Daewoo KOG-972T, KOG-985T2S Service Manual

S/M No. : C972T0S002

Service Manual

Microwave Oven

Model: KOC-972T0S

KOC-972T2S KOC-982T1S KOC-982T2S

KOC-983T1S KOC-983T2S KOC-984T1S KOC-984T2S

KOC-985T1S KOC-985T2S

DAEWOO ELECTRONICS CO., LTD.

PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO AVOID POSSIBLE EXPOSURE TO EXCESSI VE MICR OWAV E 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 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.

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.

(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.

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

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

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

1. OUTER DIMENSION..................................................................................................................... 4

2. FEATURE DIAGRAM................................................................................................................... 5

INSTALLATION................................................................................................................................... 7

EARTHING INSTRUCTIONS............................................................................................................... 7

CONTROL PAN E L .. ......... ... ......... ... ... ......... ... ......... ... ......... ... ... ......... ... ........ ... ......... ... ... .................... 8

DISASSEMBLY AND ASSEMBLY...................................................................................................... 9

INTERLOCK MECHANISM AND ADJUSTMENT............................................................................... 23

TROUBLE SHOOTING GUIDE .......... ... ......... ... .................. ... ......... ... ........ ... ... ......... ... ......... ... ........... 24

MEASUREMENT AND TEST............................................................... ................. ......... ......... ........... . 30

1. MEASUREMENT OF THE MICROWAVE POWER OUTPUT ...................................................... 30

2. ELECTRICAL CONTINUITY CHECK OF INTERLOCK SWITCH................................................. 31

3. MICROWAVE RADIATION TEST................................................................................................. 32

4. COMPONENT TEST PROCEDURE............................................................................................. 33

WIRING DIAGRAM.............................................................................................................................. 34

SCHEMATIC DIAGRAM...................................................................................................................... 35

EXPLODED VIEWS AND PARTS LIST.............................................................................................. 38

PRINTED WIRING BOARD................................................................................................................. 44

P.C.B. CIRCUIT DIAGRAM................................................................................ ......... ......... ............... 49

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SAFETY AND PRE CAUTIONS

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 m ains 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 w ith the coloured m arkings identifying the terminals in your plug, proceed as follows. The wire which is coloured green-and-yellow must be connected to the term inal 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 term inal w hich is marked with the letter 'L' or coloured red.

NOTE

This oven is designed for counter-top use only.

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SPECIFICATIONS

MOD EL KOC-972T0S KOC-972T2S POWER S U P P LY 230V~50Hz 230V~50Hz

MICROWAVE 1450W 1450W GRILL 1200W 1200W

POWER CONSUMPTION

MICRO WAVE ENER G Y OU TPUT 950W(IEC705) 950W(IEC705) MICRO WAVE FREQ UEN CY 2450MHz 2450MHz OUTS IDE DIMENSIONS (W X H X D) 526 x 345 x 413 mm (20.7 x 13.6 x 16.1 in.) CAVIT Y D IMENSIONS (W X H X D) 335 x 255 x 339 mm (13.2 x 10.0 x 13.3 in.) NET W E IGHT APPRO X. 20 Kg (44.2 lbs.) TIMER 60 minutes FUNCTION SELECTIONS MICROWAVE/G RILL/CONVECTION/COMBI POWER SELECTIONS 10 LEVELS CAVITY VOLUME 1.0 Cu.Ft.

CONVECTION 1550W 1550W PRO G R A M C O OK 1850W 1850W COM BINATION 2600W (Simultaneous) 1550W (Sequential)

MOD E L KOC -982T/983T/984T/985T1S KOC-982T/983T/984T/985T2S POWER S U P P LY 230V~50Hz 230V~50Hz

MICROWAVE 1450W 1450W GRILL 1200W 1200W

POWER CONSUMPTION

MICRO WAVE ENER G Y OU TPUT 1000W(IEC705) 1000W(IEC705) MICRO WAVE FREQ UEN CY 2450MHz 2450MHz OUTS IDE DIMENSIONS (W X H X D) 526 x 345 x 496 mm (20.7 x 13.6 x 19.5 in.) CAVIT Y D IMENSIONS (W X H X D) 335 x 250 x 339 mm (13.2 x 9.8 x 13.3 in.) NET W E IGHT APPRO X. 21 Kg (46.3 lbs.) TIMER 60 minutes FUNCTION SELECTIONS MICROWAVE/G RILL/CONVECTION/COMBI POWER SELECTIONS 10 LEVELS CAVITY VOLUME 1.0 Cu.Ft.

CONVECTION 1550W 1550W PRO G R A M C O OK 1850W 1850W COM BINATION 2600W (Simultaneous) 1550W (Sequential)

SPECIFICATIONS ARE SUBJECT TO CHANGE WITHOUT NOTICE.

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EXTERNAL VIEW

1. OUTER DIMENSION

KOC-972T

KOC-982T/983T/984T/ 985T

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2. FEATURE DIAGRAM

KOC-972T

EXTERNAL VIEW

Door seal

Door hook

the magnetron will immediately stop operating.

Door viewing screen

Top heater

Oven lamp

Safety interlock system

Control panel

Turntable tray

It can also be used as a cooking utensil.

Oven front plate

Rotating base

10.

This is to remain in the oven for all cooking. It should only be removed for cleaning.

Under heater

11.

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

- When the door is closed, it will automatically shut. If the door is opened while the oven is operating,

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

- Turns on when convection, grill and combi cooking is selected.

- Automatically turns on during oven operating.

- Rotates during cooking and ensure even distribution of Microwaves.

- This fits over the shaft in the center of the ovens cavity floor.

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EXTERNAL VIEW

KOC-982T/983T/984T/985T

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

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.

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

4. Top heater - Turns on when convection, grill and combi cooking is selected.

5. Oven lamp - Automatically turns on during oven operating.

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.

9. Oven front plate

10. Rotating base - This fits over the shaft in the center of the ovens cavity floor.

This is to remain in the oven for all cooking. It should only be removed for cleaning.

11. Under heater

12. Metal rack

13. Convection outlet & Fan

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 13amperes, 230 Volts, 50 Hz.

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 dam age 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 outle t that is properly installe d 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 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 acc e pt t h e p lu g o n 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.

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C ONTROL PANEL

When blinking, the oven is operating in "COMBI" cooking mode.

When blinking, the oven is operating in "GRILL" cooking mode.

When blinking, the oven is operating in "MICROWAVE" cooking mode.

When blinking, the oven is operating in "PROGRA M COOK" cooking mode.

When blinking, the oven is operating in "PIE" cooking mode.

When blinking, the oven is operating in "CONV ECTION" cooking mode.

Microwave Power Level-

Used to select the variable

microwave power level. If

this button(pad) is pressed for more than 1.3 sec, number is scrolled up au tomatically.

Dial Kn ob-

Used to input the cooking time and weight.

MW GRILL

PROGRAM

PIE

COOK

M/W

GRILL

COOK

DEFROST

COMBI

PROG RA M COOK

1.ROAST BEEF

2.ROAST PORK

3.ROAST CHICKEN

4.FISH FILLET

5.VEGETABLE

SPEEDY COOK

WEIGHT - TIMECOMBI

KGTEMP

DEFROST

TEMP

PIE

When blinking, the oven i s operating in "WEIGHT DEFROST" cooking mode.

When blinking, the oven i s operating in "TIME DEFROST" cooking mode.

When blinking, the oven i s operating in weght input mode.

Temperature Button(pad)-

Used to set desired temperature. If this button is pressed for more than

1.3 sec, number is scrolled up automatically.

Function Buttons(pads)-

Used to select desired cooki ng function.

M/W : MICROWAVE GRILL DEFROST : TIME or WEIGHT

DEFROST TEMP : CONVECTION COMBI : COMBINATION PIE PROGRAM COOK

Speedy Cook Button(pad)-

Used to program quickly cooking time in 30 sec increments.

Stop/ Cl ear Button-

Used to pause and clear all information man u ally put into the oven.

STOP/CLEAR

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START

(START/CLOCK)

Start Button-

Used to start the selected cooking cycle.

(KOC-972T)

Start/Clock Button-

Used to start the selected cooking cycle and to set time.

(KOC-982T/983T/984T/985T)

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. 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 make sure it is earthed properly before

beginning 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 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.

CAUTION

Service personnel should remove their watches whenever working close to or replacing 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 - HV Transformer, Magnetron, HV Capacitor, HV Diode.

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D ISASSE MBLY AN D A SSE M BLY

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.

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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.

D ISASSEMBLY AND ASSEMBLY

High voltage circuit wiring

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D ISASSE MBLY AN D A SSE M BLY

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 m etallic gas k e t p la te wh ic h is p ac k e d with e a c h magnetron to prevent microw ave leakage. Whenever repair work is carried out on m agnetron, check the microw ave leakage. It shall not

exceed 4mW /cm

for a fully assembled oven with door normally closed.

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6. To remove control panel assembly

KOC-972T, KOC-98 2T

(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 nine screws which secure the main and

sub PCB assembly to control panel. (3) Remove buttons and dial knob.

D ISASSEMBLY AND ASSEMBLY

REF NO. PART CODE PART NAME DESCRIPTION QTY REMARK

B01 3516715120 CONT RO L-PANEL A BS XR -401 1 B02 3515501210 WINDO W DISPLAY PMM A IF-850 1 B03 3516905100 BUTTON FUN CTION-A ABS XR -401 1 B04 3516906200 BUTTON FUN CTION-B ABS XR -401 1 B05 3513404600 KNOB VO LUM E ABS XR -401 1 B06 3516906300 BUTTON FUN CTION-C ABS XR-401 2 B07 PKBPM SP500 PCB SUB AS KOC-972T, K O C-982T 1 B08 7621301011 SC REW TAPPING T2S PAN 3x10 PW MFZ N 6 B09 PKMP M SQ300 PCB M AIN AS KOC-972T0S 1

PKMP M SQ300 PCB M AIN AS KOC-972T2S 1 PKMP M SQ350 PCB M AIN AS KOC-982T1S 1 PKMP M SQ350 PCB M AIN AS KOC-982T2S 1

B10 7621301011 SC REW TAPPING T2S PAN 3x10 PW MFZ N 3

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DISASSEMBLY AND ASSEMBLY

KOC-983T

(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 ten screws which secure the main and

sub PCB assembly to control panel. (3) Remove buttons. (4) Remove the knob volume.

REF NO. PART CODE PART NAME DESCRIPTION QTY REMARK

B01 3516719220 CONTROL-PANEL ABS XR-401 1 B02 3511603120 DECORATOR C-PANEL PET T0.2 1 B03 3513405200 KNOB VOLUME ABS XR-401 1 B04 3516906300 BUTTON FUNCTION ABS XR-401 1 B05 PKBPMSYB00 PCB SUB AS KOC-984T 1 B06 7621301011 SCREW TAPPING T2S PAN 3X10 PW MFZN 6

KOC-983T1S KOC-983T2S

B07 PKMPMSYB00 PCB MAIN AS B08 7122401211 SCREW TAPPING T2S TRS 4X12 MFZN 4

KOC-984T

(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. (3) Remove ten screws which secure the main and

sub PCB assembly to control panel. (4) Remove buttons. (5) Remove the decorator panel.

D ISASSEMBLY AND ASSEMBLY

REF NO. PART CODE PART NAME DESCRIPTIO N QTY REM ARK

B01 3516719200 CONT RO L-PANEL A BS XR -401 1 B02 3511602900 D ECO R ATOR C/P *T STS304 T0.6 H/L 1 B03 3511603000 D ECO R ATOR C/P *U STS304 T0.6 H/L 1 B04 3511603110 DECOR ATOR C-PA NE L PMM A IF-850 1 SMOG B05 3511602800 DE CO RATOR RING ABS XR -401 1 COATING B06 3513404620 KNOB VO LUM E ABS XR -401 1 CO ATING B07 3516905120 BUTTON FUN CTION ABS XR-401 1 CO ATING B08 3516907200 BUTTON FUN CTION ABS XR-401 1 CO ATING B09 3516906320 BUTTON FUN CTION ABS XR-401 2 CO ATING B10 PKBPM SYB00 PCB SUB AS KOC-984T 1

B11 7621301011 SCRE W TAPPING T2S PAN 3x10 PW MFZN 6 B12 PKMPMSYB00 PCB MAIN AS B13 7122401211 SC REW TAPPING T2S TR S 4x12 MFZN 4

KOC-984T1S KOC-984T2S

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