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S/M NO. : C621Q0S001
Service Manual
Microwave Oven
Model: KOC-621Q0S
DAEWOO ELECTRONICS CO., LTD.
http://svc.dwe.co.kr Dec. 2001
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. (c) Before turning on power to the microwave oven for any service test or inspection within the microwave generating compartments, check the magnetron, wave guide or transmission line, and cavity for proper alignment, integrity, and connections. (d) Any defective or misadjusted 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 released to the owner. A microwave leakage check to verify compliance with the Federal performance standard should be performed on each oven prior to release to the owner.
TABLE OF CONTENTS
1. SAFETY AND PRECAUTIONS....................................................................................................................................2 2. SPECIFICATIONS ........................................................................................................................................................3 3. EXTERNAL VIEW.........................................................................................................................................................3 3-1. OUTER DIMENSION ..........................................................................................................................................3 3-2. FEATURE DIAGRAM .........................................................................................................................................4 4. INSTALLATION ............................................................................................................................................................5 5. CONTROL PANEL .......................................................................................................................................................6 6. DISASSEMBLY AND ASSEMBLY ..............................................................................................................................7 7. INTERLOCK MECHANISM AND ADJUSTMENT.....................................................................................................15 8. TROUBLE SHOOTING GUIDE ..................................................................................................................................16 9. MEASUREMENT AND TEST.....................................................................................................................................22 9-1. MEASUREMENT OF THE MICROWAVE POWER OUTPUT ........................................................................22 9-2. MICROWAVE RADIATION TEST ....................................................................................................................23 9-3. COMPONENT TEST PROCEDURE................................................................................................................24 9-4. COMPONENT ACTION....................................................................................................................................25 10. WIRING DIAGRAM...................................................................................................................................................26 11. EXPLODED VIEW AND PARTS LIST ..................................................................................................................27 11-1. DOOR ASSEMBLY.........................................................................................................................................27 12-2. CONTROL PANEL ASSEMBLY.....................................................................................................................27 13-3. TOTAL ASSEMBLY ........................................................................................................................................27 12. PRINTED CIRCUIT BOARD ....................................................................................................................................29 13. P.C.B CIRCUIT DIAGRAM.......................................................................................................................................33
1
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) A broken door viewing screen. (3) A broken front panel, oven cavity. (4) A loosened door lock. (5) A broken door lock. The door gasket plate and oven cavity surface should be kept clean. No grease, soil or spatter should be allowed to build up on these surfaces or inside the oven. DO NOT ATTEMPT TO OPERATE THIS APPLIANCE WITH THE DOOR OPEN. The microwave oven has concealed switches to make sure the power is turned off when the door is opened. Do not attempt to defeat them. DO NOT ATTEMPT TO SERVICE THIS APPLIANCE UNTIL YOU HAVE READ THIS SERVICE MANUAL.
2. FOR SAFE SERVICE PROCEDURES.
1. If the oven is operative prior to servicing, a microwave emission check should be performed prior to servicing the oven. 2. If any 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 the owner, (3) attempt to ascertain the cause of the excessive leakage, (4) 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, the service person should tell the user not to operate the oven and contact the manufacturer immediately.
IMPORTANT
The wire in this mains lead coloured in accordance with the following code. Green-and-yellow : Earth Blue : Neutral Brown : Live As the colours of the wires in the mains lead of this appliance may not correspond with the coloured markings identifying the terminals in your plug, proceed as follows: The wire which is coloured green-and-yellow must be connected to the terminal in the plug which is marked with the letter `E', earth symbol or coloured green-and-yellow. The wire which is coloured blue must be connected to the terminal which is marked with the letter `N' or coloured black. The wire which is coloured brown must be connected to the terminal which is marked with the letter `L' or coloured red.
NOTE : This oven is designed for counter-top use only.
2
2. SPECIFICATIONS
MODEL POWER SUPPLY MICROWAVE POWER CONSUMPTION GRILL OVEN COMBINATION MICROWAVE ENERGY OUTPUT MICROWAVE FREQUENCY OUTSIDE DIMENSIONS (W X H X D) CAVITY DIMENSIONS (W X H X D) NET WEIGHT TIMER FUNCTION SELECTIONS POWER SELECTIONS CAVITY VOLUME * Specifications are subject to change without notice. KOC-621Q0S 230V~50HZ, SINGLE PHASE WITH EARTHING 1250W 1250W 1650W 2500W 800W(IEC705) 2450MHz 470X285X376mm (18.5X11.2X14.8 in.) 295X167X300mm (11.6X6.6X11.8 in.) APPROX. 15kg (33.1 lbs.) Oven: 99 minutes, M/W: 60 minutes, Grill: 30 minutes MICROWAVE/ GRILL/ OVEN/ COMBINATION 10 LEVELS 0.6 Cu. Ft
3. EXTERNAL VIEW
3-1. OUTER DIMENSION
470
376
285
3
3-2. FEATURE DIAGRAM
1 2 3 4 5
M/W
Def.
Grill
Temp
g
Auto Cook 1. Roast Beef 3. Roast Chicken 5. Vegetable 2. Roast Pork 4. Fish Fillets
M/W
Defrost
Grill
1000g
10m.
Combi
100g
1m.
6
Temp
10s.
Clock
Auto Cook
Stop/ Clear
Start/ Speedy cook
Combi
KOC-621Q
e
w
q 7 8 9 0
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.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. UNDER HEATER 18. METAL RACK 19.TURNTABLE TRAY Rotates during cooking and ensure even distribution of Microwaves. It can also be used as a cooking utensil. 10.TRAY GUIDE This must always be used for cooking together with the turntable tray. 11. COUPLER This fits over the shaft in the center of the ovens cavity floor. This is to remain in the oven for all cooking. 12. OVEN FRONT PLATE 13.DOOR SEAL Door seal maintains the microwave energy within the oven cavity and prevents microwave leakage.
4
4. 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. Position the oven as far from them as possible.
4. Away from heating appliances and water taps
Keep the oven away from hot air, steam or splash when choosing a place to position it, or the insulation might be adversely affected and breakdowns occur.
5. Power supply
· Check your local power source. This microwave oven requires a current of approximately 12 amperes, 230V, 50Hz. · Power supply cord is about 1.2 meters long. · The voltage used must be the same as specified on this oven. Using a higher voltage may result in a fire or other accident causing oven damage. Using low voltage will cause slow cooking. We are not responsible for damage resulting from use of this oven with a voltage of ampere fuse other than those specified. · 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. If any of the above are visible, DO NOT INSTALL, and notify dealer immediately.
7. Do not operate the oven if it is colder than room temperature.
(This may occur during delivery in cold weather.) Allow the oven to become room temperature before operating.
EARTHING INSTRUCTIONS
This appliance must be earthed. In the event of an electrical short circuit, earthing reduces the risk of the electric shock by providing an escape wire for the electric current. This appliance is equipped with a cord having a earthing wire with a earthing plug. The plug must be plugged into an outlet that is properly installed and earthed.
WARNING Improper use of the earthing plug can result in a risk of electric shock. Consult a qualified electrician of serviceman if the earthing instructions are not completely understood, or if doubt exists as to whether the appliance is properly earthed, and either: If it is necessary to use an extension cord, use only a 3-wire extension cord that has a 3-blade earthing plug, and a 3-slot receptacle that will accept the plug on the appliance. The marked rating of the extension cord should be equal to or greater than the electrical rating of the appliance, or Do not use an extension cord.
5
5. CONTROL PANEL
BUTTONS 1. m/w - Press to select microwave power level. 2. defrost - 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 to set time and weight. 8. 10s. - Press to set time.
M/W Def. Grill Temp g
9. clock - Use to set clock. 10. auto cook - Press to select auto cook menu. 11. stop/clear - Press once to stop a programme, and twice to cancel a programme. 12. start/speedy cook - Press to start a programme, also for speedy start (each press adds 30 seconds microwave cooking time).
Auto Cook 1. Roast Beef 3. Roast Chicken 5. Vegetable 2. Roast Pork 4. Fish Fillets
1 3 4 5 9 q
M/W
Defrost
2 6 7 8 0 w
Grill
1000g
10m.
Combi
100g
1m.
Temp
10s.
Clock
Auto Cook
Stop/ Clear
Start/ Speedy cook
Combi
KOC-621Q
6
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.
SHORT
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.
7
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. NOTE: After replacting the door assembly, perform a check of correct alignment with the hinge and cavity front plate.
3. To remove door parts.
REF NO. A01 A02 A03 A04 A05 A06 A07 A08
PART CODE 3512203410 3517004800 3515203000 3511709400 3517004700 3512301100 3513101000 3515101700
PART NAME FRAME DOOR BARRIER-SCREEN *O STOPPER HINGE *T AS DOOR PAINTING AS BARRIER-SCREEN *I GASKET DOOR HOOK SPRING HOOK
DESCRIPTION ABS TEMP GLASS T3.2 KOC-621S5J KOC-621S5J TEMP GLASS T3.0 PBT POM PW1
Q'TY 1 1 1 1 1 1 1 1
REMARK
8
(1) Remove the gasket door(A06) from door plate. (2) Remove the door frame (A01) from door plate(A04). (3) Remove the stopper hinge top(A03) from door plate(A04). (4) Remove the spring(A08) and the hook(A07). (5) Remove the barrier screen outer(A02) from door frame(A01). (6) Reverse the above steps for reassembly.
4. 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. (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.
A
M/W
Def.
Grill
Temp
g
Auto Cook 1. Roast Beef 3. Roast Chicken 5. Vegetable 2. Roast Pork 4. Fish Fillets
M/W
Defrost
Grill
1000g
10m.
Combi
100g
1m.
Temp
10s.
Clock
Auto Cook
Stop/ Clear
Start/ Speedy cook
Combi
KOC-621Q
B
NOTE : A small gap may be acceptable if the microwave leakage does not exceed 4mW/cm2.
9
5. To remove control panel parts.
REF NO. B01 B02 B03 B04
PART CODE 3518523500 3516715810 3514325720 7112401211
PART NAME SWITCH MEMBRANE CONTROL-PANEL PCB AS SCREW TAPPING
DESCRIPTION KOC-621Q0S ABS KOC-621Q0S T1 TRS 4X12 MFZN
Q'TY 1 1 1 4
REMARK
(1) Remove four screws(B04) which secure the PCB AS(B03). (2) Pull out the PCB AS(B03) from control panel(B02). (3) Reverse the above steps for reassembly.
10
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.
x High voltage circuit wiring
7. To remove magnetron.
1) Remove a screw 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.
Metallic gasket plate
Magnetron antenna
Cooling fin Filament terminal
11
8. To remove wind guide assembly.
1) Remove a screw for earthing. 2) Remove the noise filter from the wind guide. 3) Remove two screws 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. 7) Remove the motor shaded pole. 8) Reverse the above steps for reasembly.
9. To remove H.V.transformer.
1) Remove four screws holding the H.V.transformer. 2) Remove the H.V.transformer. 3) Reverse the above steps for reassembly.
12
10. To remove Top heater assembly parts.
REF NO. 1 2 3 4 5 6
PART CODE 7112401011 3511409700 3512513110 7392500011 7392500011 3512803300
PART NAME SCREW TAPPING COVER INSU *T AS GUIDE AIR OUTLET NUT HEX NUT HEX HEATER
DESCRIPTION T1 TRS 4*10 MFZN KOC-621Q0S SA1D-80 T0.5 6N-2-5 MFZN 6N-2-5 MFZN 230V 1150W 1B08965
Q'TY 2 1 1 1 1 1
REMARK
1) Remove two screws 1 then pull out cover insulator *t as 2 and guide air outlet 3. 2) Remove a hex nut 4 and hex nut 5. 3) Pull out heater. 4) Reverse the above steps for reassembly.
13
11. To remove Motor synchro. And Under heater assembly parts.
CUTTING (8EA)
REF NO. 1 2 3 4 5
PART CODE 7122400811 7113400814 3512802000 3515304000 3511404410
PART NAME SCREW TAPPING SCREW TAPPING HEATER *U SUPPORTER HEATER COVER HEATER *U
DESCRIPTION T2S TRS 4*8 MFZN T1 BIN 4*8 MFNI 230V 400W R1837400 STS430 T0.5 STS430-2B/HL T0.6
Q'TY 1 1 1 1 1
REMARK
1) Cut the cover parts from the base plate. 2) Remove a screw and then pull out Motor syncro. 3) Remove a screw1 and then pull out the Under heater *U. assembly. 4) Remove a screw2 . 5) Pull out the Heater *U 3 from the Cover heater *U 5 . 6) Reverse the above steps for reassembly.
14
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. 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. Then the button of the primary interlock switch bring it under ON condition. (2) Secondary interlock switch and interlock monitor switch When the door is 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 switch to bring it under ON condition. ADJUSTMENT : Interlock monitor switch When the door is closed, the interlock monitor switch should be opened before other switches are closed. When the door is opened, the interlock monitor switch should be closed after other switches are opened. (3) Adjustment steps a) Loosen the two mounting screws. b) Adjust interlock switch assembly position. c) Make sure that lock lever moves smoothly after adjustment is completed. d) Tighten completely two mounting screws. NOTE : Microwave emission test should be performed after adjusting interlock mechanism. If the microwave emission exceed 4mW/cm2, readjust interlock mechanism.
15
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. To do otherwise may result in a false reading or damage to your meter.
NOTE : When electric parts are checked, be sure the power cord is not inserted the wall outlet. Check wire harness, wiring and connection of the terminals and power cord before check the parts listed below.
(TROUBLE 1) Oven does not operate at all : any inputs can not be accepted.
CONDITION Fuse blows.
CHECK Check continuity of interlock monitor switch with door closed ( COMNC )
RESULT Continuity (COMNC) No continuity
CAUSE Malfunction of Interlock monitor switch
REMEDY Replace
Check continuity of both primary and secondary interlock switch with door closed
No Continuity Continuity
Malfunction of interlock switch
Replace
Continuity Check continuity of primary interlock switch contact with door partially open until interlock monitor switch contact close ( COMNC close ) 0 or infinite Approx. 790 ( normal )
Shorted contacts of primary interlock Switch
Replace
Check continuity of primary winding of low voltage transformer
Defective low voltage transformer
Replace
Disconnect high voltage fuse and operate the unit
Fuse again blows
Defective high voltage transformer
Replace
16
CONDITION Outlet has proper voltage fuse does not blow?
CHECK Check continuity of magnetron
RESULT No continuity
CAUSE Defective magnetron.
REMEDY
Replace
Check continuity of noise filter board
No continuity
Defective line filter board
Replace
Check continuity of power supply cord
No continuity
Open power supply cord
Replace
continuity
Defective touch control circuit
Replace
NOTE : All these switches must be replaced at the same time, please refer to (7.Interlock mechanism and adjustment) 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 Turn table motor and oven lamp do not turn on
CHECK Check continuity of primary interlock switch
RESULT No continuity
CAUSE Malfunction of primary interlock switch Malfunction of secondary Interlock and D.O.M switch Defective touch control Circuit
REMEDY Adjust or replace
Check continuity of secondary interlock and D.O.M switch Check D.C voltage being supplied to RELAY(RY5) coil
No continuity
Adjust or replace
0V
Replace
Approx. 13V DC
Fault contacts of RELAY (RY5) or open relay coil.
Replace
17
TROUBLE 3) No microwave oscillation even though fan motor rotates.
CONDITION No microwave oscillation
CHECK Check continuity of high voltage fuse
RESULT No continuity
CAUSE Defective high voltage fuse
REMEDY Replace
No microwave oscillation
Check continuity of high voltage capacitor terminals with wires removed Check continuity of high voltage rectifier in forward and backward direction with DC megger Connect megger leads to magnetron terminal and magnetron body
Continuity
Defective high voltage transformer Defective high voltage rectifier
1
Continuity in backward direction
Replace
Continuity
Defective magnetron
2
Check D.C voltage being supplied to RELAY (RY1) coil
0V
Defective touch control circuit
Replace
Approx. 13V DC
Faulty contacts of RELAY (RY1) or open relay coil
Replace
1 Check resistance of primary
0 or
and secondary coil of high voltage transformer
Defective high voltage transformer
Replace
1 Check continuity of filament
No continuity
terminal of high voltage transformer
2 Check continuity of
Defective high voltage transformer Defective magnetron
Replace
magnetron heater with wires removed
No continuity
Replace
18
(TROUBLE 4) Grill heater (upper heater) is not heated; food will not become hot. CONDITION CHECK Check continuity of primary interlock switch RESULT No continuity CAUSE Malfunction of primary Interlock switch Malfunction of secondary interlock switch Defective heater REMEDY Adjust or replace
Grill heater is not heated.
Check continuity of secondary interlock switch
No continuity
Adjust or replace
Check continuity of heater Check D.C voltage being supplied to RELAY (RY3) coil
No continuity
Replace
0V
Defective touch control circuit
Replace
Approx. 13V DC
Faulty contacts of RELAY (RY3) or open relay coil
Replace
(TROUBLE 5) Fan motor does no rotate.
CONDITION Fan does not rotate.
CHECK Check continuity of primary interlock switch
RESULT No continuity
CAUSE Malfunction of primary Interlock switch Malfunction of secondary interlock switch Defective fan
REMEDY Adjust or replace
Check continuity of secondary interlock switch Check continuity of fan Check D.C voltage being supplied to RELAY (RY6) coil
No continuity
Adjust or replace
No continuity
Replace
0V
Defective touch control circuit
Replace
Approx. 13V DC
Faulty contacts of RELAY (RY6) or open relay coil
Replace
19
(TROUBLE 6) Lower heater is not heated; food will not become hot. CONDITION Lower heater Is not heated CHECK Check continuity of Primary interlock switch RESULT No continuity CAUSE Malfunction of primary Interlock switch Malfunction of secondary interlock switch Defective heater REMEDY Adjust or Replace
Check continuity of secondary interlock switch Check continuity of heater Check D.C voltage Being supplied to RELAY (RY4) coil
No continuity
Adjust or replace
No continuity
Replace
0V
Defective Touch control circuit Faulty contacts of RELAY (RY4) or open relay coil
Replace
Approx. 13V DC
Replace
(TROUBLE 7) The following visual conditions indicate a probable defective touch control Circuit or Membrane. 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. One or more digits in the display are not on when they should be. 4. Display does not count down or up with time cooking or clock operation. 5. Oven is programmable and cooks normally but no display shows. 6. Display obviously jumps in time while counting down. M/W Def. Grill Temp 7. Display counts down noticeably too fast while cooking.
g
CONDITION Display does not show programming at all, even if keyboard is touched.
CHECK Check each pad for continuity of the pad
RESULT Normal
CAUSE Malfunction of Membrane.
REMEDY Replace C/PANEL assembly.
20
(TROUBLE 8) When "Err 2" or "Err 3" come on display.
CONDITION
CHECK Check continuity of thermistor (resistance of thermistor)
RESULT 0 or infinite
CAUSE Defective thermistor
REMEDY Replace
"Err 2" or "Err 3" come on display
Approx 200k~300k (room temperature)
Check continuity of heater (upper, lower)
No continuty
Defective heater
Replace
continuity
Defective touch control circuit
Replace
21
9. MEASUREMENT AND TEST
9-1. 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. The water is contained in a cylindrical borosilicate glass vessel having a maximum material thickness of 3 mm and an outside diameter of approximately 190 mm. 3. The oven and the empty vessel are at ambient temperature prior to the start of the test. The initial temperature of the water is 10 ± 2°C (50 ± 3.6°F). If is measured immediately before the water is added to the vessel. After addition of the water to the vessel, the 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 heatup time for magnetron is not included. 6. The initial and final temperature of water is selected so that the maximum difference between the ambient and final water temperature is 5K. 7. The microwave power output P in watts is calculated from the following formula: P = 4187 X T/t · T is difference between initial and ending temperature. · t is the heating time. The power measured be B (Refer to SPECIFICATIONS) W ± 10.0 %.
CAUTION 1. Water load should be measured exactly to 1 liter. 2. Input power voltage should be exactly specified voltage (Refer to SPECIFICATIONS). 3. Ambient temperature should be 20 ± 2°C (68 ± 3.6°F)
Power level table Power level High Sauté Reheat Medium high Simmer percentage 100% (P-Hi) 90% (P-90) 80% (P-80) 70% (P-70) 60% (P-60) Output 800W 720W 630W 550W 470W Power level Medium Medium low Low Defrost Warm percentage 50% (P-50) 40% (P-40) 30% (P-30) 20% (P-10) 10% (P-10) Output 390W 300W 220W 140W 90W
22
9-2. 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. Care should be taken not to place the eyes in direct line with the source of microwave energy. 5. Slowly approach the unit under test until the radiometer reads an appreciable microwave leakage from the unit under the test.
PROCEDURE 1. Prepare Microwave Energy Survey Meter, 600cc glass beaker, and glass thermometer 100°C (212°F).
M/W Def. Grill Temp g
Auto Cook 1. Roast Beef 3. Roast Chicken 5. Vegetable 2. Roast Pork 4. Fish Fillets
2. Pour 275cc ± 15cc of tap water initially at 20 ± 5°C (68 ± 9°F) in the 600 cc glass beaker with an inside diameter of approx. 95 mm(3.5 in.). 3. Place it at the center of the tray and set it in a cavity. 4. Close the door and operate the oven. 5. Measure the leakage by using Microwave Energy Survey Meter with dual ranges, set to 2450MHz.
M/W
Defrost
Grill
1000g
10m.
Combi
100g
1m.
Temp
10s.
Clock
Auto Cook
Stop/ Clear
Start/ Speedy cook
Combi
KOC-621Q
1) Measured radiation leakage must not exceed the value prescribed below. Leakage for a fully assembled oven with door normally closed must be less than 4mW/Cm2. 2) When measuring the leakage, always use the 5 cm (2 in.) space cone with probe. Hold the probe perpendicular to the cabinet and door. Place the space cone of the probe on the door, cabinet, 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. from any metal. If it does not, erroneous reading may result.
23
9-3. 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. 1. High voltage transformer 1) Remove connections from the transformer terminals and check continuity. 2) Normal readings should be as follows : Secondary winding ... Approx. 100 ±10% Filament winding ... Approx. 0 Primary winding ... Approx. 1.2 2. High voltage capacitor 1) Check continuity of capacitor with meter on the highest OHM scale. 2) A normal capacitor will show continuity for a short time, and then indicate 10M once the capacitor charged. 3) A shorted capacitor will show continuous continuity. 4) An open capacitor will show constant 10M. 5) Resistance between each terminal and chassis should be infinite. 3. High voltage diode 1) Isolate the diode from the circuit by disconnecting the leads. 2) With the ohmmeter 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 should be used to check the front-back resistance of the diode, otherwise an infinite resistance may be read in both directions. A normal diode's resistance will be infinite in one direction and several hundred k in the other direction. 4. Magnetron For complete magnetron diagnosis, refer to "Measurement of the Microwave Power Output." Continuity checks can only indicate and open filament or a shorted magnetron. To diagnose for an open filament or a shorted magnetron, 1) Isolate magnetron from the circuit by disconnecting the leads. 2) A continuity check across magnetron filament terminals should indicate 0.1 or less. 3) A continuity check between each filament terminal and magnetron case should read open. 5. Fuse If the fuse in the primary and monitor switch circuit is blown when the door is opened, check the primary and monitor switch before replacing the blown fuse. In case the fuse is blown by an improper switch operation, replace the defective switch and fuse at the same time. Replace just the fuse if the switches operate normally.
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4. COMPONENT ACTION
COOKING MODE MANUAL MODE
M/W GRILL COMBI TEMP DEFROST
MAGNETRON q
UPPER ELEMENT LOWER ELEMENT
q q q q q q q q q q q q q q
AUTO COOK
ROAST BEEF ROAST PORK ROAST CHICKEN FISH FILLETS VEGETABLE
25
10. WIRING DIAGRAM
26
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
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NO A00 B00 F01 F02 F03 F04 F05 F06 F07 F08 F09 F10 F11 F12 F13 F14 F15 F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26 F27 F28 F29 F30 F31 F32 F33 F34 F35 F36 F37 F38 F39 F40 F41 F42 F43 F44 F45 F46 F47 F48 F49 F50 F51 F52 F53 F54 F55 F56 F57 F58 F59 F60 F61 F62 F63
PART NAME DOOR AS CONTROL-PANEL AS CABINET AS SCREW TAPPING SENSOR TEMPERATURE SCREW TAPPING SCREW TAPPING SCREW TAPPING SCREW TAPPING SCREW TAPPING CORD POWER AS NOISE-FILTER SCREW TAPPING SCREW TAPPING MOTOR SHADED POLE GUIDE WIND FAN NUT HEX SCREW TAPPING MAGNETRON SPECIAL SCREW SCREW TAPPING HEATER *U SUPPORTER HEATER *U SCREW TAPPING COVER HEATER *U SCREW TAPTITE HOLDER HV CAPACITOR CAPACITOR HV DIODE HV FUSE HV TRANS HV SPECIAL SCREW BASE FOOT SCREW TAPPING SCREW TAPTITE STOPPER HINGE *U AS HARNESS MAIN SW MICRO SW MICRO SW MICRO LEVER LOCK LOCK LAMP MOTOR SYNCRO SCREW TAPPING SCREW TAPTITE COVER WAVE GUIDE COUPLER GUIDE TRAY TRAY METAL TRAY RACK AS SCREW TAPPING THERMOSTAT SCREW TAPPING COVER INSULATOR *T SCREW TAPPING CLAMP WIRE HEATER SCREW TAPTITE GUIDE AIR OUTLET NUT HEX CAVITY JOINT AS REAR-PLATE *O
DESCRIPTION KOG-62150S KOC-621Q0S KOC-621Q0S T1 TRS 4*10 MFZN PTM-K312-D7 T1 TRS 4*10 MFZN T2S TRS 4*12 MFZN T1 TRS 4*10 MFZN T2S TRS 4*12 MFZN T1 TRS 4*10 MFZN 3X1.5 80X80 120-RTML 1.4M DWLF-M02 T1 TRS 4*10 MFZN T2S PAN 4X30 MFZN 230V 25W MW15CA-K01 PP 5113MF6 A353B P.P GF20 6N-2-5 MFZN T2S TRS 4*12 MFZN 2M218H(F) T2 FLANGE 4X13 PW SE M T1 BIN 4*8 MFNI 230V 400W R18374001 STS430 T0.5 T2S TRS 4*8 MFZN STS430-2B/HL T0.6 TT3 TRS 4X8 MFZN SECC T0.6 2100VAC 0.98UF #187 "HVR-1X-3AB 12KV #187" 5KV 0.7A HV-41A70-1 #187 DW-R80S0-62T TT3 HEX 4X8 FLG MFZN SBHG T0.8 DASF-310 T1 TRS 4*10 MFZN TT3 TRS 4X8 MFZN KOR-121M0A KOC-621Q0S VP-533A-OF SPNO #187 200G VP-531A-OF/SZM-V16-FA-61 VP-533A-OF SPNO #187 200G POM POM BL 240V 25W T25 C7A H187 100/240V 4W GM-16-24FD16 T2S PAN 4X10 MFZN TT3 TRS 4X8 MFZN MICA T0.35 PTFE SPP T1.0 SPP T0.6 KOC-621Q0S T2S PAN 3X6 MFZN OFF:145 ON:135 V #187 T1 TRS 4*10 MFZN SECC T0.5 T1 TRS 4*10 MFZN SBHG 230V 1150W 1B08965001 TT3 TRS 4X8 MFZN SA1D-80 T0.5 6N-2-5 MFZN KOC-621Q0S SBHG T0.6
PART CORD 3511709210 3516726550 3510806710 7112401011 3514801400 7112401011 7122401211 7112401011 7122401211 7112401011 35113A5QJ5 3518603710 7112401011 7121403011 3963512910 3512513700 3511800100 7392500011 7122401211 3518002200 3516002700 7113400814 3512802000 3515304000 7122400811 3511404410 7272400811 3513003200 3518302200 3518400400 3518700230 3518118710 3516003700 3510310800 3512101400 7112401011 7272400811 3515202800 3512718900 4415A17352 4415A66910 4415A17352 3513701300 3513807900 3513601600 3966030500 7121401011 7272400811 3511404710 3517401900 3512512810 3517205500 3517208400 7121300611 3518903200 7112401011 3511404500 7112401011 3511200400 3512803300 7272400811 3512513110 7392500011 3516107530 3516503700
Q'TY 1 1 1 3 1 1 1 4 2 1 1 1 1 2 1 1 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 4 1 4 5 2 1 1 1 1 2 1 1 1 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 2 1 1 1 1
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12. PRINTED CIRCUIT BOARD
CIRCUIT CHECK PROCEDURE
1. Low voltage transformer check The low voltage transformer is located on the P.C.B. Measuring condition: Input voltage: 230V / Frequency: 50Hz
3 4 6
Terminal 6-10
Voltage(olad) DC 13V
Voltage(no load) DC 14V
5
10 LVT1
DMR-621FS AS 230V/50Hz
NOTE 1. Secondary side voltage of the low voltage transformer changes in proportion to fluctuation of power source voltage. 2. The allowable tolerance of the secondary voltage is within ± 5% of nominal voltage.
2. Voltage Check - Key check point NO 1 2 CHECK POINT IC1 PIN 55, 64 IC1 PIN 17
5V 0V T
REMARK 5VDC±5%
T : 20 ms(50Hz)
3
IC1 PIN 30 OR 31
5V 0V T
T : 250 ns(4MHz)
- Check method NO 1 2 MEASURE POINT A B WAVE FORM DC 5V±5% DC 17V±20% REMEDY Replace C13, C3 Replace D10~D13, EC4 REMARK NO LOAD NO LOAD
NOTE: Each measure point must be measured with GND points.
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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.
B D2
1N4148
A
8
M/W RY1
G5G-1A-DT 12V
Q10 C106M
STATE RELAY 1 ON RELAY 1 OFF
POINT A +5V DC GND
POINT B GND +13V DC
2) When touching M/W button, oven lamp does not turn on and turntable motor does not rotate but cook indicator in display comes on. *Cause: RELAY 1 does not operate.
B A
16
LAMP, TRAY RY5
D15
1N4148 CS11-12SH 12V
Q7 C106M
STATE RELAY 5 ON RELAY 5 OFF
POINT A +5V DC GND
POINT B GND +13V DC
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.
B A
18
FAN RY6
D16
1N4148 CS11-12SH 12V
Q12 C106M
STATE RELAY 6 ON RELAY 6 OFF
POINT A +5V DC GND
POINT B GND +13V DC
30
4. Case of no heating of upper 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 3 does not operate.
B
A
14
UPPER GRILL RY3
D4
1N4148 G5G-1A-DT 12V
Q11 C106M
STATE RELAY 3 ON RELAY 3 OFF
POINT A +5V DC GND
POINT B GND +13V DC
5. Case of no heating 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.
B A
15
LOWER GRILL RY4
D14
1N4148 CS11-12SH- 12V
Q6 C106M
STATE RELAY 4 ON RELAY 4 OFF
POINT A +5V DC GND
POINT B GND +13V DC
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6. Case of no stopping of the count down timer When the door is opened during operation, the count down timer does not stop.
CN1
35313-0210
B
R1 1K
7
A
1 2 D.O.M SW
D1
1N4148
R4
10K
C1
104Z
+5V
POINT STATE DOOR OPEN DOOR CLOSED CHECK NO 1 A OPEN CLOSE B +5V DC GND REMEDY Replace door open monitor swith.
METHOD Check the stage(ON,OFF) of the door open monitor switch by resistance measurement.
32
13. P.C.B. CIRCUIT DIAGRAM
33
PCB ASS'Y PART LIST NO 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 NAME BUZZER CAPACITOR CERAMIC CAPACITOR CERAMIC C ARRAY CAPACITOR ELECTRO CAPACITOR ELECTRO CAPACITOR ELECTRO CONNECTOR WAFER CONNECTOR WAFER CONNECTOR WAFER CONNECTOR WAFER DIODE SWITCHING DIODE SWITCHING DIODE RECTIFYING DIODE ZENER LED DISPLAY IC MICOM REGULATOR PCB MAIN RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR ARRAY RESONATOR CERAMIC SW RELAY SW RELAY TRANSISTOR TRANSISTOR TRANSISTOR TRANSISTOR TRANS POWER WIRE COPPER 5mm WIRE COPPER 10mm WIRE COPPER12.5mm RESISTOR SYMBOL BZ1 C1,C3,C8,C9,C13 C11,C12 CA1 EC2 EC3 EC4 CN1 CN2 CN4 CN5 D2,D4,D14~D16 D1,D7,D8,D9 D5,D6,D10~D13 ZD2 DP1 IC1 VL1 M235 R4,R30,R36,R37 R1,R32,R34 R40 R38,R39 R5,R9,R17,R18 R31 R33 R10~R16 R41~R43 R6 R7 R8 RA1 CR1 RY1,RY3 RY4~RY6 Q8 Q15 Q1~Q5 Q6,Q7,Q10~Q13 LVT1 J1,J2,J6,J8,J9 J11~J13,J15.J19 J7,J14,J16~J18 J3,J4 SJ2 SPECIFCATION BM-20K 104 50V Z AXIAL 473 50V Z AXIAL 1000pF, 2.54MM 10V RSS 470uF 25V RSS 470uF 25V RSS 1000uF 35313-0210 35312-0310 FCZ254-8 35328-0610 1N4148 AUTO 52mm 1N4148M 5MM 1N4004A AUTO 52mm UZ -3.9BSB DDRG-621S-1 TMP87CK40ANMC7805C 81.5 X 214 1/6W 10K Ohm 5% 1/6W 1K Ohm 5% 1/6W 2K Ohm 5% 1/6W 4.7K Ohm 5% 1/6W 100K Ohm 5% 1/6W 1M Ohm 5% 1/6W 200 Ohm 5% 1/6W 330 Ohm 5% 1/2W 27 Ohm 5% 1/6W 5.88K Ohm 1% 1/6W 16.9K Ohm 1% 1/6W 1.30K Ohm 1% 5P(4) 1/8 100K 5% CRT-4.00MS G5G-1A-DT 12V CS11-12SH KTA1266Y AUTO KTC3198GR AUTO KRA106M AUTO KRC106M AUTO DMR-621FS 1/0.52 TIN COATING 1/0.52 TIN COATING 1/0.52 TIN COATING 1/6W 1K Ohm 5% PART CODE 3515600100 CCZF1H104Z CCZF1H473Z CN4XB-102M CEXF1A471V CEXF1E471V CEXF1E102V 30166M7020 30166M5030 441M367130 4CW3061MX0 DZN4148--DZN4148M-DZN4004A-DZUZ3R9BSB DDDRG621S1 13GS621Q00 1CPMC7805C 3514325200 RD-AZ103JRD-AZ102JRD-AZ202JRD-AZ472JRD-AZ104JRD-AZ105JRD-AZ201JRD-AZ331JRD-2Z270JS RN-AZ5881F RN-AZ1692F RN-AZ1301F RA-85X104J 5P4R00MTS5SC0101123 5SC0101128 TZTA1266YTZTC3198GR TZRA106M-TZRC106M-5EPV041412 85801052GY 85801052GY 85801052GY RD-AZ102JQ'TY 1 5 2 1 1 1 1 1 1 1 1 5 4 6 1 1 1 1 1 4 3 1 2 4 1 1 7 3 1 1 1 1 1 2 3 1 1 5 6 1 10 5 2 1
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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
S/M NO.:C621Q0S001
PRINTED DATE: DEC. 2001