Daewoo KOC-1B0K6S User manual

Service Manual
Microwave Oven
Model: KOC-1B0K6S
S/M No. : C1B0K6S001
DAEWOO ELECTRON CS CO., LTD.
http://svc.dwe.co.kr Feb. 2001

1
PRECAUTIONS TO BE OBSERVED BEFORE AND
DURING SERVICING TO AVOID POSSIBLE
EXPOSURE TO EXCESSIVE MICROWAVE ENERGY
(a)Do not operate or allow the oven to be operated with the door open.
(b)Make the following safety checks on all ovens to be serviced before activating the magnetron or other
microwave source, and make repairs if necessary: (1) Interlock operation, (2) Proper door closing, (3)
Seal and sealing surfaces (arcing, wear, and other damage), (4) Damage to or loosening of hinges and
latches (5) Evidence of dropping or abuse.
(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.
TABLE OF CONTENTS
1. SAFETY AND PRECAUTIONS....................................................................................................................................2
2. SPECIFICATIONS ........................................................................................................................................................3
3. EXTERNAL VIEW.........................................................................................................................................................3
1. OUTER DIMENSION.............................................................................................................................................3
2. FEATURE DIAGRAM.............................................................................................................................................4
4. INSTALLATION............................................................................................................................................................5
5. CONTROL PANEL .......................................................................................................................................................6
6. DISASSEMBLY AND ASSEMBLY..............................................................................................................................7
7. INTERLOCK MECHANISM AND ADJUSTMENT.....................................................................................................17
8. TROUBLE SHOOTING GUIDE..................................................................................................................................18
9. MESUREMENT AND TEST .......................................................................................................................................23
1. MEASUREMENT OF THE MICROWAVE POWER OUTPUT ...........................................................................23
2. MICROWAVE RADIATION TEST .......................................................................................................................24
3. COMPONENT TEST PROCEDURE...................................................................................................................25
4. COMPONENT ACTION.......................................................................................................................................26
10. WIRING DIAGRAM...................................................................................................................................................27
11. EXPLODED VIEW AND PARTS LIST.....................................................................................................................28
12. PRINTED CIRCUIT BOARD ....................................................................................................................................32
13. P.C.B CIRCUIT DIAGRAM.......................................................................................................................................36

2
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.

3
3. EXTERNAL VIEW
2. SPECIFICATIONS
MODEL KOC-1B0K6S
POWER SUPPLY 230V~50HZ, SINGLE PHASE WITH EARTHING
MICROWAVE 1500W
POWER GRILL 1600W
CONSUMPTION CONVECTION 2300W
COMBINATION 2300W
MICROWAVE ENERGY OUTPUT 1000W(IEC705)
MICROWAVE FREQUENCY 2450MHz
OUTSIDE DIMENSIONS (W X H X D) 560X344X542mm (22.0X13.0X21.3 in.)
CAVITY DIMENSIONS (W X H X D) 368.5X246X376.5mm (14.5X9.7X14.8 in.)
NET WEIGHT APPROX. 21.5kg (47.6 lbs.)
TIMER 60 minutes
FUNCTION SELECTIONS MICROWAVE/ GRILL/ CONVECTION/ COMBINATION
POWER SELECTIONS 10 LEVELS
CAVITY VOLUME 1.2 Cu. Ft
* Specifications are subject to change without notice.
1. OUTER DIMENSION

4
11.DOOR HOOK
When the door is closed, it will automatically lock shut. If door is opened while oven is operating, the magnetron
will immediately stop operating.
12.DOOR VIEWING SCREEN
Allows viewing of food. The screen is designed so that light can pass through, but not the microwave.
13.METAL RACK
14.TOP HEATER
Turns on when convection, grill and combi cooking is selected.
15.OVEN LAMP
Automatically turns on during oven operating.
16.SAFETY INTERLOCK SYSTEM
17.CONTROL PANEL
18.TURNTABLE TRAY
Rotates during cooking and ensure even distribution of Microwaves.
It can also be used as a cooking utensil.
19.ROLLER GUIDE
This must always be used for cooking together with the turntable tray.
10. COUPLER
This fits over the shaft in the center of the ovens cavity floor. This is to remain in the oven for all cooking.
11. CONVECTION OUTLET & FAN
12. UNDER HEATER
13. OVEN FRONT PLATE
14.DOOR SEAL
Door seal maintains the microwave energy within the oven cavity and prevents microwave leakage.
2. FEATURE DIAGRAM

5
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 12 amperes, 230V, 50Hz.
• 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
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.
4. INSTALLATION
EARTHING INSTRUCTIONS
WARNING
Improper use of the earthing plug can result in a risk of electric shock.
Consult a qualified electrician of 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.

6
5. CONTROL PANEL
clock
memory
cake
m
w
/
clear
stop/ start/
speedy cook
auto cook
crusty
more
c
g
less
auto
defrost
l
l
i
i
o
m
b
r
4
3
2
1
language
7
6
5
8
9
12
15
17
18
20
22
10
11
13
14
16
19
23
21
c
o
n
v
e
c
t
i
o
n
t
i
m
e
w
e
i
g
h
t
q
u
n
t
i
t
y
DISPLAY WINDOW
1. MICROWAVE - indicator, showing microwaving
in progress.
2. DEFROST- indicator, showing defrosting in
progress.
3. GRILL(upper grill heater) - indicator, showing
griling in progress.
4. GRILL(lower grill heater) - indicator, showing
griling in progress.
5. CONVECTION - indicator, showing
convectioning in progress.
6. CHILD LOCK - indicator.
7. % - percentage microwave power level
indicator.
BUTTONS
8. LANGUAGE - press to select the language.
9. Clock - Used to set clock.
10. LESS - Use to remove time from cooking.
11. MORE - Use to add time to cooking.
12. M/W - Press to select microwave power level.
13. COMBI - Press to select combi cooking mode.
14. AUTO DEFROST - Press to select defrost
menu.
15. CONVECTION - Press to select convection
temperature.
16. GILL - Press to select grill.
17. CAKE - Press to select cake menu.
18. CRISP - Press to select srisp menu.
19. AUTO COOK - Press to select auto cook
menu.
20. MEMORY - Use to set favorite cooking mode.
21. START/SPEEDY COOK- Press to start a
programme, also for speedy start (each press
adds 30 seconds microwave cooking time).
22. STOP/CLEAR - Press once to stop a
programme, and twice to cancel a programme.
23. DIAL KNOB - Use to set time, weight and
quantity.

7
6. DISASSEMBLY AND ASSEMBLY
- Cautions to be observed when trouble shooting.
Unlike many other appliances, the microwave oven is high-voltage, high-current equipment. It is completely safe
during normal operation. However, carelessness in servicing the oven can result in an electric shock or possible
danger from a short circuit. You are asked to observe the following precautions carefully.
1. Always remove the power plug from the outlet before servicing.
2. Use an insulated screwdriver and wear rubber gloves when servicing the high voltage side.
3. Discharge the high voltage capacitor before touching any oven components or wiring.
(1) Check the grounding.
Do not operate on a two-wire extension cord.
The microwave oven is designed to be used while grounded.
It is imperative, therefore, to make sure it is grounded
properly before beginning repair work.
(2) Warning about the electric charge in the high voltage capacitor.
For about 30 seconds after the operation has stopped, electric
charge remains in the high voltage capacitor.
When replacing or checking parts, short between oven chassis
and the negative high terminal of the high voltage capacitor by
using a properly insulated screwdriver to discharge.
4. When the 20A fuse is blown out due to the operation of the monitor
switch; replace primary interlock switch, secondary interlock switch
and interlock monitor switch.
5. After repair or replacement of parts, make sure that the screws are
properly tightened, and all electrical connections are tightened.
6. Do not operate without cabinet.
CAUTION : Service personnel should remove their watches whenever working close to or replacing the magnetron.
WARNING : When servicing the appliance, take care when touching or replacing high potential parts because of
electrical shock or exposing microwave. These parts are as follows - HV Transformer, Magnetron,
HV Capacitor, HV Diode.

8
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 which secure the stopper hinge top.
2) Remove the door assembly from top plate of cavity.
3) Reverse the above for assemby.
3. To remove door parts.
NOTE: After replacting the door assembly, perform a
check of correct alignment with the hinge and
cavity front plate.
REF NO. PART CODE PART NAME DESCRIPTION Q’TY REMARK
A01 3512204700 FRAME DOOR PC 1
A02 3517006900 BARRINER-SCREEN*O TEMP GLASS T3.2 1
A03 3515201011 SCREW TAPPING T1S TRS 4X10 MFZN 2
A04 3515204900 STOPPER HINGE*T AS KOC-1B0K0S 1
A05 3512302300 GASKET DOOR PBT 1
A06 7122401211 SCREW TAPPING T2S TRS 4X12 MFZN 1
A07 3513101200 HOOK POM 1
A08 3515101800 SPRING HOOK PW1 1
A09 3511714100 DOOR SEAL AS KOC -1B0K0S 1
A10 3512603500 HANDLE DOOR PC 1

9
(1) Remove the gasket door from door plate.
(2) Remove screws from door plate.
(3) Remove the door frame from door plate.
(4) Remove the stopper hinge top from door plate.
(5) Remove the spring and the hook.
(6) Remove the handle door and barrier screen outer from door frame.
(7) Reverse the above steps for reassembly.
4. Method to reduce the gap between the door seal and the oven front surface.
(1) To reduce gap located on part ‘A’.
• Loosen two screws on stopper hinge top, and then push the door
to contact the door seal to oven front surface.
• Tighten two screws.
(2) To reduce gap located on part ‘B’.
• Loosen two screws on stopper hinge under, and then push the
door to contact the door seal to oven front surface.
• Tighten two screws.
NOTE : A small gap may be acceptable if the microwave leakage does not exceed 4mW/cm
2
.

10
5. To remove control panel parts.
REF NO. PART CODE PART NAME DESCRIPTION Q’TY REMARK
B01 3511605000 DECORATOR C-PANEL ABS XR-401 H-2938 1
B02 3511605100 DECORATOR RING ABS SG-175 SG-0760D 1
B03 3515501700 WINDOW DISPLAY PMMA 1
B04 3516724100 CONTROL PANEL ABS XR-401 H-2938 1
B05 3516908300 BUTTON FUNCTION-A ABS SG-175, AF-0760D 1
B06 3516908500 BUTTON FUNCTION-C ABS SG-175, SG-0760D 1
B07 3516908400 BUTTON FUNCTION-B ABS SG-175, SG-0760D 1
B08 7122401211 SCREW TAPPING T2S TRS 4X12 MFZN 3
B09 3514323010 PCB MAIN AS KOC-1B0K0S 1
B10 7121301011 SCREW TAPPING T2S PAN 3X10 MFZN 7
B11 3514323110 PCB SUB AS KOC-1B0K0S 1
B12 3516908600 BUTTON FUNCTION-D ABS SG-175, SG-0760D 1
B13 3516908700 BUTTON FUNCTION-E ABS SG-175, SG-0760D 1
B14 3516908200 BUTTON START ABS SG-175, SG-0760D 1
B15 3511606000 KNOB VOLUME ABS SG-175, SG-0760D 1
(1) Remove the screw which secure the control panel, push up two snap fits and draw forward the control panel assembly.
(2) Remove four screws(B08) which secure the PCB Main ASS’Y.
(3) Pull out the Main PCB assembly(B09).
(4) Remove eight screws(B10) which secure the PCB Sub ASS’Y.
(5) Pull out the Sub PCB assembly(B11).
(6) Pull out the Knob volume(B15) from the Sub PCB assembly.
(7) Pull out five buttons from the control panel.
(8) Pull out Decorator ring(B02) and Window display(B03) from the control panel.
(9) Pull out Window display(B01) from the control panel.
(10)Reverse the above steps for reassembly.

11
CAUTION : 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/cm
2
for a fully assembled oven with door normally closed.
Magnetron antenna
Metallic
gasket
plate
Cooling fin
Filament
terminal
6. 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
7. To remove magnetron.
1) Remove a screw which secure the magnetron.
2) Remove the magnetron.
3) Reverse the above steps for reassembly.

12
8. To remove wind guide assembly.
1) Remove a screw for earthing.
2) Remove the noise filter from the wind guide.
3) Remove a screw which secure the wind guide assembly.
4) Draw forward the wind guide assembly.
5) Pull the fan from the motor shaft.
6) Remove two screws which secure the motor shaded pole.
7) Remove the motor shaded pole.
8) Reverse the above steps for reasembly.
9. To remove H.V.transformer.
1) Remove four screws holding the H.V.transformer.
2) Remove the H.V.transformer.
3) Reverse the above steps for reassembly.

13
10. To remove Lamp assembly parts.
1) Remove a screw 1 and pull out Guide air outlet 2 .
2) Remove two screws
4 and pull out insulator heater *t 3 .
3) Pull out the Lamp assembly.
4) Remove two screws
6 pull out the Lamp assembly.
5) Pull out the Holder lamp assembly
7 from the Cover lamp 5 .
6) Pull out the Lamp
8 from the Holder lamp assembly 7 .
7) Reverse the above steps for reassembly.
REF NO. PART CODE PART NAME DESCRIPTION Q’Y REMARK
1 7112401011 SCREW TAPPING T1 TRS 4X10 MFZN 1
2 3512520500 GUIDE AIR OUTLET SA1D T0.6 1
3 3513302800 INSULATOR HEATER*T SBHG T0.5 1
4 7112401011 SCREW TAPPING T1 TRS 4X10 MFZN 2
5 3511407800 COVER LAMP STS430 T0.5 1
6 7112401011 SCREW TAPPING T1 TRS 4X10 MFZN 2
7 3513003900 HOLDER LAMP AS KOC-1B0K0S 1
8 3513602600 LAMP HALOGEN 2
9 3511407810 COVER LAMP GLASS T2.0 1

14
11. To remove Top heater assembly parts.
1) Remove a screw 1 and pull out Guide air outlet 2 .
2) Remove two screws
4 and pull out insulator heater *t 3 .
3) Pull out the Top heater assembly.
4) Pull out the Harness heater
5 .
5) Pull out the Braket heater*t from the Cover heater*t
8 .
6) Pull out the Heater miraclon
7 from the Cover heater*t 8 .
7) Reverse the above steps for reassembly.
REF NO. PART CODE PART NAME DESCRIPTIOT Q’TY REMARK
1 7112401011 SCREW TAPPING T1 TRS 4X10 MFZN 1
2 3512520500 GUIDE AIR OUTLET SA1D T0.5 1
3 3513302800 INSULATOR HEATER*T SBHG T0.6 1
4 7112401011 SCREW TAPPING T1 TRS 4X10 MFZN 2
5 3512767000 HARNESS HEATER KOC-1B0K0S 1
6 3510607700 BRACKET HEATER *T SA1D T0.5 1
7 3512803800 HEATER MIRACLON 115V 550W 270MM 2
8 3511407600 COVER HEATER *T STS430 T0.5 1

15
12. To remove Rear heater assembly parts.
1) Remove a screw 1 and pull out Cover motor *B 2 .
2) Remove a screw
3 and pull out Cover *B 4 .
3) Pull out the Harness convection-B
5 .
4) Remove four screws
t and then pull out the Rear heater assembly.
5) Remove a Nut
q and the pull out the Fan convection 0 and Washer plain 9 .
6) Remove three screws
8 and then separate the Cover heater *B 7 and the lnsulator heater *B r .
7) Pull out two Heaters
6 from the Cover Heater *B 7 .
8) Remo two screw
e and then separate the lnsulator heater *B r and Motor shaded pole y .
9) Remove the C-Ring
i and then pull out the Fan u from Motor shaft.
10)Reverse the above steps for reassebly.
REF NO. PART CODE PART NAME DESCRIPTION Q’TY REMARK
1 7112401011 SCREW TAPPING T1 TRS 4X10 MFZN 1
2 3511407300 COVER MOTOR*B SA1D-80 T0.5 1
3 7112401011 SCREW TAPPING T1 TRS 4X10 MFZN 2
4 3511407400 COVER*B SBHG T0.6 1
5 3512766900 HARNESS CONVECTION-B KOC-1B0K0S 1
6 3512803800 HEATER MIRACLON 115V 550W 270MM 2
7 3511407700 COVER HEATER*B SA1D-80 T0.5 1
8 7113400814 SCREW TAPPING T1 BIN 4X8 MFNI 3
9 7400504011 WASHER PLAIN PW1-4 MFNI 1
10 3511800700 FAN CONVECTION SA1D-80 T0.5 1
11 75627W50X1 NUT HEX NUT FLANGE M5X0.8P MFZN 1
12 3512766800 HARNESS CONVECTION-A KOC-1B0K0S 1
13 7051400811 SCREW MACHINE PAN 4X8 SW MFZN 2
14 3513302900 INSULATOR HEATER*B SA1D T0.5 1
15 7113400814 SCREW TAPPING T1 BIN 4X8 MFNI 4
16 3963514300 MOTOR SHADED POLE 230V 50HZ MW10CA-TO 1
17 3511800800 FAN PP GF20 1
18 7402704600 C-RING CR-5 SK5 1

16
13. To remove Motor synchro. And Under heater assembly parts.
1) Cut the Motor syncro. cover parts from the base plate.
2) Remove a screw and then pull out Motor syncro.
3) Remove a screw
1 and then pull out the Under heater *U. assembly.
4) Remove a screw
5 .
5) Pull out the Heater *U
4 from the Cover heater *U 2 .
6) Reverse the above steps for reassembly.
14. To remove Trans Power..
1) Remove a screw 1 .
2) Pull out the Trans Power
2 from the base plate.
3) Reverse the above steps for reassembly.
REF NO. PART CODE PART NAME DESCRIPTION Q’TY REMARK
1 7112401011 SCREW TAPPING T1 TRS 4X10 MFZN 1
2 3511407500 COVER HEATER *U STS430 T0.5 1
3 3515304000 SUPPORTER HEATER *U STS430 T0.5 1
4 3512802000 HEATER *U 230V 400W R18374001 1
5 7113400814 SCREW TAPPING T1 BIN 4X8 MFZN 1
REF NO. PART CODE PART NAME DESCRIPTION Q’TY REMARK
1 7112401011 SCREW TAPPING T1 TRS 4X10 MFZN 1
2 5FPV041411 TRANS POWER DMR-210FST 1

17
7. 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 and interlock monitor switch
When the door is closed, the hook pushes the lock lever downward. The lock lever presses the button of the interlock
monitor switch to bring it under OFF condition and presses the button of the secondary interlock switch to bring it under
ON condition.
(3) Adjustment steps
a) Loosen the one mounting screw.
b) Adjust interlock switch assembly position.
c) Make sure that lock lever moves smoothly after adjustment is completed.
d) Tighten completely two mounting screws.
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.
NOTE :
Microwave emission test should be performed after adjusting interlock mechanism.
If the microwave emission exceed 4mW/cm
2
, readjust interlock mechanism.

18
8. TROUBLE SHOOTING GUIDE
Following the procedure below to check if the oven is defective or not.
1) Check grounding before trouble checking.
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 tranformer, disconnect one load wire from these
parts and check continuity with the AC plug removed. To do otherwise may result in a false reading or damage to
your meter.
(TROUBLE 1) Oven does not operate at all : any inputs can not be accepted.
NOTE : When electric parts are checked, be sure the power cord is not inserted the wall outlet.
Check wire harness, wiring and connection of the terminals and power cord before check the parts listed below.
CONDITION CHECK
Check continuity of
interlock monitor switch with
door closed
( COM NC )
Check continuity of
both primary and secondary
interlock switch with door closed
Malfunction of
Interlock
monitor switch
Malfunction of
interlock switch
RESULT
Continuity
No continuity
CAUSE REMEDY
Replace
(COM↔NC)
Fuse blows.
Replace
Shorted contacts
of primary
interlock Switch
Continuity Replace
Check continuity of
primary interlock switch contact
with door partially open until
interlock monitor switch contact
close
( COM NC close )
Defective low
voltage
transformer
Defective
high voltage
transformer
0Ωor infinite Replace
Replace
Check continuity of
primary winding of low voltage
transformer
Disconnect high voltage
fuse and operate the unit
No
Continuity
Continuity
Approx.
530Ω
( normal )
Fuse again
blows

19
CONDITION CHECK
Check continuity of
magnetron Defective
magnetron.
RESULT
No
continuity
CAUSE REMEDY
Replace
Outlet has
proper
voltage
fuse does not
blow? Check continuity of noise filter
board Defective line
filter board
No
continuity Replace
Check continuity of
power supply cord
Defective touch
control circuit Replace
Open power
supply cord
No
continuity
continuity
Replace
NOTE : All these switches must be replaced at the same time, please refer to (7.Interlock mechanism and
adjust) for adjustment instructions
(TROUBLE 2)
Display shows all figures selected, but oven does not start cooking, even though desired program and time
are set and start button is tapped.
CONDITION CHECK
Check continuity of
primary interlock switch Malfunction of
primary interlock
switch
RESULT
No
continuity
CAUSE REMEDY
Adjust or
replace
Turn table
motor and
oven lamp
do
not turn on
Check D.C voltage
being supplied to
RELAY(RY4) coil
Fault contacts
of RELAY
(RY4) or open
relay coil.
Replace
Check continuity of
secondary interlock
and D.O.M switch
Malfunction of
secondary
Interlock and
D.O.M switch
No
continuity Adjust or
replace
Defective touch
control Circuit
0V
Approx.
24V DC
Replace