Page 1
S/M No. : OC9N2T7001 Service Manual Service Manual Microwave Oven Microwave Oven Model: KOC-9N2T7S Model: KOC-9N2T7S KOC-9N2T7S24 KOC-9N2T7S24 KOC-9N3T7S KOC-9N3T7S KOC-9N3T7R KOC-9N3T7R KOC-9N3T7S24 KOC-9N3T7S24 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.
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 if 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.
1. 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. SPECIFICATIONS MODEL KOC-9N2T7S, 9N2T7S24, 9N3T7S, 9N3T7S24 POWER SUPPLY 230V~50HZ, SINGLE PHASE WITH EARTHING MICROWAVE 1450W POWER GRILL 850W CONSUMPTION CONVECTION 2250W COMBINATION 2950W MICROWAVE ENERGY OUTPUT 900W(IEC705) MICROWAVE FREQUENCY 2450MHz OUTSIDE DIMENSIONS (W X H X D) 542X329X503mm (21.3X13.0X19.8 in.) CAVITY DIMENSIONS (W X H X D) 350X230X355mm (13.8X9.1X14.0 in.)
2. FEATURE DIAGRAM 11.DOOR HOOK When the door is closed, it will automatically lock shut. If door is opened while oven is operating, the magnetron will immediately stop operating. 12.DOOR VIEWING SCREEN Allows viewing of food. The screen is designed so that light can pass through, but not the microwave. 13.METAL RACK 14.TOP HEATER Turns on when convection, grill and combi cooking is selected.
This appliance is supplied with cable of special type, which, if damaged, 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 misaligned door, broken door or a dent in cavity.
5. CONTROL PANEL KOC-9N2T 1 Display : Cooking time, power level, indicators and present time are displayed. MW : When blinking, the oven is operating in MICROWAVE COOK. Grill : When blinking, the oven is operating in GRILL. Combi : When blinking, the oven is operating in COMBI.
Page 9
KOC-9N3T 1 Display : Cooking time, power level, indicators and present time are displayed. MW : When blinking, the oven is operating in MICROWAVE COOK. Grill : When blinking, the oven is operating in GRILL. Combi : When blinking, the oven is operating in COMBI. Defrost Weight : When blinking, the oven is operating in WEIGHT DEFROST.
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.
Page 11
1. To remove cabinet 1) Remove four screws on cabinet back. 2) Push the cabinet backward. 2. 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 for assemby.
Page 12
3. To remove door parts. REF NO. PART CODE PART NAME DESCRIPTION Q’TY REMARK 3512204830 FRAME DOOR ABS SR-0320 3517007140 GLASS T3.2 KOC-9N2T7S, 9N3T7S, 9N3T7R BARRIER-SCREEN *O 3517007150 GLASS T3.2 MIRROR KOC-9N2T7S24, 9N3T7S24 3515304800 SUPPORTER HINGE*T SCP-1 T2.0 3516602200 DOOR PLATE SBHG-3A T0.7 3517007000 BARRIER-SCREEN*I TEMP GLASS T2.0...
Page 13
(1) Remove the gasket door from door plate. (2) Remove the door frame from door plate. (3) Remove the stopper hinge top from door plate. (4) Remove the spring and the hook. (5) Remove the barrier screen outer from door frame. (6) Reverse the above steps for reassembly.
Page 15
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). KOC-9N3T REF NO.
Page 16
6. 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. High voltage circuit wiring 7.
Page 17
8. To remove wind guide assembly. 1) Remove a screw for earthing. 2) Remove the noise filter from the wind guide. 3) Remove a screw which secure the wind guide 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.
Page 18
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). 10. To remove Top heater assembly parts. REF NO.
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). 11. To remove Rear heater assembly parts. REF NO.
7. 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.
8. 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 tranformer, disconnect one load wire from these parts and check continuity with the AC plug removed.
Page 22
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). CONDITION CHECK RESULT CAUSE...
Page 23
TROUBLE 3) No microwave oscillation even though fan motor rotates. CONDITION CHECK RESULT CAUSE REMEDY Check continuity of Replace Defective continuity high voltage fuse microwave high voltage oscillation fuse No microwave oscillation Continuity Check continuity of Defective high voltage capacitor terminals high voltage with wires removed transformer...
Page 24
(TROUBLE 4) Grill heater (upper heater) is not heated; food will not become hot. CONDITION CHECK RESULT CAUSE REMEDY Malfunction of Adjust or Check continuity of Grill heater is primary Interlock replace continuity primary interlock switch not heated. switch Adjust or Malfunction of Check continuity of replace...
Page 25
(TROUBLE 6) The following visual conditions inditions indicate a probable defective touch control Circuit or button P.C.B. assembly 1. Incomplete segments. 1) segment missing 2) partial segments missing 3) digit flickering other than normal fluorescent slight flickering 2. A distinct change in the brightness of one or more numbers exists in the display 3.
9. 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. A cylindrical container of borosilicate glass is used for the test. It has a maximum thickness of 3mm, an external diameter of approximately 190mm and a height of approximately 90mm.
2. MICROWAVE RADIATION TEST WARNING 1. Make sure to check the microwave leakage before and after repair of adjustment. 2. Always start measuring of an unknown field to assure safety for operating personnel from microwave energy. 3. Do not place your hands into any suspected microwave radiation field unless the safe density level is known. 4.
3. 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.
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 32
: 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). PART CORD PART NAME DESCRIPTION Q'TY REMARK KOC-9N2T7S 3511725500 DOOR AS KOC-9N3T7R 9N3T7S, 9N3T7R KOC-9N2T7S24, 3511725520 KOC-9N3T7S24...
Page 33
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). PART CORD PART NAME DESCRIPTION Q'TY...
Page 34
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). PART CORD PART NAME DESCRIPTION Q'TY...
T : 250 ns(4MHz) - Check method MEASURE POINT WAVE FORM REMEDY REMARK DC 5V 5% Replace ZD3, EC1(KOC-9N2T7S/R) NO LOAD Replace ZD2, EC1(KOC-9N3T7S/R) DC 24V 20% Replace D18-D21, EC5(KOC-9N2T7S/R) NO LOAD Replace D18-D21, EC4(KOC-9N3T7S/R) NOTE: Each measure point must be measured with GND points.
Page 38
3. Case of no microwave oscillation 1) When touching M/W button, oven lamp turns on and Fan motor and turntable rotate, and cook indicator in display comes on. *Cause: RELAY 1 does not operate. D7(KOC-9N3T7S/R) D8(KOC-9N2T7S/R) RY1(KOC-9N3T7S/R) Q5(KOC-923T9S/R) RY2(KOC-9N2T7S/R) STATE...
Page 39
4. Case of no heating of top grill When touching GRILL or COMBI button, oven lamp turns on and fan motor and turntable rotate, and cook indicator in display comes on. *Cause: RELAY 2 does not operate. (KOC-9N3T7S/R) (KOC-9N2T7S/R) GRILL RY2(KOC-9N3T7S/R) Q6(KOC-9N2T7S/R) RY3(KOC-9N2T7S/R)
Page 40
6. Case of no stopping of the count down timer When the door is opened during operation, the count down timer does not stop. D.O.M SW (KOC-9N2T7S/R) D.O.M SW (KOC-9N3T7S/R) POINT STATE DOOR OPEN OPEN +5V DC DOOR CLOSED CLOSE...
Page 43
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). NAME SYMBOL SPECIFCATION PART CODE...
Page 44
10mm WIRE COPPER J4,14~16,21~23 1/0.52 TIN COATING 85801052GY 12.5mm WIRE FLAT 15/90 WH C WSJ-159007 ONLY FOR SELECTION JUMPER SJ5,7,8 1/0.52 TIN COATING 85801052GY KOC-9N2T7S PCB SUB M265 SUB PCB 3514330210 CONNECTOR FILM CN101 HLEM15R-1 4CW215RBD0 SW TACT SW101~108,110,111 KPT-1115AM...
Need help?
Do you have a question about the KOC-9N2T7S and is the answer not in the manual?
Questions and answers