DAEWOO ELECTRONICS KOC-995T0S User manual

Service Manual
Microwave Oven
Model: KOC-995T0S
KOC-995T0S11
DAEWOO ELECTRONICS CO., LTD.
S/M No. : C995T0S110

1
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
(a) Do not operate or allow the oven to be operated with the door open.
(b)Makethe followingsafetychecks onallovens tobeserviced beforeactivatingthe magnetronorother 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)Amicrowave leakagechecktoverify compliancewiththeFederal performancestandardshould beperformedon
each oven prior to release to the owner.
PRECAUTIONS TO BE OBSERVED BEFORE AND
DURING SERVICING TO AVOID POSSIBLE
EXPOSURE TO EXCESSIVE MICROWAVE ENERGY

2
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.
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.
IMPORTANT
This oven is designed for counter-top use only.
NOTE

3
SPECIFICATIONS
* SPECIFICATIONS ARE SUBJECT TO CHANGE WITHOUT NOTICE.
MODEL KOC-995T0S KOC-995T0S11
POWERSUPPLY 230V~50Hz 230V~50Hz
POWER
CONSUMPTION
MICROWAVE 1,550W 1,550W
GRILL 1,400W 1,400W
CONVECTION 1,450W ( Temporary Maximum Power Consumption : 2,800W )
COMBINATION 2,950W (Simultaneous) 1,550W (Sequentional)
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 MICROWAVE/GRILL/CONVECTION/COMBI/
ROTISSERIE(option)
POWERSELECTIONS 10 LEVELS
CAVITY VOLUME 1.0 Cu.Ft.

4
EXTERNAL VIEW
1. OUTER DIMENSION

5
EXTERNAL VIEW
2. FEATURE DIAGRAM
2-1. KOC-995T0S
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. Metal rack
12. Convection outlet & Fan

6
EXTERNAL VIEW
2-2. KOC-995T0S11
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. Metal rack
12. Convection outlet & Fan
13. Guide Rotary
14. Motor Synchro
15. Utensil Bar

7
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 soon.
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.
This appliance must be earthed. In the event of an electrical short circuit, earthing reduces the risk of the electric shock by pro-
viding an escape wire for the electric current. This appliance is equipped with
acord having aearthing wire witha earthing plug.The plugmust be pluggedinto an outletthat is properlyinstalled andearthed.
EARTHING INSTRUCTIONS
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.
WARNING

8
CONTROL PANEL
1. KOC-995T0S

9
CONTROL PANEL
2. KOC-995T0S11

10
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.
Service personnel should remove their watches whenever working close to or replacing the magnetron.
CAUTION
Whenservicing the appliance,needa care oftouchingor replacing high potentialpartsbecause of electricalshockor
exposing microwave. These parts are as follows - HV Transformer, Magnetron, HV Capacitor, HV Diode.
WARNING

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.

12
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

13
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
13512508000 GUIDE AIR WELD AS KOC-961C0S 1
23515400200 VALVE DAMPER SBHG-1 T0.5 1
33517501000 PROTECTOR DAMPER SILICON RUBBER 1
43519000100 SOLENOID DC DET-SL-007 DC12V 1
57142400611 SCREW TAPPING T2 TRS 4 5 6 MFZN 1
63513700300 LEVER DAMPER SUS 304 H DIA :0.8 1
73515101000 SPRING DAMPER HSWR 1
83513601000 LAMP BM 240V 25W T25 1
97112401011 SCREW TAPPING T1 TRS 4 5 10 MFZN 1
10 441Z724041 SHAFT DAMPER SWRM 1
11 7112401011 SCREW TAPPING T1 TRS 4 5 10 MFZN 2
12 441Q523060 FIXTURE SOLENOID SWC PI1.0 1

14
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
13963513700 MOTOR SHADED POLE 230V 50HZ OEM-10DWC2-C07 1
27S312X4081 SCREW TAPPING T1 TRS 4 5 8 SE MFZN 4
33510601500 BRACKET MOTOR SHADED SBHG-1 T0.8 1
47051400811 SCREW MACHINE PAN 4 5 8 SW MFZN 2
5441B629071 FAN SA1D-80 T0.5 1
63511404000 COVER INSULATOR SA1D-80 T0.7 1
73513301600 INSULATOR *B CERAMIC BLANKET T0.6 1
83511404100 COVER REFLECTOR SA1D-80 T0.7 1
93514400410 PIPE A1100BR 1
10 3513002300 HOLDER HEATER SUS304 T0.5 3
11 7121400811 SCREW TAPPING T2S PAN 4 5 8 MFZN 5
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 T1 TRS 4 5 10 MFZN 4
16 3518903800 THERMOSTAT OFF:160 ON:115 V#187 1
17 7121400811 SCREW TAPPING T2S PAN 4 5 8 MFZN 1

14
7. To remove magnetron
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/cm²for a fully
assembled oven with door normally closed.
WARNING

16
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 1SMOG
B04 3513404620 KNOB VOLUME ABS XR-401 1COATING
B05 3516905120 BUTTON FUNCTION ABSXR-401 1COATING
B06 3516907200 BUTTON FUNCTION ABSXR-401 1COATING
B07 3516906320 BUTTON FUNCTION ABSXR-401 2COATING
B08 3514321800 PCB SUB AS KOC-995T0S 1
B09 7621301011 SCREW TAPPING T2S PAN 3x10 PW MFZN 6
B10 3514312810 PCBMAIN AS KOC-995T0S 1
3514320330 PCBMAIN AS KOC-995T0S11 1
B11 7122401211 SCREW TAPPING T2S TRS 4x12 MFZN 4

17
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.
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 1MIRROR
A05 3512204020 FRAME DOOR PC 1
A06 3511603200 DECORATOR DOOR *T STS304T0.6 H/L 1
A07 3511603300 DECORATOR DOOR *U STS304T0.6 H/L 1
A08 3515203610 STOPPER HINGE *T AS KOC-995T0S 1
A09 3512602410 HANDLE DOOR *T AS ABS XR-401 SILVER 1KOC-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
After replacing the door assembly, perform a check of
correct alignment with the hinge and cavity front plate.
NOTE

18
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).
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
fromthe ovencavity during thecook cycle. Thisfunction doesnot require thatthe door beair-tight, moisture (conden-
sation) 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.
NOTE

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.
.