DAEWOO KOC-924T9A Service Manual

Service Manual

Microwave Oven

Model: KOC-924T9A

S/M No. : C924T9A001

http : //svc.dwe.co.kr Feb. 2003

✔ 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).

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.

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.

TABLE OF CONTENTS

1. PROPER USE AND SERVICE PRECAUTIONS .........................................................................................................2

2. SPECIFICATIONS ........................................................................................................................................................3

3. EXTERNAL VIEW.........................................................................................................................................................4

3-1. OUTER DIMENSION ..........................................................................................................................................4

3-2. FEATURE DIAGRAM .........................................................................................................................................5

4. INSTALLATION ............................................................................................................................................................6

5. CONTROL PANEL .......................................................................................................................................................7

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

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

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

9. MESUREMENT AND TEST .......................................................................................................................................23

9-1. MEASUREMENT OF THE MICROWAVE POWER OUTPUT ........................................................................23

9-2. MICROWAVE RADIATION TEST ....................................................................................................................24

9-3. COMPONENT TEST PROCEDURE................................................................................................................25

9-4. COMPONENT ACTION....................................................................................................................................26

10. WIRING DIAGRAM...................................................................................................................................................27

11. EXPLODED VIEW AND PARTS LIST .....................................................................................................................29

11-1. DOOR ASSEMBLY.........................................................................................................................................29

11-2. CONTROL PANEL ASSEMBLY.....................................................................................................................29

11-3. TOTAL ASSEMBLY........................................................................................................................................29

12. PRINTED CIRCUIT BOARD ....................................................................................................................................32

13. P.C.B CIRCUIT DIAGRAM.......................................................................................................................................36

1. PROPER USE AND SERVICE 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 have excessive emission level 5mw/cm

, the service person should: (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 and CDRH immediately.

CAUTION

MICROWAVE RADIATION

PERSONNEL SHOULD NOT BE EXPOSED TO THE MICROWAVE ENERGY WHICH MAY RADIATE FROM THE MAGNETRON OR OTHER MICROWAVE GENERATING DEVICE IF IT IS IMPROPERLY USED OR CONNECTED. ALL INPUT AND OUTPUT MICROWAVE CONNECTIONS. WAVEGUIDE FLANGES AND PASKETS MUST BE SECURE. NEVER OPERATE THE DEVICE WITHOUT A MICROWAVE ENERGY ABSORBING LOAD ATTACHED. NEVER LOOK INTO AN OPEN SAVEGUIDE OR ANTENNA WHILE THE DEVICE IS ENERGIZED.

CAUTION

This device is to be Serviced only by Properly Qualified Service Personel. Consult the Service Manual for Proper Service Procedures to Assure Continued Safety Operation and for Precautions to be Taken to Avoid Possible Exposure to Excessive Microwave Energy.

2. SPECIFICATIONS

MODEL KOC-924T9A

POWER SUPPLY 230V~50HZ, SINGLE PHASE WITH EARTHING

MICROWAVE 1500W

POWER GRILL 1150W

CONSUMPTION CONVECTION 2550W

COMBINATION 3000W

MICROWAVE ENERGY OUTPUT 1000W(IEC705)

MICROWAVE FREQUENCY 2450MHz

OUTSIDE DIMENSIONS (W X H X D) 542X329X515mm (21.3X13.0X20.3 in.)

CAVITY DIMENSIONS (W X H X D) 350X230X355mm (13.8X9.1X14.0 in.)

NET WEIGHT APPROX. 20kg (44.1 lbs.)

TIMER 60 minutes

FUNCTION SELECTIONS MICROWAVE/ GRILL/ CONVECTION/ COMBINATION

POWER SELECTIONS 10 LEVELS

CAVITY VOLUME 1.0 Cu. Ft

* Specifications are subject to change without notice.

3. EXTERNAL VIEW

542

329

515

1. OUTER DIMENSION

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.

15.OVEN LAMP

Automatically turns on during oven operating.

16.SAFETY INTERLOCK SYSTEM

17.CONTROL PANEL

18.TURNTABLE TRAY

Rotates during cooking and ensure even distribution of Microwaves. It can also be used as a cooking utensil.

19.ROLLER GUIDE

This must always be used for cooking together with the turntable tray.

10. COUPLER

This fits over the shaft in the center of the ovens cavity floor. This is to remain in the oven for all cooking.

11. CONVECTION OUTLET & FAN

12. OVEN FRONT PLATE

13.DOOR SEAL

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

2. FEATURE DIAGRAM

1. Steady, flat location.

This microwave oven should be set on a steady, flat surface.

2. Leave space behind and side.

All air vents should be kept a clearance. If all vents are covered during operation, the oven may be overheated and, eventually, cause oven 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.

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 13 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 extension cord is used:

1) The marked electrical rating of the cord set or extension cord should be at least as great as the electrical rating of the appliance.

2) The extension cord must be a grounding type 3-wire cord.

3) The longer cord should be arranged so that it will not drape over the counter top or tabletop where it can be pulled on by children or tripped over unintentionally.

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.

4. INSTALLATION

5. CONTROL PANEL

Auto cook

MW Grill Combi Weight Time

Auto Cook

Lock

Convection

Defrost

Combi

Grill

Convection

START /

SPEEDY COOK

Weight Defrost

Auto Cook Menu

1. Roast pork

2. Roast beef

3. Roast chicken

4. Baked fish

5. Fresh vegetable

Time

Defrost

Clock

STOP/CLEAR

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. Time : When blinking, the oven is operating in TIME DEFROST. Auto-cook : When blinking, the oven is operating AUTO COOK. Lock : When lighting, the oven is CHILD LOCK. Con-vection : When blinking, the oven is operating in CONVECTION. lb : When blinking, the oven is operating in weight input mode.

Auto cook : Used to cook or reheat.

Combi : Used to select combi.

Weight Defrost : Used to defrost foods.

Grill : Used to select grill.

MW : Used to set power level of micro wave.

Time Defrost : Used to defrost foods.

Convection : Used to select convection and

selected temp.

Clock : Used to set clock.

Dial knob : Used to set time, weight and quantity.

START/SPEEDY COOK : Used to start a programmed, also for speedy start(each press adds 30 seconds microwave cooking time).

STOP/CLEAR : Used to stop the oven operation or to delete the cooking data.

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 20A 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.

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.

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 replacing the door assembly, perform a check

of correct alignment with the hinge and cavity front plate.

3. To remove door parts.

A10 A09 A08 A07

A06A05

A04

A03

A02

A01

A11

A12

A13

REF NO. PART CODE PART NAME DESCRIPTION Q’TY REMARK

A01 3512603620 HANDLE DOOR S455C 1

A02 3511608300 DECORATOR DOOR*R SUS430 T0.5 H/L 1

A03 3512204820 FRAME DOOR ALLOY PC+ABS 1

A04 7001503011 SCREW MACHINE PAN 5*30 MFZN 2

A05 3515101800 SPRING HOOK PW1 1

A06 3513101200 HOOK POM 1

A07 3512302400 GASKET DOOR PBT 1

A08 3516602200 DOOR PLATE SBHG-3A T0.7 1

A09 3515304800 SUPPORTER HINGE*T SCP-1 T2.0 1

A10 3517007000 BARRIER-SCREEN*I TEMP GLASS T2.0 1

A11 3511608700 DECORATOR DOOR*T SUS430 T0.5 H/L 1

A12 3511608400 DECORATOR DOOR*L SUS430 T0.5 H/L 1

A13 3511608200 DECORATOR DOOR*U SUS430 T0.5 H/L 1

✔ 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).

(1) Remove the gasket door from door plate. (2) Remove screws from door plate. (3) Remove the door frame from door plate. (4) Remove the stopper hinge top from door plate. (5) Remove the spring and the hook. (6) Remove the handle door and barrier screen outer from door frame. (7) 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.

NOTE : A small gap may be acceptable if the microwave leakage does not exceed 4mW/cm2.

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