Daewoo KOC-995T0S Service Manual

S/M No. : C995T0S110

Service Manual

Microwave Oven

Model: KOC-995T0S
KOC-995T0S11

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 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.

(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.

(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.

TABLE OF CONTENTS

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

SPECIFICATIONS 3
EXTERNAL VIEW 4

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

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

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

CONTROL PANEL .............................................................................................................................. 8

DISASSEMBLY AND ASSEMBLY...................................................................................................... 10

INTERLOCK MECHANISM AND ADJUSTMENT............................................................................... 20

TROUBLE SHOOTING GUIDE ........................................................................................................... 21

MEASUREMENT AND TEST.............................................................................................................. 27

1. MEASUREMENT OF THE MICROWAVE POWER OUTPUT ...................................................... 27

2. ELECTRICAL CONTINUITY CHECK OF INTERLOCK SWITCH................................................. 28

3. MICROWAVE RADIATION TEST................................................................................................. 29

4. COMPONENT TEST PROCEDURE............................................................................................. 30

WIRING DIAGRAM.............................................................................................................................. 31

SCHEMATIC DIAGRAM...................................................................................................................... 32

EXPLODED VIEW AND PARTS LIST................................................................................................. 35

PRINTED WIRING BOARD................................................................................................................. 41

P.C.B. CIRCUIT DIAGRAM................................................................................................................. 46

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

SPECIFICATIONS

MODEL KOC-995T0S KOC-995T0S11

POWER SUPPLY 230V~50Hz 230V~50Hz

MICROWAVE 1,550W 1,550W

POWER
CONSUMPTION

MICROWAVE ENERGY OUTPUT 1,000W(IEC705) 1,000W(IEC705)
MICROWAVE FREQUENCY 2,450MHz 2,450MHz
OUTSIDE DIMENSIONS (W X H X D) 526 x 345 x 496 mm (20.7 x 13.6 x 19.1 in.)
CAVITY DIMENSIONS (W X H X D) 335 x 260 x 335 mm (13.2 x 10.2 x 13.2 in.)
NET WEIGHT APPROX. 23.0 Kg (50.8 lbs.)
TIMER 60 minutes

FUNCTION SELECTIONS
POWER SELECTIONS 10 LEVELS

CAVITY VOLUME 1.0 Cu.Ft.

GRILL 1,400W 1,400W
CONVECTION 1,450W ( Temporary Maximum Power Consumption : 2,800W )
COMBINATION 2,950W (Simultaneous) 1,550W (Sequentional)

MICROWAVE/GRILL/CONVECTION/COMBI/

ROTISSERIE(option)

* SPECIFICATIONS ARE SUBJECT TO CHANGE WITHOUT NOTICE.

3

EXTERNAL VIEW

1. OUTER DIMENSION

4

2. FEATURE DIAGRAM

2-1. KOC-995T0S

EXTERNAL VIEW

1. Door seal -

2. Door hook

magnetron will immediately stop operating.

3. Door viewing screen -

microwave.

4. Top heater -

5. Oven lamp

6. Safety interlock system

7. Control panel

8. Turntable tray -

9. Oven front plate

10. Rotating base -

cooking. It should only be removed for cleaning.

11. Metal rack

12. Convection outlet & Fan

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

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

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

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.

It can also be used as a cooking utensil.

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

microwave leakage.

5

EXTERNAL VIEW

2-2. KOC-995T0S11

1. Door seal -

2. Door hook -

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

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

5. Oven lamp

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

12. Convection outlet & Fan

13. Guide Rotary

14. Motor Synchro

15. Utensil Bar

microwave leakage.

6

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 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 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 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.

7

CONTROL PANEL

1. KOC-995T0S

8

2. KOC-995T0S11

CONTROL PANEL

9

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 makes 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.

10

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.

10

DISASSEMBLY AND ASSEMBLY

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.

* High voltage circuit wiring

12

DISASSEMBLY AND ASSEMBLY

5. To temove guide air assembly

1) Remove two screws holding guide air assembly
to the oven cavity.

2) Remove a screw which secure the lamp to guide
air assembly.

3) Remove lever damper to valve damper.

4) Remove a screw which secure the solenoid to
guide air assembly.

5) Reverse the above steps for reassembly.

REF CO. PART CODE PART NAME DESCRIPTION QTY REMARK

1 3512508000 GUIDE AIR WELD AS KOC-961C0S 1
2 3515400200 VALVE DAMPER SBHG-1 T0.5 1
3 3517501000 PROTECTOR DAMPER SILICON RUBBER 1
4 3519000100 SOLENOID DC DET-SL-007 DC12V 1
5 7142400611 SCREW TAPPING
6 3513700300 LEVER DAMPER SUS 304 H DIA :0.8 1
7 3515101000 SPRING DAMPER HSWR 1
8 3513601000 LAMP BM 240V 25W T25 1

9 7112401011 SCREW TAPPING
10 441Z724041 SHAFT DAMPER SWRM 1
11 7112401011 SCREW TAPPING
12 441Q523060 FIXTURE SOLENOID SWC PI1.0 1

T2 TRS 456 MFZN

T1 TRS 4510 MFZN

T1 TRS 4510 MFZN

1

1

2

13

DISASSEMBLY AND ASSEMBLY

6. To remove convection part

1) Remove four screws holding guide air
assembly to the oven cavity.

2) Remove a special screw to convection part.

3) Remove the fan convection.

4) Remove the pipe.

5) Remove three screws which hold the heater
to convection part.

6) Remove the heater to convection part.

7) Remove the cover reflector to convection part.

8) Remove the insulator to the convection part.

9) Remove four screws which secure cover insulator to the bracket motor shaded.

10) Remove the cover insulator to the convection part.

11) Remove the fan to the convection part.

12) Remove two screws which secure the motor shaded pole to the bracket motor shaded.

13) Remove the screw which secure the thermostat to the bracket motor.

14) Reverse the above steps for reassembly.

REF CO. PART CODE PART NAME DESCRIPTION QTY REMARK

1 3963513700 MOTOR SHADED POLE 230V 50HZ OEM-10DWC2-C07 1
2 7S312X4081 SCREW TAPPING
3 3510601500 BRACKET MOTOR SHADED SBHG-1 T0.8 1
4 7051400811 SCREW MACHINE
5 441B629071 FAN SA1D-80 T0.5 1
6 3511404000 COVER INSULATOR SA1D-80 T0.7 1
7 3513301600 INSULATOR *B CERAMIC BLANKET T0.6 1
8 3511404100 COVER REFLECTOR SA1D-80 T0.7 1

9 3514400410 PIPE A1100BR 1
10 3513002300 HOLDER HEATER SUS304 T0.5 3
11 7121400811 SCREW TAPPING
12 7S627W40X1 SPECIAL SCREW NUT FLANGE M4 MFZN 1
13 3511800400 FAN CONVECTION SA1D-80 T0.5 1
14 3512801800 HEATER 230V 1400W 1R18344 1
15 7112401011 SCREW TAPPING
16 3518903800 THERMOSTAT OFF:160 ON:115 V#187 1
17 7121400811 SCREW TAPPING

T1 TRS 458 SE MFZN

PAN 458 SW MFZN

T2S PAN 458 MFZN

T1 TRS 4510 MFZN

T2S PAN 458 MFZN

4

2

5

4

1

14

7. To remove magnetron

WARNING

1) Remove three screws which secure the magnetron.

2) Remove the magnetron.

3) Reverse the above steps for reassembly.

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.

14

DISASSEMBLY AND ASSEMBLY

8. To remove control panel assembly

(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 window display.

REF CO. PART CODE PART NAME DESCRIPTION QTY REMARK

B01 3516719230 CONTROL-PANEL PC 1
B02 3511603100 DECORATOR C-PANEL STS304 T0.6 H/L 1
B03 3515501400 WINDOW DISPLAY PMMA IF-850 1 SMOG
B04 3513404620 KNOB VOLUME ABS XR-401 1 COATING
B05 3516905120 BUTTON FUNCTION ABS XR-401 1 COATING
B06 3516907200 BUTTON FUNCTION ABS XR-401 1 COATING
B07 3516906320 BUTTON FUNCTION ABS XR-401 2 COATING
B08 3514321800 PCB SUB AS KOC-995T0S 1
B09 7621301011 SCREW TAPPING T2S PAN 3x10 PW MFZN 6

B10

B11 7122401211 SCREW TAPPING T2S TRS 4x12 MFZN 4

3514312810 PCB MAIN AS KOC-995T0S 1
3514320330 PCB MAIN AS KOC-995T0S11 1

16

DISASSEMBLY AND ASSEMBLY

9. 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 steps for reassembly.

NOTE

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

10. To remove door parts

(1) Remove the gasket door. (4) Remove the barrier-screen *o.
(2) Remove the door seal assy. (5) Remove two screws.
(3) Remove the hook and spring. (6) Remove the handle from the frame door.

REF. NO. PART CODE PART NAME DESCRIPTION QTY REMARK

A01 3511708400 DOOR SEAL AS KOC-971C0S 1
A02 3513101100 HOOK POM 1
A03 3515101300 SPRING HOOK PW1 1
A04 3517004080 BARRIER-SCREEN *O TEMPERED GL T3.2 1 MIRROR
A05 3512204020 FRAME DOOR PC 1
A06 3511603200 DECORATOR DOOR *T STS304 T0.6 H/L 1
A07 3511603300 DECORATOR DOOR *U STS304 T0.6 H/L 1
A08 3515203610 STOPPER HINGE *T AS KOC-995T0S 1
A09 3512602410 HANDLE DOOR *T AS ABS XR-401 SILVER 1 KOC-985T
A10 3512602300 HANDLE DOOR *U ABS XR-401 1
A11 7121300811 SCREW TAPPING T2S PAN 3x8 MFZN 1
A12 7121400811 SCREW TAPPING T2S PAN 4x8 MFZN 1
A13 3512300800 GASKET DOOR PBT 1

17

DISASSEMBLY AND ASSEMBLY

11. 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.

(3) To reduce gap located on part ‘C’

•

Loosen a screw on interlock switch assembly

located bottom of oven body.

•

Draw the interlock switch assembly inward as possible to engage with hook on the door bottom.

•

Tighten a screw.

(4) To reduce gap located on part ‘D’

•

Loosen a screw on interlock switch assembly located top of oven body.

•

Following steps are same as step (3).

NOTE

Small gap may be acceptable if the microwave leakage does not exceed 1mW/cm

2

.

NOTE

The door on a microwave oven is designed to act as an electronic seal preventing the leakage of microwave energy
from the oven cavity during the cook cycle. This function does not require that the door be air-tight, moisture (conden­sation) Tight or light-tight. Therefore, the occasional appearance of moisture, light or the sensing of gentle warm air
movement around the oven door is not abnormal and do not of themselves, indicate a leakage of microwave energy
from the oven cavity. If such were the case, your oven could not be equipped with a bent, the very purpose of which
is to exhaust the vapor-laden air from the oven cavity.

18

13. To remove tray motor

1) Cut the tray motor cover parts from
the base plate.

2) Remove two screws which secure
the tray motor.

14. To remove grill heater assembly

1) Release two hex nuts holding the Grill Heater Assembly to top and side plate.

2) Remove Grill Heater Assembly.

.

18

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, door open monitor switch and interlock monitor switch
When the door is closed, the hook pushes the latch lever downward.
The latch lever presses the button of the interlock monitor switch to bring it under “OFF” condition and
presses the button of the secondary interlock switch and door open monitor 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
(1) Loosen two mounting screws.
(2) Adjust interlock switch assembly position.
(3) Make sure that latch lever moves smoothly after adjustment is completed.
(4) 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.

20

TROUBLE SHOOTING GUIDE

CONDITION

Continuity

0 infinite

Approx.

(normal)

Fuse again

Replace

Replace

Replace

Replace

Replace

Malfunction

Malfunction

of interlock

Shorted

contacts of

Defective

high voltage

Following the procedures below to check if the oven is defective or not.

1. Check grounding before checking trouble.

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 transformer, disconnect one lead wire from these parts
and then 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 into the wall outlet.
Check wire harness, wiring, and connected of the terminals and power cord before check parts listed below.

(TROUBLE 1) Oven does not operate at all; any inputs can not be accepted.

CHECK RESULT CAUSE REMEDY

Fuse blows.

Check continuity of

interlock monitor switch

with door closed

(COM NC)¡ê

Check continuity of both

primary and secondary

interlock switch with

door closed

Check continuity of

primary interlock switch

contact with door

partially open until

interlock monitor switch

contact close

(COM NC close)¡ê

Check continuity of

primary winding of low

voltage transformer

(COM NC)¡ê

Continuity

(COM NC)¡ê

No Continuity

Continuity

Continuity

Ω

150~210

of interlock

monitor

switch

No

switch

primary

interlock

switch

or

Defective low

voltage

transformer

NOTE 1

NOTE 1

NOTE 1

Disconnect high voltage

fuse and operate the unit

blows

transformer

21

TROUBLE SHOOTING GUIDE

CONDITION

Defective

supply cord

Defective

Replace

Adjust

Adjust

CONDITION

Malfunction

Defective

Faulty

contacts of

Defective

Adjust or

Adjust or

Replace

Replace

Replace

No

Continuity

0 V

CHECK RESULT CAUSE REMEDY

Outlet has
proper voltage
Fuse does not

blow.

Check continuity of noise

Check continuity of

magnetron

filter board

Check continuity of

power supply cord

No

Continuity

No

Continuity

No

Continuity

Normal

Defective

magnetron

noise filter board

Open power

touch control

NOTE

All these switches must be replaced at the same time, please refer to (7.Interlock Mechanism and Adjust)
for adjustment instructions.

(TROUBLE 2) Grill heater (top heater) is not heated; Food will not become hot.

Replace

circuit

CHECK RESULT CAUSE REMEDY

Grill heater is

not heated.

Check continuity of

primary interlock switch

Check continuity of

secondary interlock switch

Check continuity of

heater

Check D.C. voltage

being supplied to

RELAY (RY2) coil

No

Continuity

No

Continuity

Approx

12 VDC

Malfunction

of primary

interlock switch

of secondary

interlock switch

heater

touch control

circuit

RELAY

(RY2) or open

relay coil

Replace

Replace

22

(TROUBLE 3) No microwave oscillation even though fan motor rotates.

CONDITION

Continuity

0 or

No

Continuity

No

Continuity

0 V

Approx

12 VDC

Defective

high voltage

Defective

high voltage

Defective

magnetron

Defective

magnetron

Defective

high voltage

Defective

high voltage

Defective

Faulty

contacts of

Replace

Replace

Replace

Replace

Replace

Replace

Replace

Replace

Check continuity of high

Check continuity of high

Check continuity of high

TROUBLE SHOOTING GUIDE

No microwave

oscillation

terminals with wires

forward and backward

Connect megger leads to

magnetron terminal and

CHECK RESULT

No

voltage fuse

Replace high voltage fuse

Continuity

Continuity

voltage capacitor

removed

Continuity in

voltage rectifier in

backward

direction

direction with DC

megger

magnetron body

CAUSE

transformer

rectifier

REMEDY

Check resistance of

primary and secondary

coil of high voltage

transformer

Check continuity of

magnetron with wires

removed

Check continuity of

filament terminal of high

voltage transformer

Check D.C. voltage

being supplied to

RELAY (RY1) coil

Ω

¡Ä

transformer

transformer

touch control

circuit

RELAY

(RY1) or open

relay coil

23

TROUBLE SHOOTING GUIDE

CONDITION

Adjust or

Adjust or

Replace

Replace

Malfunction

0 V

Approx.

Malfunction

Defective

Faulty

contacts of

CONDITION

Adjust or

Adjust or

Replace

Replace

Malfunction

0 V

Approx.

Malfunction

Defective

Faulty

contacts of

Replace

(TROUBLE 4) Display shows all figures selected, but oven does not start cooking, even though desired program and time are

set and start pad is tapped.

CHECK RESULT CAUSE REMEDY

1) Turn table
motor and

Check continuity of

primary interlock switch

No

Continuity

oven lamp do

not turn on

2) Rotisserie

motor do

not rotate.

Check continuity of

secondary interlock and

No

Continuity

D.O.M. switch

Check D.C. voltage

being supplied to

RELAY (RY3) coil

12 VDC

(TROUBLE 5) 1) Under heater is not heated; Food will not become hot.

2) Convection motor does not rotate.

of primary

replace

interlock

switch

of secondary

replace

interlock and

D.O.M. switch

touch control

circuit

RELAY

(RY3) or open

relay coil

1) Under heater
is not heated.

2) Convection

fan and motor

does not rotate.

CHECK RESULT CAUSE REMEDY

Check continuity of

primary interlock switch

Check continuity of

secondary interlock switch

Check continuity of

heater (motor)

Check D.C. voltage

being supplied to

RELAY (RY5) coil

No

Continuity

No

Continuity

No

Continuity

12 VDC

of primary

interlock

switch

of secondary

interlock switch

Defective

heater(motor)

touch control

circuit

RELAY

(RY5) or open

relay coil

replace

replace

24

TROUBLE SHOOTING GUIDE

CONDITION

Replace

control box

sub-assembly

Replace

the button

Malfunction

Malfunction

(TROUBLE 6) The following visual conditions indicate a probable defective touch control circuit or button P.C.B. assembly.

1. Incomplete segments
(1) Segments missing
(2) Partial segments missing
(3) Digit flickering other than normal fluorescent slight flickering
(4) 0 does not display when power is on.

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 indicates a number different from one touched.
(for example, even if one touched 5, 3 appears in the display.

5. Specific numbers (for example, 2 or 3) do not display
when the button is touched.

6. Display does not count down or up with time cooking or
clock operation.

7. Oven is programable and cooks normally but no display shows.

8. Display obviously jumps in time while counting down.

9. Display counts down noticeably too fast while cooking.

10. Display does not show the time of day when clear button is touched.

11. Oven lamp and turntable motor do not stop although cooking is finished.
Check if the RELAY (RY3) contacts close and if they are close, replace touch control circuit.

CHECK RESULT CAUSE REMEDY

Display does

not show
programming
at all, even if

keyboard is

touched.

Check each button for

continuity of the button

keyboard for the

following keyboard

check procedure

Normal

of touch
control circuit
of control box

sub-assembly

Normal

of botton

keyboard

NOTE

Before following the particular steps listed above in the trouble shooting guide for the button keyboard’s failure,
please check for the continuity of each wire-harness between the button keyboard and P.C.B. assembly.

keyboard

25

TROUBLE SHOOTING GUIDE

BUTTON KEYBOARD CHECK PROCEDURE

1. Type of button names

( key metrix and circuit diagram )

The tact switch keyboard consists of 10 keys which configurations are described above.

2. Key check procedure
To determine if the tact switch keyboard is defective or not, check the continuity of each button(key) contacts with a
multimeter.

1) PROGRAM COOK button : between 4 and 15

2) TIME DEFROST button : between 8 and 14 (KOC-995T0S)
/ DEFROST button : between 8 and 14 (KOC-995T0S11)

3) COMBI button : between 6 and 15

4) GRILL button : between 8 and 12

5) M/W button : between 8 and 15

6) WEIGHT DEFROST button : between 8 and 10 (KOC-995T0S)

/ ROTISSERIE button : between 8 and 10 (KOC-995T0S11)

7) SPEEDY COOK button : between 6 and 10

8) TEMP button : between 6 and 14

9) START/CLOCK button : between 2 and 12

10) STOP/CLEAR button : between 2 and 14

26

MEASUREMENT AND TEST

1. MEASUREMENT OF THE MICROWAVE POWER OUTPUT

Microwave output power can be checked by indirectly measuring the temperature rise of a certain
amount of water exposed to the microwave as directed below.

PROCEDURE

1. Microwave power output measurement is made wit 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).
It 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.
Heating time is measured while the microwave generator is
operating at full power.
The filament heat-up 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 ¡¿¡âT/t

• ¡âT is difference between initial and ending temperature.

• t is the heating time.

The power measured should be B (refer to Specifications)W ± 10.0 %.

CAUTION

1. Water load should be measured exactly to 1 liters.

2. Input power voltage should be exactly specified voltage(Refer to SPECIFICATIONS).

3. Ambient temperature should be 20 ± 2 °C (68 ± 3.6°F)

Heating time for power output:

A

(second) 70 64 60 56 52 49 47 44 42 40 38

B

(W) 600 650 700 750 800 850 900 950 1000 1050 1100

27

MEASUREMENT AND TEST

2. ELECTRICAL CONTINUITY CHECK OF INTERLOCK SWITCH

NOTE

Remove the power plug from the wall receptacle before testing.

PROCEDURE

1. Primary interlock switch
(1) Disconnect two connectors from primary interlock switch.
(2) Connect the ohm-meter leads between the terminals of the primary interlock switch.

2. Read the value of resistance between the terminals of the switch, when the door is opened, and when the door is closed.

3. Secondary interlock switch
(1) Disconnect two connectors from secondary interlock switch.
(2) Connect the ohm-meter leads between the terminals of the secondary interlock switch.
(3) Read the value of resistance between the terminals of the switch, when the door is opened,

and when the door is closed.

3. Monitor interlock switch
(1) Disconnect the lead wire connecting the primary interlock switch and interlock monitor switch from

primary interlock switch terminal.

(2) Connect the ohm-meter leads between the lead wire connector disconnected as item1 and

the power supply neutral plug pin.

(3) Read the value of resistance between the lead wire connector and the power supply neutral plug pin,

when the oven door is opened, and when the oven door is closed.

JUDGEMENT

• The value of resistance should be applied to the value specified below.

Switch Door Open Door Close

Primary interlock switch
Secondary interlock switch
Interlock monitor circuit 0

• When value obtained is not acceptable, the switch should be replaced or adjusted again.

¡Ä
¡Ä

0
0

¡Ä

28

MEASUREMENT AND TEST

3. MICROWAVE RADIATION TEST

WARNING

Make sure to check the microwave leakage before and after repair of adjustment.
Always start measuring of an unknown field to assure safety for operating personnel from microwave energy.
Do not place your hands into any suspected microwave radiation field unless the safe density level is known.
Care should be taken not to place the eyes in direct line with the source of microwave energy.
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 ).

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.

• 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.

• 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.

• 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.

• 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.

29

MEASUREMENT AND TEST

4. 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§Ù¡¾10%
Filament winding ... Approx. 0.1§Ù
Primary winding ... Approx. 1.5§Ù

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 9M§Ùonce the capacitor is charged.

(3) A shorted capacitor will show continuous continuity.
(4) An open capacitor will show constant 9M§Ù

(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§Ù in the other direction.

4. Magnetron

For complete magnetron diagnosis, refer to "Measurement of the Microwave Output
Power." 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§Ù 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.

30

WIRING DIAGRAM

31

SCHEMATIC DIAGRAM

32

SCHEMATIC DIAGRAM

33

SCHEMATIC DIAGRAM

34

EXPLODED VIEW AND PARTS LIST

1. KOC-995T0S

1) EXPLODED VIEW

35

EXPLODED VIEW AND PARTS LIST

2) PARTS LIST

REF NO. PART CODE PARE NAME DESCRIPTION QTY

1 3511712000 DOOR ASSY KOC-995T0S 1
2 3516715310 CONTROL PANEL ASSY KOC-995T0S 1
3 3515200810 STOPPER Hinge *T P/O T 2.6 1
4 7272400811 SCREW TAPTITE TT3 TRS 4×8 MFZN 2
5 5EPV048355 TRANS POWER DMR-881FS 1
6 7122401211 SCREW TAPPING T2S TRS 4×12 MFZN 1
7 3511401601 COVER WAVE GUIDE MICA 0.35T 1
8 7113400814 SCREW TAPPING T1 BIN 4×8 MFNI 1
9 3512800700 HEATER IR27835 230V 1350W 1
10 7S627W50X1 NUT HEX NUT FLANGE M5×0.8P MFZN 2
11 3512510200 GUIDE ROLLER ASSY KOC-961COS 1
12 3517202500 TRAY METAL SPP T0.8 1
13 3517400111 COUPLER TEFLON 1
14 3512505500 GUIDE AIR OULET SA1D-80 0.5T 1
15 3514801000 SENSOR TEMPERATURE PTM-K312-D6 1
16 7113400814 SCREW TAPPING T1 BIN 4×8 MFNI 1
17 3511401310 COVER INSULATOR *B SBHG-1 0.6T 1
18 3516107310 CAVITY WELD ASSY KOC-995T0S 1
19 3510801000 CABINET P.C.M T 0.6 1
20 7113401011 SCREW TAPPING T1 TRS 4×10 MFZN 5
21 35113A5Q5J CORD POWER ASSY 3×1.5 (KOC-970T1S) 1
22 7112401011 SCREW TAPPING T1 TRS 4×10 MFZN 2
23 3518605001 NOISE FILTER DWLF-MO5 1
24 7122401211 SCREW TAPPING T2S TRS 4×12 MFZN 1
25 3511800100 FAN P.P GF20 1
26 3512515300 GUIDE WIND P.P 1
27 7621401211 SCREW TAPPING T2S PAN 4×12 PW MFZN 1
28 3963513000 MOTOR SHADE POLE OEM-15DWC2-A03 1
29 7121403011 SCREW TAPPING T2S PAN 4×30 MFZN 2
30 7121300611 SCREW TAPPING T2S PAN 3×6 MFZN 2
31 3518903500 MAGNETRON THERMOSTAT OFF:150 ON:60 H#187 1
32 3518000801 MAGNETRON 2M218J(ME) I 1
33 3516003800 SPECIAL SCREW T2 FLANGE 5×8 MFZN 3
34 3512505800 GUIDE AIR WELD ASSY KOC-961C0S 1
35 3519000100 SOLENOID DC DET-SL-067 DC12V 1
36 3515101000 SPRING DAMPER HSWR 1
37 3513700300 LEVER DAMPER SUS 304 HAD:0.8 1
38 3513601000 LAMP BM 240V 25W T25 C7A V187 1
39 7112401011 SCREW TAPPING T1 TRS 4×10 MFZN 1
40 441Z724041 SHAFT DAMPER SWRM 1
41 7142400611 SCREW TAPPING T2 TRS 4×6 MFZN 1
42 3515400200 VALVE DAMPER SBHG-1 T0.5 1

36

EXPLODED VIEW AND PARTS LIST

REF NO. PART CODE PARE NAME DESCRIPTION QTY

43 3517501000 PROTECTOR DAMPER SILICON RUBBER 1
44 3518116200 H.V. TRANSFORMER JY-N 10S0-96T 1
45 3518701400 FUSE H.V. HV41A70 03 1
46 3518302300 CAPACITOR H.V. 2100V AC 1.1MICRO F 1
47 441X304112 HOLDER H.V. CAPACITOR SECC 0.8T 1
48 7272400811 SCREW TAPTITE TT3 TRS 4×8 MFZN 1
49 3518400400 DIODE H.V. HVR-1×3AB 1
50 7121400811 SCREW TAPTITE T2S PAN 4×8 MFZN 1
51 3513813500 LOCK POM BLACK 1
52 4415A17352 SW MICRO VP-533-OF 3
53 4415A66910 SW MICRO VP-531A-OF(MONITOR) 1
54 3513702600 LEVER LOCK POM 1
55 7122401211 SCREW TAPPING T2S TRS 4×12 MFZN 2
56 3966030600 MOTOR SYNCRO 220/240V 2.5W 1
57 7122400611 SCREW TAPPING T2S TRS 4×6 MFZN 2
58 3510306600 BASE SBHG 0.8T 1
59 3515202200 STOPPER HINGE *U SCP-1 T 3.2 1
60 7272400811 SCREW TAPTITE TT3 TRS 4×8 MFZN 1
61 3512101400 FOOT DASF-310 4
62 3516003800 SCREW SPECIAL T2 FLANGE 5×8 MFZN 4
63 7112401011 SCREW TAPPING T1 TRS 4×10 MFZN 6
64 3511401900 COVER INSULATOR *T ASSY KOC-991C0S 1
65 7112401011 SCREW TAPPING T1 TRS 4×8 MFZN 3
66 3510601500 BRACKET MOTOR SHADED SBHG-1 T0.8 1
67 3963513700 MOTOR SHADED POLE OEM-10DWC2-C07 1
68 7051400811 SCREW MACHINE PAN 4×8 SW MFZN 2
69 441B629071 FAN SA1D-80 T0.5 1
70 3514400410 PIPE A1100BR 1
71 3511404000 COVER INSULATOR SA1D-80 T0.7 1
72 3511800400 FAN CONVECTION SA1D-80 T0.5 1
73 75627W40X1 SPECIAL SCREW NUT FLANGE M4 MFZN 1
74 7S312X4081 SCREW TAPPING T1 TRS 4×8 SE MFZN 4
75 3513301600 INSULATOR *B CERAMIC BLANKET T0.6 1
76 3511404100 COVER REFLECTOR SA1D-80 T0.7 1
77 3518903800 THERMOSTAT OFF:160 ON:115 V#187 1
78 7121400811 SCREW TAPPING T2S PAN 4×8 MFZN 1
79 3512801800 HEATER 230V 1400W 1R18344 1
80 3513002300 HOLDER HEATER SUS304 T0.5 3
81 7121400811 SCREW TAPPING T2S PAN 4×8 MFZN 5
82 7112401011 SCREW TAPPING T1 TRS 4×10 MFZN 4
83 3511402100 COVER *B HEATPROOF PP 1
84 7112401011 SCREW TAPPING T1 TRS 4×10 MFZN 1
85 3517202601 TRAY RACK ASSY KOC-961C0S 27MM 1
86 3517202611 TRAY RACK ASSY KOC-961C0S 117MM 1
87 4417B67600 FUSE UL/FUSE NM15A 250V MF61 1

37

EXPLODED VIEW AND PARTS LIST

2. KOC-995T0S11

1) EXPLODED VIEW

38

EXPLODED VIEW AND PARTS LIST

2) PARTS LIST

REF NO. PART CODE PARE NAME DESCRIPTION QTY

1 3511712000 DOOR ASSY KOC-995T0S 1
2 3516715310 CONTROL PANEL ASSY KOC-995T0S 1
3 3515200810 STOPPER Hinge *T P/O T 2.6 1
4 7272400811 SCREW TAPTITE TT3 TRS 4×8 MFZN 2
5 5EPV048355 TRANS POWER DMR-881FS 1
6 7122401211 SCREW TAPPING T2S TRS 4×12 MFZN 1
7 3511401601 COVER WAVE GUIDE MICA 0.35T 1
8 7113400814 SCREW TAPPING T1 BIN 4×8 MFNI 1

9 3512800700 HEATER IR27835 230V 1350W 1
10 7S627W50X1 NUT HEX NUT FLANGE M5×0.8P MFZN 2
11 3512510200 GUIDE ROLLER ASSY KOC-961COS 1
12 3517202500 TRAY METAL SPP T0.8 1
13 3517400111 COUPLER TEFLON 1
14 3512505500 GUIDE AIR OULET SA1D-80 0.5T 1
15 3514801000 SENSOR TEMPERATURE PTM-K312-D6 1
16 7113400814 SCREW TAPPING T1 BIN 4×8 MFNI 1
17 3511401310 COVER INSULATOR *B SBHG-1 0.6T 1
18 3516107310 CAVITY WELD ASSY KOC-995T0S 1
19 3510801000 CABINET P.C.M T 0.6 1
20 7113401011 SCREW TAPPING T1 TRS 4×10 MFZN 5
21 35113A5Q5J CORD POWER ASSY 3×1.5 (KOC-970T1S) 1
22 7112401011 SCREW TAPPING T1 TRS 4×10 MFZN 2
23 3518605001 NOISE FILTER DWLF-MO5 1
24 7122401211 SCREW TAPPING T2S TRS 4×12 MFZN 1
25 3511800100 FAN P.P GF20 1
26 3512515300 GUIDE WIND P.P 1
27 7621401211 SCREW TAPPING T2S PAN 4×12 PW MFZN 1
28 3963513000 MOTOR SHADE POLE OEM-15DWC2-A03 1
29 7121403011 SCREW TAPPING T2S PAN 4×30 MFZN 2
30 7121300611 SCREW TAPPING T2S PAN 3×6 MFZN 2
31 3518903500 MAGNETRON THERMOSTAT OFF:150 ON:60 H#187 1
32 3518000801 MAGNETRON 2M218J(ME) I 1
33 3516003800 SPECIAL SCREW T2 FLANGE 5×8 MFZN 3
34 3512505800 GUIDE AIR WELD ASSY KOC-961C0S 1
35 3519000100 SOLENOID DC DET-SL-067 DC12V 1
36 3515101000 SPRING DAMPER HSWR 1
37 3513700300 LEVER DAMPER SUS 304 HAD:0.8 1
38 3513601000 LAMP BM 240V 25W T25 C7A V187 1
39 7112401011 SCREW TAPPING T1 TRS 4×10 MFZN 1
40 441Z724041 SHAFT DAMPER SWRM 1
41 7142400611 SCREW TAPPING T2 TRS 4×6 MFZN 1
42 3515400200 VALVE DAMPER SBHG-1 T0.5 1
43 3517501000 PROTECTOR DAMPER SILICON RUBBER 1
44 3518116200 H.V. TRANSFORMER JY-N 10S0-96T 1
45 3518701400 FUSE H.V. HV41A70 03 1

39

EXPLODED VIEW AND PARTS LIST

REF NO. PART CODE PARE NAME DESCRIPTION QTY

46 3518302300 CAPACITOR H.V. 2100V AC 1.1MICRO F 1
47 441X304112 HOLDER H.V. CAPACITOR SECC 0.8T 1
48 7272400811 SCREW TAPTITE TT3 TRS 4×8 MFZN 1
49 3518400400 DIODE H.V. HVR-1×3AB 1
50 7121400811 SCREW TAPTITE T2S PAN 4×8 MFZN 1
51 3513813500 LOCK POM BLACK 1
52 4415A17352 SW MICRO VP-533-OF 3
53 4415A66910 SW MICRO VP-531A-OF(MONITOR) 1
54 3513702600 LEVER LOCK POM 1
55 7122401211 SCREW TAPPING T2S TRS 4×12 MFZN 2
56 3966030600 MOTOR SYNCRO 220/240V 2.5W 1
57 7122400611 SCREW TAPPING T2S TRS 4×6 MFZN 2
58 3510306600 BASE SBHG 0.8T 1
59 3515202200 STOPPER HINGE *U SCP-1 T 3.2 1
60 7272400811 SCREW TAPTITE TT3 TRS 4×8 MFZN 1
61 3512101400 FOOT DASF-310 4
62 3516003800 SCREW SPECIAL T2 FLANGE 5×8 MFZN 4
63 7112401011 SCREW TAPPING T1 TRS 4×10 MFZN 6
64 3511401900 COVER INSULATOR *T ASSY KOC-991C0S 1
65 7112401011 SCREW TAPPING T1 TRS 4×8 MFZN 3
66 3510601500 BRACKET MOTOR SHADED SBHG-1 T0.8 1
67 3963513700 MOTOR SHADED POLE OEM-10DWC2-C07 1
68 7051400811 SCREW MACHINE PAN 4×8 SW MFZN 2
69 441B629071 FAN SA1D-80 T0.5 1
70 3514400410 PIPE A1100BR 1
71 3511404000 COVER INSULATOR SA1D-80 T0.7 1
72 3511800400 FAN CONVECTION SA1D-80 T0.5 1
73 75627W40X1 SPECIAL SCREW NUT FLANGE M4 MFZN 1
74 7S312X4081 SCREW TAPPING T1 TRS 4×8 SE MFZN 4
75 3513301600 INSULATOR *B CERAMIC BLANKET T0.6 1
76 3511404100 COVER REFLECTOR SA1D-80 T0.7 1
77 3518903800 THERMOSTAT OFF:160 ON:115 V#187 1
78 7121400811 SCREW TAPPING T2S PAN 4×8 MFZN 1
79 3512801800 HEATER 230V 1400W 1R18344 1
80 3513002300 HOLDER HEATER SUS304 T0.5 3
81 7121400811 SCREW TAPPING T2S PAN 4×8 MFZN 5
82 7112401011 SCREW TAPPING T1 TRS 4×10 MFZN 4
83 3511402100 COVER *B HEATPROOF PP 1
84 7112401011 SCREW TAPPING T1 TRS 4×10 MFZN 1
85 441BE15202 MOTOR SYNNCHRONOUS GM-20-24FDB1-2(OPTION) 1
86 3512300301 GASKET (BARBECUE OPTION) 1
87 7113400814 SCREW TAPPING T1 BIN 4×8 MFNI 2
88 3512506700 GUIDE ROTARY TEFLON(OPTION) 1
89 7122401211 SCREW TAPPING T2S TRS 4×12 MFZN 1
90 3517202601 TRAY RACK ASSY KOC-961C0S 27MM 1
91 3517202611 TRAY RACK ASSY KOC-961C0S 117MM 1
92 3517604300 UTENSIL BAR ASSY (BARBECUE OPTION) 1
93 4417B67600 FUSE UL/FUSE NM15A 250V MF61 1

40

PRINTED WIRING BOARD

1. CIRCUIT CHECK PROCEDURE

1. Low Voltage Transformer check

1) The low voltage transformer is located on the Base.

2) Measuring condition (input voltage) : 230 VAC / 50 Hz

KOC-995T 0S/KOC-995T0S11

LVT : DMR-881FS1

Terminal Voltage

1 3 230VAC/50Hz
6 - 7 14.0 VAC
7 - 8 14.0 VAC

9 10 2.0 VAC

·

Secondary side voltage of the low voltage transformer changes in proportion to

power source voltage.

·

The allowable tolerance of the secondary voltage is within

±

5% of normal voltage.

fluctuation of

2. Voltage check

·

Key check point ( 1~5:Micom Pin, 6:Display Pin )

NO CHECK POINT REMARK

1 PIN 63, 64
2 PIN 29, 32, 62 0 V
3 PIN 28 +5 VDC

4 PIN 45 T : 20ms (50Hz)

5 PIN 30, 31 T : 0.25us (4.0MHz)

6 PIN 1, 25 2.0 VAC(Display filament voltage)

·

Check method

NO VOLTAGE KOC-995T 0S/KOC-995T0S11

1 +5 VDC Replace R24, R15, R25, ZD3, EC2, Q3, C10, C11, C12
2 +12 VDC Replace D4, D5, EC3, C16
3 +11.3 VDC Replace R35, ZD4, Q11, EC6, C17
4 -24 VDC Replace R34, ZD1,ZD5, D6, D7, EC4, EC5

+5 VDC ± 5%

41

PRINTED WIRING BOARD

NOTE

The marks of the above corresponding voltages (+5, +12, -24VDC) are written on the PCB .
Each measuring points must be measured with GND points.

3. Display Problems

NO CAUSE MEASUREMENT RESULT REMEDY

Poor contact between

1

P.C.B. and display Filament
The display has some

2

Trouble in its segment or grid

3 Loss vacuum in the Display Find white spot

·

The display trouble shooting data

Check the voltage of display pin 1 & 25 2.0 VAC
Refer to The display trouble shooting

data below

Fix the pin 1 &
25 on the P.C.B.

Replace P.C.B.
assembly

Replace P.C.B.
assembly

TROUBLE DISPLAY NAME & PIN NO. MICOM OUTPUT IN PIN NO.

Grid 1 doesnt come on. Grid 1 (G1), 4, 7 13
Grid 2 doesnt come on. Grid 2 (G2), 10 16
Grid 3 doesnt come on. Grid 3 (G3), 14 18
Grid 4 doesnt come on. Grid 4 (G4), 17 17
Grid 5 doesnt come on. Grid 5 (G5), 21 24
Segment a doesnt come on from G1 to G5 Segment a, 23 26
Segment b doesnt come on from G1 to G5 Segment b, 22 25
Segment c doesnt come on from G1 to G5 Segment c, 20 23
Segment d doesnt come on from G1 to G5 Segment d, 19 22
Segment e doesnt come on from G1 to G5 Segment e, 18 21
Segment f doesnt come on from G1 to G5 Segment f, 16 20
Segment g doesnt come on from G1 to G5 Segment g, 15 19
Segment h doesnt come on from G1 to G5 Lower bar h, 5 14
Segment i doesnt come on from G1 to G5 Upper bar i, 6,8,9,11 15

4. Case of no microwave oscillation

1) Situation : When touching M/W button, oven lamp turns on, fan motor and turntable motor rotate and cook indicator
in the display comes on.

⇒

CAUSE : Relay 1 (RY1) does not operate.

KOC-995T 0S/KOC-995T0S11

42

PRINTED WIRING BOARD

· Check method

STAGE POINT A POINT B

RELAY ON +5 VDC GND

RELAY OFF GND +12 VDC

2) Situation : When touching M/W button, oven lamp does not turn on, turntable motor and fan moter does not rotate
but cook indicator in the display comes on.

⇒

CAUSE : Relay 2 (RY2) does not operate.

KOC-995T 0S/KOC-995T0S11

· Check method

STAGE POINT A POINT B

RELAY ON +5 VDC GND

RELAY OFF GND +12 VDC

5. Case of no heating of upper heater

- When touching GRILL button, oven lamp turns on, fan motor and turntable motor rotate and cook indicator in the dis
play comes on without heating.

⇒

CAUSE : Relay 4 (RY4) does not operate.

KOC-995T 0S/KOC-995T0S11

· Check method

STAGE POINT A POINT B

RELAY ON +5 VDC GND

RELAY OFF GND +12 VDC

43

PRINTED WIRING BOARD

6. Case of no heating of back heater

- When touching TEMP & COMBI button, oven lamp turns on, fan motor and turntable motor rotate and cook indicator
in the display comes on without heating.

⇒

CAUSE : Relay 3 (RY3) does not operate.

KOC-995T 0S/KOC-995T0S11

· Check method

STAGE POINT A POINT B

RELAY ON +5 VDC GND

RELAY OFF GND +12 VDC

7. Case of no rotating of rotisserie motor (KOC-995T0S11 Only)

- When touching ROTISSERIE button, oven lamp turns on, fan motor and turntable motor rotate and cook indicator in
the display comes on without rotating.

⇒

CAUSE : Relay 5 (RY5) does not operate.

KOC-995T0S11

· Check method

STAGE POINT A POINT B

RELAY ON +5 VDC GND

RELAY OFF GND +12 VDC

44

8. Case of no stopping of the count down timer

- When the door is opened during operation, the count down timer does not stop.

KOC-995T 0S/KOC-995 T2S

· Check method

STAGE POINT A POINT B

Door opened Open +5 VDC

Door closed Closed GND

PRINTED WIRING BOARD

9. Case of appearring Err6 on the display

KOC-995T 0S/KOC-995T0S11

· Check method

POINT WAVEFORM

A

B

C

T : 20ms (50Hz)

NOTE

If clock does not keep exact time, you must check Diode D2 & Transistor Q2 (KOC-995T0S/995T2S),

45

P.C.B. CIRCUIT DIAGRAM

1. PCB CIRCUIT DIAGRAM

46

2. PCB ASSY PART LIST

1. KOC-995T0S

P.C.B. CIRCUIT DIAGRAM

NAME SYMBOL SPECIFCATION PART CODE

M220 93X197 3514317110 1

PCB

M221 91.5X197 3514317210 1
BUZZER BZ1 BM-20K 3515600100 1
CONNECTOR WAFER CN1 515 80-15 4CW215SBD0 1
CONNECTOR WAFER CN2 YW396-02V 3519150520 1
CONNECTOR WAFER CN3 5267-04A 4076122040 1
CONNECTOR WAFER CN4 YW025-05 4076131050 1
CONNECTOR WAFER CN101 515 81-15 4CW215RBD0 1
DIGITRON DP1 SVM-5SS13 DSVM5SS13- 1
HOLDER VFD DPH PP KOR-9930 3513002000 1
IC MICOM IC1 MB89143AP-251 141SC995T0 1
SW RELAY RY1~RY4 G5G-1A-DT DC 12V 5SC0101123 4
RESONATOR CERA CR1 KBR-4.0MKSTF 5PKBR40MKS 1
C ELECTRO EC1 RS 50V 1UF CEXE1H109A 1
C ELECTRO EC2 RSS 25V 1000 UF CEXF1E102V 1
C ELECTRO EC3 RSS 35V 3300 UF CEXF1V332V 1

Q′TY

C ELECTRO EC4,EC5 RSS 50V 220 UF CEXF1H221V 2
C ELECTRO EC6 RS 50V 10 UF CEXE1H100A 1
TRANSISTOR Q1 KTA1270Y TZTA1270Y- 1
TRANSISTOR Q2, Q11 KTC3198GR TZTC3198GR 2
TRANSISTOR Q3 KTC1027Y TZTC1027Y- 1
TRANSISTOR Q4 KTC3205 TZTC3205Y- 1
TRANSISTOR Q5~Q9 KRC106M TZRC106M-- 5
C CERA AXIAL C1,C10~C18 H1KF 50V 0.1UF Z CCZF1H104Z 10
C CERA AXIAL C5,C6 H1KF 50V 0.047UF Z CCZF1H473Z 2
C CERA AXIAL C4,C7~C9 H1KF 50V 1000PF K CCZF1H102Z 4
C ARRAY CA1 8P(7) 50V 1000 PF CN7XB-102M 1
DIODE SWITCHING D1,D2 1N4148 DZN4148--- 2
DIODE RECTIFIER D3D11 1N4004A DZN4004A-- 9
R CABON FILM R1~R4,R10,R12,R19,R29 1/6W, 100K OHM J RD-AZ104J- 8
R CABON FILM R5,R8,R11,R13,R20, R35,R40 1/6W, 1K OHM J RD-AZ102J- 7
R CABON FILM R6 1/6W, 200 OHM J RD-AZ201J- 1
R CABON FILM R7 1/6W, 10K OHM J RD-AZ103J- 1

47

P.C.B. CIRCUIT DIAGRAM

NAME SYMBOL SPECIFCATION PART CODE

R CABON FILM R9 1/6W, 1M OHM J RD-AZ105J- 1
R CABON FILM R14,R16~R18,R30~R32 1/6W, 4.7K OHM J RD-AZ472J- 7
R CABON FILM R15 1/6W, 510 OHM J RD-AZ511J- 1
R CABON FILM R21~R23 1/2W, 6.8 OHM J S RD-2Z689J- 3
R CABON FILM R24 1/6W, 1.2K OHM J RD-AZ122J- 1
R CABON FILM R25 1/4W, 100 OHM J RD-4K101J- 1
R CABON FILM R26 1/4W, 120K OHM F RN-4Z1203F 1
R CABON FILM R27,R33 1/6W, 330 OHM J RD-AZ331J- 2
R CABON FILM R28 1/4W, 10K OHM F RN-4Z1002F 1
R CABON FILM R34 1/2W, 100 OHM J S RD-2Z101JS 1
R CABON FILM R36~R38 1/4W, 27 OHM J RD-4Z270J- 3
R ARRAY RA1,RA2,RA3 8P(7) 1/8 100K J RA-88X104J 3
DIODE ZENER ZD1 MTZ J 4.7B DZUZ4R7BSB 1
DIODE ZENER ZD2 MTZ J 3.0B DZUZ3R0BSB 1
DIODE ZENER ZD3 MTZ J 5.6B DZUZ5R6BSB 1
DIODE ZENER ZD4 MTZ J 12C DZUZ12BSC- 1

Q′TY

DIODE ZENER ZD5 MTZ J 24VB, 1W DZZP24B--- 1
SW ROTARY SW109 SDB161PVB17F-1- 5S10109002 1
WIRE FLAT WF1 1.25X15X90XC WSJ-159007 1
SW TACT SW101-SW108,SW110,SW111 SKHV10910A 5S50101Z90 10
JUMPER WIRE(7.5mm) J2~J4,J6,J7,J12~J14 1/0.52 TIN COATING 85801052GY 8
JUMPER WIRE(10mm) J5,J8,J9,J101,J102 1/0.52 TIN COATING 85801052GY 5
JUMPER WIRE(12.5mm) J1 1/0.52 TIN COATING 85801052GY 1
JUMPER WIRE(15mm) J10,J11,J103 1/0.52 TIN COATING 85801052GY 3

48

2. KOC-995T0S11

P.C.B. CIRCUIT DIAGRAM

NAME SYMBOL SPECIFCATION PART CODE

M220 93X197 3514317110 1

PCB

M221 91.5X197 3514317210 1
BUZZER BZ1 BM-20K 3515600100 1
CONNECTOR WAFER CN1 515 80-15 4CW215SBD0 1
CONNECTOR WAFER CN2 YW396-02V 3519150520 1
CONNECTOR WAFER CN3 5267-04A 4076122040 1
CONNECTOR WAFER CN4 YW025-05 4076131050 1
CONNECTOR WAFER CN101 515 81-15 4CW215RBD0 1
DIGITRON DP1 SVM-5SS13 DSVM5SS13- 1
HOLDER VFD DPH PP KOR-9930 3513002000 1
IC MICOM IC1 MB89143AP-251 141SC995T0 1
SW RELAY RY1~RY5 G5G-1A-DT DC 12V 5SC0101123 5
RESONATOR CERA CR1 KBR-4.0MKSTF 5PKBR40MKS 1
C ELECTRO EC1 RS 50V 1UF CEXE1H109A 1
C ELECTRO EC2 RSS 25V 1000 UF CEXF1E102V 1
C ELECTRO EC3 RSS 35V 3300 UF CEXF1V332V 1

Q′TY

C ELECTRO EC4,EC5 RSS 50V 220 UF CEXF1H221V 2
C ELECTRO EC6 RS 50V 10 UF CEXE1H100A 1
TRANSISTOR Q1 KTA1270Y TZTA1270Y- 1
TRANSISTOR Q2, Q11 KTC3198GR TZTC3198GR 2
TRANSISTOR Q3 KTC1027Y TZTC1027Y- 1
TRANSISTOR Q4 KTC3205 TZTC3205Y- 1
TRANSISTOR Q5~Q10 KRC106M TZRC106M-- 6
C CERA AXIAL C1,C10~C18 H1KF 50V 0.1UF Z CCZF1H104Z 10
C CERA AXIAL C5,C6 H1KF 50V 0.047UF Z CCZF1H473Z 2
C CERA AXIAL C4,C7~C9 H1KF 50V 1000PF K CCZF1H102Z 4
C ARRAY CA1 8P(7) 50V 1000 PF CN7XB-102M 1
DIODE SWITCHING D1,D2 1N4148 DZN4148--- 2
DIODE RECTIFIER D3D12 1N4004A DZN4004A-- 10
R CABON FILM R1~R4,R10,R12,R19,R29 1/6W, 100K OHM J RD-AZ104J- 8

R CABON FILM R5,R8,R11,R13,R20, R35,R40 1/6W, 1K OHM J RD-AZ102J- 7
R CABON FILM R6 1/6W, 200 OHM J RD-AZ201J- 1
R CABON FILM R7 1/6W, 10K OHM J RD-AZ103J- 1
R CABON FILM R9 1/6W, 1M OHM J RD-AZ105J- 1

49

P.C.B. CIRCUIT DIAGRAM

NAME SYMBOL SPECIFCATION PART CODE

R CABON FILM R14,R16~R18,R30~R32 1/6W, 4.7K OHM J RD-AZ472J- 7
R CABON FILM R15 1/6W, 510 OHM J RD-AZ511J- 1
R CABON FILM R21~R23 1/2W, 6.8 OHM J S RD-2Z689J- 3
R CABON FILM R24 1/6W, 1.2K OHM J RD-AZ122J- 1
R CABON FILM R25 1/4W, 100 OHM J RD-4K101J- 1
R CABON FILM R26 1/4W, 120K OHM F RN-4Z1203F 1
R CABON FILM R27,R33 1/6W, 330 OHM J RD-AZ331J- 2
R CABON FILM R28 1/4W, 10K OHM F RN-4Z1002F 1
R CABON FILM R34 1/2W, 100 OHM J S RD-2Z101JS 1
R CABON FILM R36~R39 1/4W, 27 OHM J RD-4Z270J- 4
R ARRAY RA1,RA2,RA3 8P(7) 1/8 100K J RA-88X104J 3
DIODE ZENER ZD1 MTZ J 4.7B DZUZ4R7BSB 1
DIODE ZENER ZD2 MTZ J 3.0B DZUZ3R0BSB 1
DIODE ZENER ZD3 MTZ J 5.6B DZUZ5R6BSB 1
DIODE ZENER ZD4 MTZ J 12C DZUZ12BSC- 1

Q′TY

DIODE ZENER ZD5 MTZ J 24VB, 1W DZZP24B--- 1
SW ROTARY SW109 SDB161PVB17F-1- 5S10109002 1
WIRE FLAT WF1 1.25X15X90XC WSJ-159007 1
SW TACT SW101-SW108,SW110,SW111 SKHV10910A 5S50101Z90 10
JUMPER WIRE(7.5mm) J2~J4,J6,J7,J12~J14 1/0.52 TIN COATING 85801052GY 8
JUMPER WIRE(10mm) J5,J8,J9,J101,J102 1/0.52 TIN COATING 85801052GY 5
JUMPER WIRE(12.5mm) J1 1/0.52 TIN COATING 85801052GY 1
JUMPER WIRE(15mm) J10,J11,J103 1/0.52 TIN COATING 85801052GY 3
JUMPER WIRE(7.5mm) SJ1 1/0.52 TIN COATING 85801052GY 1

50

DAEWOO ELECTRONICS CO., LTD

686, AHYEON-DONG MAPO-GU
SEOUL, KOREA
C.P.O. BOX 8003 SEOUL, KOREA
TELEX : DWELEC K28177-8
CABLE : “DAEWOOELEC”
E-mail : [e-mail]
FAX : [phone]
TEL : [phone]

PRINTED DATE : OCT. 1999