of the capacitor with the meter set at the highest resistance scale. Once the capacitor is charged, a normal capacitor shows continuity for a short time, and then indicates 9MΩ. A shorted capacitor will show continuous continuity. An open capacitor will show constant 9MΩ. Resistance between each terminal and chassis should read infinite. 5-5 High Voltage Diode 1. Isolate the diode from the circuit by disconnecting its leads. 2.
5-8 Output Power of Magnetron CAUTION MICROWAVE RADIATION PERSONNEL SHOULD NOT ALLOW EXPOSURE TO MICROWAVE RADIATION FROM MICROWAVE GENERATOR OR OTHER PARTS CONDUCTING MICROWAVE ENERGY. The output power of the magnetron can be measured by performing a water temperature rise test. Equipment needed : * Two 1-liter cylindrical borosilicate glass vessel (Outside diameter 190 mm) * One glass thermometer with mercury column NOTE: Check line voltage under load. Low voltage will lower the magnetron output.
5-10 Procedure for Measurement of Microwave Energy Leakage 1. Pour 275±15cc of 20±5°C(68±9°F) water in a beaker which is graduated to 600cc, and place the beaker in the center of the oven. 2. Start to operate the oven and measure the leakage by using a microwave energy survey meter. 3. Set survey meter with dual ranges to 2,450MHz. 4. When measuring the leakage, always use the 2 inch spacer cone with the probe. Hold the probe perpendicular to the cabinet door.
6. Troubleshooting PRECAUTION 1. 2. 3. 4. CHECK GROUNDING BEFORE CHECKING FOR TROUBLE. BE CAREFUL OF THE HIGH VOLTAGE CIRCUIT. DISCHARGE THE HIGH VOLTAGE CAPACITOR. WHEN CHECKING THE CONTINUITY OF THE SWITCHES OR TRANSFORMER, DISCONNECT ONE LEAD WIRE FROM THESE PARTS AND THEN CHECK CONTINUITY WITHOUT THE POWER SOURCE ON. TO DO OTHERWISE MAY RESULT IN A FALSE READING OR DAMAGE TO YOUR METER. 5. DO NOT TOUCH ANY PART OF THE CIRCUIT OR THE CONTROL CIRCUIT BOARD, SINCE STATIC DISCHARGE MAY DAMAGE IT.
6-1 Electrical Malfunction(continued) SYMPTOM CAUSE Oven lamp and fan motor turn on 1. Misadjustment or loose wiring of secondary latch switch 2. Defective Secondary latch switch Oven can program but timer does not start. 1. Open or loose wiring of secondary interlock switch 2. Off-alignment of Secondary interlock 3. Defective secondary interlock S/W Microwave output is low;. Oven takes longer time to cook food. 1. Decrease in power source voltage. 2.
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7-2 Main Parts List No. Code No. Description B001 3405-001034 SWITCH-MICRO B002 3405-001033 SWITCH-MICRO B006 DE66-00132A B010 DE66-00093A B011 B018 C003 RAS-K2LED-01 C080 DE61-00522A C081 Specification Q'ty Remark 125/250VAC,16A,200GF,SPST-N 2 LATCH(UPPER/LOWER) 125/250VAC,16A,200GF,SPST-N 1 LATCH(MIDDLE) LATCH-BODY MW8ROWC,POM,T2.
7-3 Control and Door Parts List No. Code No.
7-4 Standard Parts List Code No. Description Specification Q'ty Remark DE60-30015A NUT-FLANGE M5,P0.
8. P.C.B Diagrams 8-1 P.C.
8-2 P.C.B Parts List Q'ty Remark 3501-001155 Code No. RELAY-MINIATURE Description 24VDC,200MW,3000MA,1FORMA,10MS,10MS Specification 2 RY01,RY03 3501-001188 RELAY-POWER 24V DC,0.53W,-,1FORMA,9.3MS,10MS 1 RY02 3708-000528 CONNECTOR-FPC/FFC/PIC 13P,2.54mm,STRAIGHT,SN 1 DSP1 3708-001553 CONNECTOR-FPC/FFC/PIC 10P,1.25mm,STRAIGHT,SN 1 CN01 DE09-00051A IC MICOM S3P7054DZZ-SOT4,OTP,SOP,4BIT-32PIN,-,-,-,-,-,-,- 1 IC01 DE26-00037A TRANS L.
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ELECTRONICS This Service Manual is a property of Samsung Electronics Co.,Ltd. Any unauthorized use of Manual can be punished under applicable International and/or domestic law ©Samsung Electronics Co., Ltd. May 2003 Printed in Korea Code No.
