S/M NO. : C984T2S132 Service Manual Microwave Oven Model: KOC-984T2S13 ✔ Caution : In this Manual, some parts can be changed for improving, their performance without notice in the parts list. So, if you need the latest parts information,please refer to PPL(Parts Price List) in Service Information Center (http://svc.dwe.co.kr). DAEWOO ELECTRONICS CO., LTD. http://svc.dwe.co.
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.
SAFETY AND PRECAUTIONS 1. FOR SAFE OPERATION Damage that allows the microwave energy (that cooks or heats the food) to escape will result in poor cooking and may cause serious bodily injury to the operator. IF ANY OF THE FOLLOWING CONDITIONS EXIST, OPERATOR MUST NOT USE THE APPLIANCE. (Only a trained service personnel should make repairs.) (1) A broken door hinge. (2) A broken door viewing screen. (3) A broken front panel, oven cavity. (4) A loosened door lock. (5) A broken door lock.
SPECIFICATIONS MODEL KOC-984T2S13 POWER SUPPLY 240V-50Hz POWER CONSUMPTION MICROWAVE 1450 W GRILL 1200W CONVECTION 1550W PROGRAM COOK 1850W COMBINATION 1550W (Sequential) MICROWAVE ENERGY OUTPUT 1000W (IEC705) MICROWAVE FREQUENCY 2450MHz OUTSIDE DIMENSIONS (W X H X D) 526 X 345 X 496 mm (20.7 X 13.6 X 19.5 inch) CAVITY DIMENSIONS (W X H X D) 335 X 250 X 339 mm (13.2 X 9.8 X13.3 inch) NET WEIGHT Approx. 21 kg (46.3 Ibs.
EXTERNAL VIEW 345 320 1.
2. FEATURE DIAGRAM 1 Door seal—Door seal maintains the microwave energy within the oven cavity and prevents microwave leakage. 6 Safety interlock system 7 Control panel 8 Turntable tray—Rotates during cooking and ensure even distribution of Microwaves. It can also be used as a cooking utensil. 2 Door hook—When the door is closed, it will automatically shut. If the door is opened while the oven is operating, the magnetron will immediately stop operating.
INSTALLATION 1. Steady, flat location This microwave oven should be set on a steady, flat surface. This microwave oven is designed for counter top use only. 2. Leave space behind and side All air vents should be kept a clearance. If all vents are covered during operation, the oven may overheat and, eventually, cause failure. 3. Away from Radio and TV sets Poor television reception and radio interference may result if the oven is located close to a TV, Radio, antenna or feeder and so on.
CONTROL PANEL When blinking, the oven is operating in “COMBI” cooking mode. When binking, the oven is operating in “WEIGHT DEFROST” cooking mode. When blinking, the oven is operating in “GRILL” cooking mode. When blinking, the oven is operating in “TIME DEFROST” cooking mode. DEFROST When blinking, the oven is operating in “MICROWAVE” cooking mode. When blinking, the oven is operating in “PROGRAM COOK” cooking mode. When Blinking, the oven is operating in “PIE” cooking mode.
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 safety 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.
1. To remove cabinet 1) Remove four screws on cabinet back. 2) Push the cabinet backward. 2. To remove guide wind assembly 1) Remove two screws for earthing and for fixing to rear-plate. 2) Remove the noise filter from the guide wind. 3) Pull the fan from the motor shaft. 4) Remove two screws which secure the motor shaded pole. 5) Remove the motor shaded pole. 6) Reverse the above steps for reassembly.
3. To remove H.V. transformer 1) Remove four screws which secure the H.V. Transformer to the base plate. 2) Remove the H.V. Transformer. 3) Reverse the above steps for reassembly. 4. To remove high voltage capacitor 1) Remove a screw which secure the grounding ring terminal of the H.V. diode and the capacitor holder. 2) Remove the H.V. diode from the capacitor holder. 3) Reverse the above steps for reassembly.
5. To remove magnetron 1) Remove three screws which secure the magnetron. 2) Remove the magnetron. 3) Reverse the above steps for reassembly. CAUTION : 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/cm2 for a fully assembled oven with door normally closed.
✔ Caution: In this Service Manual, some parts can be changed for improving, their performance without notice in the parts list. So, if you need the latest parts information, please refer to PPL(Parts Price List) in Service information Center(http://svc.dwe.co.kr) 6. To remove control panel assembly (1) Remove a screw which secure the control panel assembly to the oven front plate. At the same time, draw forward the control panel assembly from the oven front plate. (2) Remove the dial knob.
✔ Caution: In this Service Manual, some parts can be changed for improving, their performance without notice in the parts list. So, if you need the latest parts information, please refer to PPL(Parts Price List) in Service information Center(http://svc.dwe.co.kr) 7. To remove door assembly 1) Remove two screws which secure the stopper hinge top. 2) Remove the door assembly from top plate of cavity. 3) Reverse the above steps for reassembly.
9. Method to reduce the gap between the door seal and the oven front surface. (1) To reduce gap located on part ‘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. A C B D (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 two screws.
10. To remove motor syncro and under heater: 1) Cut the syncro motor cover parts from the base plate. 2) Remove two screws which secure the motor syncro and supporter to bracket syncro motor. 3) Remove two screws and under heater assembly in cavity. 11. To remove grill heater assembly 1) Remove two screws which secure the cover insulator *t to top plate. 2) Remove the harness betweens heaters. 3) Remove two screws for removing heater brackets. 4) Remove heaters. 5) Reverse the above steps for reassembly.
12. To remove convection part assembly 1) Remove cover *b and cover insulator *b protecting convection part assembly. - release two lances of cover insulator *b. 2) Remove four screws which secure the convection part assembly to the cavity rear plate. 3) Remove a nut holding the convection fan and the pipe. 4) Remove twoscrews which secure the bracket motor to cover insulator. 5) Remove the cooling fan. 6) Remove two screws which secure the motor shaded pole to the bracket motor.
INTERLOCK MECHANISM AND ADJUSTMENT The door lock mechanism is a device which has been specially designed to completely eliminate microwave radiation when the door is opened during operation, and thus to perfectly prevent the danger resulting from the leakage of microwave. 1. Primary interlock switch When the door is closed, the hook locks the oven door. If the door is not closed properly, the oven will not operate. When the door is closed, the hook pushes the button of the microswitch.
TROUBLE SHOOTING GUIDE Following the procedures below to check if the oven is defective or not. 1. Check grounding before checking trouble. 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.
Condition Outlet has proper voltage. Fuse does not blow. Check Result Cause Remedy Check continuity of magnetron No Continuity Defective magnetron Check continuity of noise filter board No Continuity Defective noise filter board Replace Check continuity of power supply cord No Continuity Open power supply cord Replace Normal Defective touch control circuit. Adjust Replace NOTE : All these switches must be replaced at the same time, please refer to (7.
(TROUBLE 3) No microwave oscillation even though fan motor rotates.
(TROUBLE 4) Display shows all figures selected, but oven does not start cooking, even though desired program and time are set and start pad is tapped. Condition Check Fan motor, turn table motor and oven lamp do not turn on Result Cause Check continuity of primary interlock switch No Continuity Malfunction of primary interlock awitch Adjust or replace Check continuity of secondary interlock and D.O.M. switch No Continuity Malfunction of secondary interlock and D.O.M.
(TROUBLE 4) The following visual conditions indicate a probable defective touch control circuit or button P.C.B. assembly. 1. Incomplete segments (1) Segments missing (2) Partial segments missing (3) Digit flickering other than normal fluorescent slight flickering (4) 0 does not display when power is on. 2. A distinct change in the brightness of one or more numbers exists in the display. 3. One or more digits in the display are not on when they should be. DEFROST MW GRILLL COMBI WEIGHT - TIME 4.
BUTTON KEYBOARD CHECK PROCEDURE 1. Type of button names key matrix and circuit diagram The tact switch keyboard consists of 10 keys which configurations are described above. 2. Key check procedure To determine if the tact switch keyboard is defective or not, check the continuity of each button(key) contacts with a multimeter.
MEASUREMENT AND TEST 1. MEASUREMENT OF THE MICROWAVE POWER OUTPUT Microwave output power can be checked by indirectly measuring the temperature rise of a certain amount of water exposed to the microwave as directed below. PROCEDURE 1. Microwave power output measurement is made with the microwave oven supplied at rated voltage and operated at its maximum microwave power setting with a load of 1000±5cc of potable water. 2.
2. ELECTRICAL CONTINUITY CHECK OF INTERLOCK SWITCH NOTE : Remove the power plug from the wall receptacle before testing. PROCEDURE 1. Primary interlock switch 1) Disconnect two connectors from primary interlock switch. 2) Connect the ohm-meter leads between the terminals of the primary interlock switch. 2. Read the value of resistance between the terminals of the switch, when the door is opened, and when the door is closed. 3.
3. MICROWAVE RADIATION TEST WARNING : Make sure to check the microwave leakage before and after repair of adjustment. Always start measuring of an unknown field to assure safety for operating personnel from microwave energy. Do not place your hands into any suspected microwave radiation field unless the safe density level is known. Care should be taken not to place the eyes in direct line with the source of microwave energy.
4. COMPONENT TEST PROCEDURE • High voltage is present at the high voltage terminal of the high voltage transformer during any cooking cycle. • It is neither necessary nor advisable to attempt measurement of the high voltage. • Before touching any oven components or wiring, always unplug the oven from its power source and discharge the capacitor. 1. High voltage transformer (1) Remove connections from the transformer terminals and check continuity.
WIRING DIAGRAM 28
SCHEMATIC DIAGRAM 29
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EXPLODED VIEWS AND PARTS LIST 32
✔ Caution: In this Service Manual, some parts can be changed for improving, their performance without notice in the parts list. So, if you need the latest parts information, please refer to PPL(Parts Price List) in Service information Center(http://svc.dwe.co.
✔ Caution: In this Service Manual, some parts can be changed for improving, their performance without notice in the parts list. So, if you need the latest parts information, please refer to PPL(Parts Price List) in Service information Center(http://svc.dwe.co.
PRINTED WIRING BOARD 1. CIRCUIT CHECK PROCEDURE 1. Low Voltage Transformer check • The low voltage transformer is located on the P.C.B. • Measuring condition(input voltage) : 230VAC/50Hz KOC-984T2S13 L.V.T. : DMR-984FS 1 6 Terminal Voltage 7 1-3 230VAC/50Hz 6-7 10.5 VAC 7-8 10.5 VAC 9 - 10 2.6 VAC 8 9 3 5 10 Secondary side voltage of the low voltage transformer changes in proportion to fluctuation of power source voltage.
3. Display Problems NO CAUSE MEASUREMENT RESULT REMEDY 2.6 VAC Fix the pin 1&25 on the P.C.B. 1 Poor contact between P.C.B. and display filament Check the voltage of display pin 1&25 2 The display has some trouble in its segment or grid Refer to the display trouble shooting data below Replace P.C.B. assembly 3 Loss vacuum in the display Find white spot Replace P.C.B. assembly • The display trouble shooting data TROUBLE DISPLAY NAME & PIN NO. Grid 1 doesn’t come on.
4. Case of no microwave oscillation (1) Situation : When touching M/W button, oven lamp turns on, fan motor and turntable motor rotate and cook indicator in the display comes on. • CAUSE : Relay 1 (RY1) does not operate.
• Check method STAGE POINT A POINT B RELAY ON +5 VDC GND RELAY OFF GND +12 VDC 5. Case of no heating of upper heater When touching TEMP COOK & COMBI button, oven lamp turns on, fan motor and turntable motor rotate and cook indicator in the display comes on. • CAUSE : Relay 2 (RY2) does not operate. KOC-984T2S13 B RY2 G5G-1A-DT UPPER HEATER A Q8 KRC106M 39 D5 1N4148 • Check method STAGE POINT A POINT B RELAY ON +5 VDC GND RELAY OFF GND +12 VDC 6.
7. Case of no stopping of the count down timer When the door is opened during operation, the count down timer does not stop. KOC-984T2S13 CN2 R28 YW396-02V 4.7K COM R22 4.7K 1 2 47 D.O.M NO R23 330 C12 104 R25 4.7K C13 104 R24 100K B V1 A • Check method STAGE POINT A POINT B Door opened Open +5 VDC Door closed Closed GND NOTE : Check the state (ON, OFF) of the secondary interlock switch by resistance measurement. 8.
P.C.
✔ Caution: In this Service Manual, some parts can be changed for improving, their performance without notice in the parts list. So, if you need the latest parts information, please refer to PPL(Parts Price List) in Service information Center(http://svc.dwe.co.
DAEWOO ELECTRONICS CO., LTD. 686, AHYEON-DONG MAPO-GU SEOUL, KOREA C.P.O. BOX 8003 SEOUL, KOREA TELEX: DWELEC K28177-8 CABLE: “DAEWOOELEC” S/M NO. : C984T2S132 PRINTED DATE: Aug.
