Daewoo KOG-39BG Service Manual

DAEWOOELECTRONICSCO.,LTD.

Service Manual

Microwave Oven

Model : KOG-37BG0S

KOG-39BG0S

DAEWOO ELECTRONICS CO., LTD

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

micro-wave 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 microwave power for any service test or inspection within the microwave generating

com-partments, 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.

(e) A microwave leakage check to verify compliance with the Federal Performance Standard should be

performed on each oven prior to release to the owner.

T ABLE OF CONTENTS

SAFETY AND PRECAUTIONS .......................................................................................................................................2

1. FOR SAFE OPERATION.........................................................................................................................................2

2. FOR SAFE SERVICE PROCEDURES....................................................................................................................2

SPECIFICATIONS................................................................................................................. ...........................................3

EXTERNAL VIEW ............................................................................................................................................................3

1. OUTER DIMENSION................................................................................................................................................3

2. FEATURE DIAGRAM...............................................................................................................................................4

3. CONTROL PANEL...................................................................................................................................................5

INSTALLATION................................................................................................................................................................6

OPERATION AND FUNCTIONS .....................................................................................................................................7

DISASSEMBLY AND ASSEMBLY..................................................................................................................................8

INTERLOCK MECHANISM AND ADJUSTMENT ........................................................................................................17

TROUBLE SHOOTING GUIDE......................................................................................................................................18

MEASUREMENT AND TEST ........................................................................................................................................22

1. MEASUREMENT OF THE MICROWAVE POWER OUTPUT..............................................................................22

2. MICROWAVE RADIATION TEST..........................................................................................................................23

3. COMPONENT TEST PROCEDURE .................................................................................................... .................24

WIRING DIAGRAM ........................................................................................................................................................25

PRINTED CIRCUIT BOARD..........................................................................................................................................26

1. CIRCUIT CHECK PROCEDURE...........................................................................................................................26

2. PCB CIRCUIT DIAGRAM.......................................................................................................................................29

3. P.C.B. LOCATION NO .......................................................................................................... .................................30

EXPLODED VIEW AND PARTS LIST...........................................................................................................................32

1. DOOR ASSEMBLY ............................................................................................................... .................................32

2. CONTROL PANEL ASSEMBLY ............................................................................................................................32

3. TOTAL ASSEMBLY................................................................................................................................................32

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.

(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, the service person should tell the user not to operate the oven and contact the manufacturer immediately.

important

The wires 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 the the terminal in the plug which is marked with the letter ‘E’ or by earth symbol or 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.

MODEL KOG-37BG KOG-39BG POWER SUPPLY 230V-50Hz, SINGLE PHASE WITH EARTHING POWER MICROWAVE 1200W 1350W CONSUMPTION GRILL 1050W 1050W

COMBINATION 2200W 2350W MICROWAVE ENERGY OUTPUT 800W 900W MICROWAVE FREQUENCY 2450MHz OUTSIDE DIMENSIONS (W X H X D)

465x279x356mm (18.3x11.0x14.0 in.) 495x294x384mm (19.5x11.6x15.1 in.) CAVITY DIMENSIONS (W X H X D) 290x220x306mm (11.4x8.7x12.0 in.) 320x244x338mm (12.6x9.6x13.3 in.) NET WEIGHT APPROX. 13.7Kg (30.2 lbs.) APPROX. 15.8Kg (34.9 lbs) TIMER 59 min. 90 sec. FUNCTION SELECTIONS MICROWAVE POWER SELECTIONS 10 LEVELS CAVITY VOLUME 0.7 Cu.Ft. 0.9 Cu.Ft.

* SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE.

1. OUTER DIMENSION

465/495 356/384

279/294

SPECIFICATIONS

EXTERNAL VIEWS

1 2 3 4 5

890qw

1. Door seal - Door seal maintains the microwave energy within the oven cavity and prevents microwave leakage.

2. Reflector (Insulator Heater)

3. Heating Element

4. Oven cavity

5. Safety interlock system

6. Door release button - By pushing this button the latch

system cut off all circuits and stops the oven before the door is opened.

7. Metal Rack

8. Coupler - This fits over the shaft in the center of the

ovens cavity floor. This is to remain in the oven for all cooking.

9. Roller guide - This must always be used for cooking together with the glass cooking tray.

10. Glass cooking tray - Made of special heat resistant gkass. Food in a proper receptacle is placed on this tray for cooking.

11. Door viewing screen - Allows viewing of food. The screen is designed so that light can pass through, but not the microwave.

12. Door hook - When the door is closed, it will automatically shut off. If the door is opened while the oven is operating, the magnetron will immediately stop operating.

2. FEATURE DIAGRAM

M/W Def. Grill Combi Timer/g

Pasta

1. BREAD

2. SOUP

3. BAKED POTATO

4. FRESH VEGETABLE

5. FROZEN VEGETABLE

Auto

Cook

Frozen Pizza

Auto Defrost

Fish Poultry Meat

1min

10s

10min

1hour

10m

STOP/ CLEAR

START/

SPEEDY COOK

Beverage

GRILL DefrostCOMBI

Kitchen

Timer

ClockPower



13. Time set pad - Used to set the cooking time and the present time.

14. Display - Cooking time, power level, indicators and present time are displayed.

15. One touch - Used to cook or reheat specific quantities of food.

16. Auto Cook - Used to cook or reheat.

17. More - Used to add time to cooking.

18. Less - Used to remove time from cooking.

19. Auto Defrost - Used to defrost foods. (for weight)

20. Combi - used to cook COMBI.

21. Grill -Used to cook GRILL.

22. Power - Used to set power level.

23. Defrost - Used to defrost foods. (for time)

24. Kitchen Timer - Used as a minute timer, to deelay

the start of cooking, or to set a holding time after cooking.

25. Clock - Used to set clock.

26. Stop/Clear - Used to stop the oven operation or to

delete the cooking data.

27. Start/Speedy cook - Used to start the oven and also used to set a reheat time.

3. FEATURES DIAGRAM (CONTINUED)

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 shouls 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 possinle.

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 11 amperes, 220~240 Volts, 50Hz.

• Power supply cord is about 0.8 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 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.

INSTALLATION

EARTHING INSTRUCTIONS

This appliance must be earthed. In the event od 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 or serviceman if the earthing instruction 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.

1. Connect the mains lead to an electrical socket-outlet.

2. After placing the food in a suitable utensil, open the oven door and put it on the glass turntable, Glass turntable must always be in place during cooking.

3. Close the door securely.

4. When the oven door is opened, the light turns off.

5. The oven door can be opened at any time during operation by touching the door release button on the control panel. The oven will automatically shut off. To restart the oven, close the door and then touch START.

6. Each time a pad is touched, a BEEF will sound to acknowledge the touch.

7. The oven automatically cook on full power unless set to a lower power level.

8. The display will show : 0 when the oven is plugged in.

9. Time clock returns to the present time when the cooking time ends.

10. When the STOP/CLEAR pad is touched during the oven operation, the oven stops cooking and all information retained. To erase all information (except the present time), touch the STOP/CLEAR pad once more. If the oven door is opened during the oven operation, all information is retained.

11. If the START pad is touched and the oven does not operate, check the area between the door and door is closed securely. The oven will not start cooking under the door is completely closed or the program has been reset.

12. When using the GRILL or COMBI mode ;

• Do not open the door so often, the temperature inside the oven decrease and the cooking may not complete in

setting time.

• Never touch the oven window and metal interior of the oven when taking food in and out, because of the

temperature inside the oven and door is very high.

• When using these modes, be careful as the tray will be hot to touch, use oven gloves or pot holders while

handling tray.

Wattage output chart

The power level is set by pressing the Power pad. The chart shows the display, the power level and the percentage of power.

OPERATIONS AND FUNCTIONS

Make sure the oven is properly installed and plugged into the electrical outlet.

Touch Power pad. Power level (Display) Approximate Percentage of Power

One P-HI 100 %

Twice P-90 90 % 3 times P-80 80 % 4 times P-70 70 % 5 times P-60 60 % 6 times P-50 50 % 7 times P-40 40 % 8 times P-30 30 % 9 times P-20 20 %

10 times P-10 10 % 11 times P-00 0 %

Cautions to be observed when trouble shooting.

Unlike many other appliances, the microwave oven is a 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. Use an insulated screwdriver and ware rubber gloves when servicing the high voltage side.

3. Discharge the high voltage capacitor before touching any oven components or wiring. (1) Check the earthed.

Do not operate on a two wire extension cord. The microwave oven is designed to be used with earthed. It is imperative, therefore, to makes sure it is earthed properly before begining 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 insulted screw driver to discharge.

4. When the 15A fuse is blown out due to the operation of the monitor switch; replace primary, secondary interlock switch and monitor switch. Refer to next page for the necessary adjustment.

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 repairing the

magnetron.

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

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

DISASSEMBLY AND ASSEMBL Y

1. To remove cabinet.

1) Remove three screws on cabinet back.

2) Push the cabinet backward.

2. To remove door assembly.

1) Remove a screw which secure the stopper hinge top.

2) Remove the door assembly from top plate of cavity

3) Reverse the above for reassembly.

NOTE

After replacing the door assembly, perform a check of correct alignment with the hinge and cavity front plate.

3. To remove door parts

(1) KOG-37BG0S

REF.NO PART CODE PART NAME DESCRIPTION QTY REMARK

A01 3512202070 FRAME DOOR ABS XR-401 H-2938 1 A02 3517003050 BARRIER-SCREEN*O ACRYL 1 A03 3515304610 SUPPORTER BARR-S*O PP 1 A04 3515204100 STOPPER HINGE *T AS KOR-6315OS 1 A05 3511705500 DOOR WELD AS KOR-6115OS 1 A06 3517002800 BARRIER-SCREEN *I POLYESTER T0.1 1 A07 3512300200 GASKET DOOR PP 1 A08 3513100700 HOOK POM 1 A09 3515101300 SPRING HOOK PW1 1

(2) KOG-39BG0S

REF.NO PART CODE PART NAME DESCRIPTION QTY REMARK

A01 3512202270 FRAME DOOR ABS XR-401 H-2938 1 A02 3517003150 BARRIER-SCREEN*O ACRYL 1 A03 3515304410 SUPPORTER BARR-S*O PP 1 A04 3515204100 STOPPER HINGE *T AS KOR-6315OS 1 A05 3511711900 DOOR WELD AS KOR-866T1S 1 A06 3517006000 BARRIER-SCREEN *I POLYESTER T0.1 1 A07 3512302000 GASKET DOOR PP 1 A08 3513100700 HOOK POM 1 A09 3515101300 SPRING HOOK PW1 1

DOOR ASSEMBLY KOG-37BG0S: 3511710330 KOG-39BG0S: 3511710710

(1) Remove the gasket door from door weld as. (2) Remove the barrier screen inner from door weld as. (3) Remove the door frame from door weld as. (4) Remove the stopper hinge top from door weld as. (5) Remove the spring and the hook. (6) Remove the supporter barrier screen outer from door frame. (7) Remove the barrier screen outer from door frame. (8) 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 three screws on bottom hinge, and then the door to contact the door seal to oven front surface.

• Tighten three screws.

NOTE: A small gap may be acceptable if the microwave leakage does not exceed 4m W/cm

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