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18

TROUBLE SHOOTING GUIDE

Following the procedure below to check if the oven is defective or not.

1. Check grounding before trouble checking.
2. Be careful of the high voltage circuit.
3. Discharge the high voltage capacitor.
4. When checking the continuity of the switches, fuse or high voltage transformer, disconnect one lead wire from these parts 
    and check continuity with the AC plug removed. To do otherwise may result in a false reading or damage to your meter.

(TROUBLE 1) 

Door shut, timer set, but no cooking takes place.

Continuity

No Continuity

Continuity

0

 

Or

Approx. 

150~310

(normal)

Replace
NOTE 1

Replace
NOTE 1

Replace

Replace

Check continuity of

primary winding of low

voltage transformer

Malfunction

of interlock

monitor

switch

Defective low

voltage

transformer

Check continuity of

interlock monitor switch

with door closed

(COM C)

Check continuity of primary

interlock switch contact

with door partially open

until interlock monitor switch

contact close

(COM NO )

Shorted contacts

of primary

interlock switch.

Fuse again

blows

Disconnect high voltage

fuse and operate the unit

Defective high

voltage transformer

No Continuity

Replace
NOTE 1

Check continuity of both

primary and secondary

interlock switch with door

closed

Malfunction of
interlock switch

No Continuity

Continuity

  N

CHECK RESULT CAUSE REMEDY

CONDITION

Fuse blows.

      When electric parts are checked, be sure the power cord is not inserted the wall outlet.
     Check wire harness, wiring and connected of the terminals and power cord before check the parts listed below.

NOTE

Summary of Contents for KOR-637V

Page 1: ...Service Manual Microwave Oven AUG 2001 DAEWOO ELECTRONICS CO LTD http svc dwe co kr MODEL KOR 637V S M No R637V0A001 ...

Page 2: ...low the oven to be operated with the door open b Make the following safety checks on all ovens to be serviced before activating the magnetron or other microwave source and make repairs as necessary 1 Interlock operation 2 Proper door closing 3 Seal and sealing surfaces arcing wear and other damage 4 Damage to or loosening of hinges and latches 5 Evidence of dropping or abuse c Before turning on po...

Page 3: ...tified oven unit is found to servicing a microwave emission check should be performed prior to servicing the oven a inform the manufacturer importer or assembler b repair the unit at no cost to the owner c attempt to ascertain the cause of the excessive leakage d tell the owner of the unit not to use the unit until the oven has been brought into compliance 3 If the oven operates with the door open...

Page 4: ...1200W GRILL COMBINATION MICROWAVE ENERGY OUTPUT 800W MICROWAVE FREQUENCY 2450MHz OUTSIDE DIMENSIONS W X H X D 465 x 279 x 360 mm 18 3 x 11 0 x 14 2 in CAVITY DIMENSIONS W X H X D 290 x 220 x 306 mm 11 4 x 8 7 x 12 0 in NET WEIGHT APPROX 12 3Kg 27 2 lbs TIMER 59min 00 sec FUNCTION SELECTIONS MICROWAVE POWER SELECTIONS 5 LEVELS CAVITY VOLUME 0 7 Cu Ft UV LAMP 10W ...

Page 5: ...4 EXTERNAL VIEW 1 OUTER DIMENSION ...

Page 6: ...ity 7 Glass cooking tray Made of special heat resistant glass The tray can be easily removed for cleaning Make sure it is correctly positioned indentation before operating Place food in a suitable container dish on the tray 8 Roller guide Supports the glass cooking tray 9 Coupler This fits over the shaft in the center of the ovens cavity floor This is to remain in the oven for all cooking 10 UV la...

Page 7: ... and to defrost foods by weight or time 4 Clock Used to set clock 5 Display Cooking time power level indicators and present time are displayed 6 Stop Clear Used to stop the oven operation or to erase all entries 7 Strat Easy cook Used to start the oven operation and also increase the reheat time by 30 seconds 8 Dial Knob Used to set the time and weight EXTERNAL VIEW ...

Page 8: ...r source This microwave oven requires a current of approximately 10 amperes 120Volts 60Hz grounded outlet Power supply cord is about 0 8 meters long 1 A short power supply cord is provided to reduce the risks resulting from becoming entangled in or tripping over a longer cord 2 Longer cord sets or extension cords are available and may be used if care is exercised in their use 3 If a long cord or e...

Page 9: ...stops cooking and all information retained To erase all information except the present time touch the Stop Clear button once more If the oven door is opened during the oven operation all information is retained 11 If the Start button is touched and the oven does not operate check the area between the door and door seal for obstructions and make sure the door is closed securely The oven will not st...

Page 10: ... repair work 2 Warning about the electric charge in the high voltage capacitor For about 30 seconds after the operation stopped and 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 12A fuse is blown out due t...

Page 11: ...e cabinet backward 2 To remove door assembly 1 Remove screws which secure the stopper hinge top 2 Remove the door assembly from top plate of cavity 3 Reverse the above for reassembly After replacing the door assembly perform a check of correct alignment with the hinge and cavity front plate NOTE ...

Page 12: ...34R0S 1 A05 3517002800 BARRIER SCREEN I PET 0 1 1 A06 3512300200 GASKET DOOR PP 1 A07 3513100730 HOOK POM BLACK 1 A08 3515101320 SPRING HOOK HSW 3 1 A09 7112402011 SCREW TAPPING T1 TRS 4x20 MFZN 2 A10 3511606100 DECORATOR DOOR R STS304 T0 5H L 1 A11 3512603220 HANDLE DOOR CR T0 9 1 A12 3515307300 SUPPORTER HANDLE ABS SG 175 2 A13 3511605900 DECORATOR DOOR U STS304 T0 5H L 1 A14 3511606200 DECORATO...

Page 13: ...nd then push the door to contact the door seal to oven front surface Tighten a screw 2 To reduce gap located on part B Loosen two screws on stopper hinge under and then push the door to contact the door seal to oven front surface Tighten a screw A small gap may be acceptable if the microwave leakage does not exceed 4mW cm NOTE 2 DISASSEMBLY AND ASSEMBLY ...

Page 14: ... 161 T0 15 1 B04 3515501530 WINDOW DISPLAT PMMA 1 B05 3516726200 CONTROL PANEL ABS SG 175 SG 0760D 1 B06 3516907480 BUTTON FUNCTION ABS SG 175 SG 0760D 1 B07 3514321440 PCB SUB AS KOR 637V 1 B08 3514323330 PCB MAIN AS KOR 637V0A 1 B09 7122401211 SCREW TAPPING T2S TRS 4x12 MFZN 3 B10 7621301011 SCREW TAPPING T2 PAN 3x10 PW MFZN 5 B11 3516908520 BUTTON FUNCTION C ABS SG 175 SG 0760D 2 B12 3511605120...

Page 15: ...wiring 7 To remove magnetron 1 Remove a screw which secure the magnetron 2 Remove the magnetron 3 Reverse the above steps for reassembly DISASSEMBLY AND ASSEMBLY Never install the magnetron without the metallic gasket plate which is packed with each magnetron to prevent microwave leakage Whenever repair work is carried out on magnetron check the microwave leakage It shall not exceed 4mW for a full...

Page 16: ...ide assembly 4 Pull the fan from the motor shaft 5 Remove two screws which secure the motor shaded pole 6 Remove the motor shaded pole 7 Reverse the above steps for reasembly 9 To remove H V transformert 1 Remove four screws holding the H V transformer 2 Remove the H V transformer 3 Reverse the above steps for reassembly DISASSEMBLY AND ASSEMBLY ...

Page 17: ...emove the socket starter I from the socket starter O 5 Remove the terminal starters from the socket starter I 6 Remove the starter glow from the socket starter I 7 Remove the lamp germicidal from the cover lamp DISASSEMBLY AND ASSEMBLY 8 Remove the socket lamp 9 Remove the terminal lamp 10 Reverse the above steps for reasembly 11 To remove the ballast 1 Remove two screws holding the ballast 2 Remo...

Page 18: ...tch to bring it under NO condition and presses the button of the secondary interlock switch to bring it under ON condition 3 Adjustment steps a Loosen the one mounting screw b Adjust interlock switch assembly position c Make sure that lock lever moves smothly after adjustment is completed d Tighten completely one mounting screw Door open monitor switch rear Hook Primary interlock switch Interlock ...

Page 19: ...of low voltage transformer Malfunction of interlock monitor switch Defective low voltage transformer Check continuity of interlock monitor switch with door closed COM C Check continuity of primary interlock switch contact with door partially open until interlock monitor switch contact close COM NO Shorted contacts of primary interlock switch Fuse again blows Disconnect high voltage fuse and operat...

Page 20: ...chanism And Adjustment NOTE CONDITION CHECK RESULT CAUSE REMEDY Turn table motor and oven lamp do not turn on No Continuity Adjust or replace Adjust or replace Replace Replace Malfunction of primary interlock switch No Continuity 0 V Approx 15 VDC Check continuity of primary interlock switch Check continuity of secondary interlock and D O M switches Check D C voltage being supplied to RELAY RY2 co...

Page 21: ...ay coil REMEDY Replace Replace Replace Replace Replace Replace Replace Replace No microwave oscillation Check continuity of high voltage rectifier in forward and backward direction with DC megger Check continuity of high voltage capacitor terminals with wires removed Connect megger leads to magnetron terminal and magnetron body Check resistance of primary and secondary coil of high voltage transfo...

Page 22: ...ting down 9 Display counts down noticeably too fast while cooking 10 Display does not show the time of day when clear pad is touched 11 Oven lamp and turntable motor do not stop although cooking is finished Check if the RELAY 2 contacts close if they are close replace touch control circuit TROUBLE SHOOTING GUIDE Before following the particular steps listed above in the trouble shooting guide for t...

Page 23: ...efective ballast or UV lamp REMEDY Adjust or replace Replace Replace No purification Check D C Voltage being supplied to RELAY RY3 Coil Check continuity of secondary interlock and D O M switch Check continuity of primary interlock switch No Continuity Malfunction of primary interlock and D O M switch Faulty cantacts of RELAY RY3 or open relay coil Adjust or replace No Continuity ...

Page 24: ...he load is immediately placed on the center of the shelf which is 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 operating at full power The filament heat up time for magnetron is not included 6 The initial and final temperature of water is selected so th...

Page 25: ...et door seem door viewing screen the exhaust air vents and the suction air vents 3 Measuring should be 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 perpendicular to the areas making sure the probe end at the base of the cone does not get closer than 2 in...

Page 26: ... 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 should be used to check the front back resistance of the diode otherwise an infinite resistance amy be read in both directions A normal diode s resistance will be infinite in one direction and several hundred K...

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

Page 28: ... 1 PIN 2 21 30 34 5VDC 2 IC 1 PIN 35 3 IC 1 PIN 31 OR 32 NO MEASURE POINT WAVE FORM REMEDY REMARK 1 MP1 DC 5V 0 25V Replace VL1 EC1 NO LOAD 2 MP2 DC 12V 2 0V Replace EC2 D10 11 12 NO LOAD Each measure point must be measured with GND points NOTE 1 Refer to Circuit Diagram point 4 2 Secondary side voltage of the low voltage transformer changes in proportion to fluctuation of power source voltage 3 T...

Page 29: ...MP1 28 PRINTED CIRCUIT BOARD MP2 ...

Page 30: ...29 PRINTED CIRCUIT BOARD ...

Page 31: ...ital clock does not operate properly refer to Circuit Diagram Point 5 POINT STATE A B RELAY 2 ON 5V DC GND RELAY 2 OFF GND 12VDC POINT STATE A B RELAY 2 ON 5V DC GND RELAY 2 OFF GND 12VDC POINT STATE A B 1 DOOR OPEN OPEN 5VDC 2 DOOR CLOSED CLOSE GND CHECK NO METHOD REMEDY 1 Check the stage ON OFF of the door open monitor switch by resistance measurement Replace door open monitor switch POINT WAVE ...

Page 32: ...31 2 P C B CIRCUIT DIAGRAM PRINTED CIRCUIT BOARD ...

Page 33: ...RBON FILM R8 9 11 15 21 101 102 1 6W 1K 5 RD AZ102J 7 19 R CARBON FILM R13 1 6W 100K 5 RD AZ104J 1 20 R CARBON FILM R14 1 6W 100 5 RD AZ101J 1 21 R CARBON FILM R16 18 1 6W 10K 5 RD AZ103J 3 22 R CARBON FILM R19 1 6W 1M 5 RD AZ105J 1 23 R CARBON FILM R20 1 4W 27 5 RD 4Z270J 1 24 R CARBON FILM R12 1 6W 4 7K 5 RD AZ472J 1 25 IC REGULATOR VL1 MC7905C 1MC7905C 1 26 TRANSISTOR Q1 5 7 10 KRA 106M TZRA106...

Page 34: ...33 EXPLODED VIEW AND PARTS LIST 1 DOOR ASSEMBLY Refer to Disassembly and assembly 2 CONTROL PANEL ASSEMBLY Refer to Disassembly and assembly 3 TOTAL ASSEMBLY ...

Page 35: ...REW TAPPING T2S TRS 4 12 MFZN 1 F16 7122401211 SCREW TAPPING T2S TRS 4 12 MFZN 1 F17 7121403011 SCREW TAPPING T2S PAN 4X30 MFZN 2 F18 3963821610 MOTOR SHADED POLE 120V 60HZ MW10XA MO1 1 F19 3512517000 GUIDE WIND PP 1 F20 3511800300 FAN PP 30 GLASS 1 F21 3518002400 MAGNETRON 2M218J F 1 F22 3516004000 SPECIAL SCREW T2 BOLT FLANGE 5X12 DACRO 1 F23 7272400811 SCREW TAPTITE TT3 TRS 4X8 MFZN 1 F24 35130...

Page 36: ...8905300 THERMOSTAT OFF 75 ON 65 H 187 NR 1 F45 3513003400 HOLDER THERMOSTAT PBT 1 F46 7272400811 SCREW TAPTITE TT3 TRS 4X8 MFZN 1 F47 3511406200 COVER WAVE GUIDE HEATPROOF PP 1 F48 3517402000 COUPLER QUESTRA 1 F49 3514700710 ROLLER TEFLON 3 F50 3512517300 GUIDE ROLLER PP 5113MF6 A353B 1 F51 3517203600 TRAY GLASS 1 F52 3517207800 TRAY PP 1 F53 3518571200 STARTER GLOW FS 5 1 F54 3517800120 BALLAST F...

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