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6. DISASSEMBLY AND ASSEMBLY

- Cautions to be observed when trouble shooting.

Unlike many other appliances, the microwave oven is high-voltage, high-current equipment. It is completely safe
during normal operation. However, carelessness in servicing the oven can result in an electric shock or possible
danger from a short circuit. You are asked to observe the following precautions carefully.

1. Always remove the power plug from the outlet before servicing.
2. Use an insulated screwdriver and wear rubber gloves when servicing the high voltage side.
3. Discharge the high voltage capacitor before touching any oven components or wiring.

(1) Check the grounding.

Do not operate on a two-wire extension cord.
The microwave oven is designed to be used while grounded.
It is imperative, therefore, to make sure it is grounded 
properly before beginning repair work.

(2) Warning about the electric charge in the high voltage capacitor.  

For about 30 seconds after the operation has stopped, electric
charge remains in the high voltage capacitor. 
When replacing or checking parts, short between oven chassis
and the negative high terminal of the high voltage capacitor by
using a properly insulated screwdriver to discharge.

4. When the 15A fuse is blown out due to the operation of the monitor

switch; replace primary interlock switch, secondary interlock switch
and interlock monitor switch.

5. After repair or replacement of parts, make sure that the screws are 

properly tightened, and all electrical connections are tightened.

6. Do not operate without cabinet.

CAUTION  : Service personnel should remove their watches whenever working close to or replacing the magnetron.

WARNING : When servicing the appliance, take care when touching or replacing high potential parts because of

electrical shock or exposing microwave. These parts are as follows - HV Transformer, Magnetron,
HV Capacitor, HV Diode.

SHORT

Summary of Contents for KOC-621Q0S

Page 1: ...Service Manual Microwave Oven Model KOC 621Q0S S M NO C621Q0S001 DAEWOO ELECTRONICS CO LTD http svc dwe co kr Dec 2001...

Page 2: ...usted 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 r...

Page 3: ...certified oven unit is found to servicing a microwave emission check should be performed prior to servicing the oven 1 inform the manufacturer importer or assembler 2 repair the unit at no cost to th...

Page 4: ...IEC705 MICROWAVE FREQUENCY 2450MHz OUTSIDE DIMENSIONS W X H X D 470X285X376mm 18 5X11 2X14 8 in CAVITY DIMENSIONS W X H X D 295X167X300mm 11 6X6 6X11 8 in NET WEIGHT APPROX 15kg 33 1 lbs TIMER Oven 9...

Page 5: ...t the microwave 13 TOP HEATER Turns on when convection grill and combi cooking is selected 14 OVEN LAMP Automatically turns on during oven operating 15 SAFETY INTERLOCK SYSTEM 16 CONTROL PANEL 17 UNDE...

Page 6: ...aged must be repaired with cable of same type Such a cable can be purchased from DAEWOO and must be installed by a Qualified Person 6 Examine the oven after unpacking for any damage such as A misalign...

Page 7: ...ost Press to select weight time defrost mode 3 grill Press to select grill 4 combi Press to select combi cooking mode 5 temp Press to select temperature 6 10m Press to set time and weight 7 1m Press t...

Page 8: ...g repair work 2 Warning about the electric charge in the high voltage capacitor For about 30 seconds after the operation has stopped electric charge remains in the high voltage capacitor When replacin...

Page 9: ...top 2 Remove the door assembly from top plate of cavity 3 Reverse the above for assemby 3 To remove door parts REF NO PART CODE PART NAME DESCRIPTION Q TY REMARK A01 3512203410 FRAME DOOR ABS 1 A02 3...

Page 10: ...rt A Loosen two screws on stopper hinge top and then push the door to contact the door seal to oven front surface Tighten two screws 2 To reduce gap located on part B Loosen two screws on stopper hing...

Page 11: ...23500 SWITCH MEMBRANE KOC 621Q0S 1 B02 3516715810 CONTROL PANEL ABS 1 B03 3514325720 PCB AS KOC 621Q0S 1 B04 7112401211 SCREW TAPPING T1 TRS 4X12 MFZN 4 1 Remove four screws B04 which secure the PCB A...

Page 12: ...door normally closed Magnetron antenna Metallic gasket plate Cooling fin Filament terminal 6 To remove high voltage capacitor 1 Remove a screw which secure the grounding ring terminal of the H V diod...

Page 13: ...assembly 4 Draw forward the wind guide assembly 5 Pull the fan from the motor shaft 6 Remove two screws which secure the motor shaded pole 7 Remove the motor shaded pole 8 Reverse the above steps for...

Page 14: ...5 3 Pull out heater 4 Reverse the above steps for reassembly REF NO PART CODE PART NAME DESCRIPTION Q TY REMARK 1 7112401011 SCREW TAPPING T1 TRS 4 10 MFZN 2 2 3511409700 COVER INSU T AS KOC 621Q0S 1...

Page 15: ...ssembly 4 Remove a screw2 5 Pull out the Heater U 3 from the Cover heater U 5 6 Reverse the above steps for reassembly REF NO PART CODE PART NAME DESCRIPTION Q TY REMARK 1 7122400811 SCREW TAPPING T2S...

Page 16: ...closed the hook pushes the lock lever downward The lock lever presses the button of the interlock monitor switch to bring it under OFF condition and presses the button of the secondary interlock switc...

Page 17: ...n of the terminals and power cord before check the parts listed below CONDITION CHECK Check continuity of interlock monitor switch with door closed COM NC Check continuity of both primary and secondar...

Page 18: ...ment for adjustment instructions TROUBLE 2 Display shows all figures selected but oven does not start cooking even though desired program and time are set and start button is tapped CONDITION CHECK Ch...

Page 19: ...ds to magnetron terminal and magnetron body Continuity Defective magnetron 2 1 Check resistance of primary and secondary coil of high voltage transformer 0 or Defective high voltage transformer Replac...

Page 20: ...Adjust or replace Defective touch control circuit 0V Approx 13V DC Replace Check continuity of heater Defective heater No continuity Replace TROUBLE 5 Fan motor does no rotate CONDITION CHECK Check co...

Page 21: ...for continuity of the pad Malfunction of Membrane RESULT Normal CAUSE REMEDY Replace C PANEL assembly Display does not show programming at all even if keyboard is touched TROUBLE 7 The following visua...

Page 22: ...inuity of thermistor resistance of thermistor Defective thermistor RESULT 0 or infinite Replace Err 2 or Err 3 come on display Check continuity of heater upper lower Defective touch control circuit Re...

Page 23: ...in the lowest normal position 4 Microwave power is switched on 5 Heating time should be exactly A seconds Refer to table as following Heating time is measured while the microwave generator is operatin...

Page 24: ...in a counter clockwise direction at a rate of 1 in sec If the leakage of the cabinet door seem is unknown move the probe more slowly 4 When measuring near a corner of the door keep the probe perpendi...

Page 25: ...ter set on the highest resistance scale measure the resistance across the diode terminals Reverse the meter leads and again observe the resistance reading Meter with 6V 9V or higher voltage batteries...

Page 26: ...25 4 COMPONENT ACTION COOKING MODE MANUAL M W MODE GRILL COMBI TEMP DEFROST AUTO ROAST BEEF COOK ROAST PORK ROAST CHICKEN FISH FILLETS VEGETABLE MAGNETRON UPPER ELEMENT LOWER ELEMENT...

Page 27: ...26 10 WIRING DIAGRAM...

Page 28: ...27 11 EXPLODED VIEW AND PARTS LIST 1 DOOR ASSEMBLY Refer to 6 Disassembly and assembly 2 CONTROL PANEL ASSEMBLY Refer to 6 Disassembly and assembly 3 TOTAL ASSEMBLY...

Page 29: ...302200 1 F28 DIODE HV HVR 1X 3AB 12KV 187 3518400400 1 F29 FUSE HV 5KV 0 7A HV 41A70 1 187 3518700230 1 F30 TRANS HV DW R80S0 62T 3518118710 1 F31 SPECIAL SCREW TT3 HEX 4X8 FLG MFZN 3516003700 4 F32 B...

Page 30: ...on to fluctuation of power source voltage 2 The allowable tolerance of the secondary voltage is within 5 of nominal voltage NOTE Each measure point must be measured with GND points Terminal 6 10 Volta...

Page 31: ...1 does not operate 3 When touching M W button oven lamp turn on and turns on and fan motor does not rotate but cook indicator in display comes on Cause RELAY 6 does not operate STATE RELAY 1 ON RELAY...

Page 32: ...ting of lower grill When touching TEMP button oven lamp turns on and Fan motor and turntable rotate and cook indicator in display comes on Cause RELAY 4 does not operate STATE RELAY 3 ON RELAY 3 OFF P...

Page 33: ...ount down timer does not stop POINT STATE DOOR OPEN DOOR CLOSED A OPEN CLOSE B 5V DC GND A B CN1 D O M SW 1 2 35313 0210 D1 1N4148 R1 1K 5V R4 10K C1 104Z 7 CHECK NO METHOD REMEDY 1 Check the stage ON...

Page 34: ...33 13 P C B CIRCUIT DIAGRAM...

Page 35: ...D AZ103J 4 21 RESISTOR R1 R32 R34 1 6W 1K Ohm 5 RD AZ102J 3 22 RESISTOR R40 1 6W 2K Ohm 5 RD AZ202J 1 23 RESISTOR R38 R39 1 6W 4 7K Ohm 5 RD AZ472J 2 24 RESISTOR R5 R9 R17 R18 1 6W 100K Ohm 5 RD AZ104...

Page 36: ...S M NO C621Q0S001 DAEWOO ELECTRONICS CO LTD 686 AHYEON DONG MAPO GU SEOUL KOREA C P O BOX 8003 SEOUL KOREA TELEX DWELEC K28177 8 CABLE DAEWOOELEC http www daewoo co kr PRINTED DATE DEC 2001...

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