Daewoo | KOG-37DP0S | Service manual | Daewoo KOG-37DP0S Service manual

Daewoo KOG-37DP0S Service manual
S/M No. : G37DP0S001
Service Manual
Microwave Oven
Model : KOG-37DP0S
KOG-37FP0S
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
micro-wave 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 microwave power for any service test or inspection within the microwave generating
com-partments, 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
1. FOR SAFE OPERATION .........................................................................................................................................2
2. FOR SAFE SERVICE PROCEDURES....................................................................................................................2
SPECIFICATIONS............................................................................................................................................................3
EXTERNAL VIEW ............................................................................................................................................................4
1. OUTER DIMENSION................................................................................................................................................4
2. FEATURE DIAGRAM ...............................................................................................................................................5
3. CONTROL PANEL ...................................................................................................................................................6
INSTALLATION................................................................................................................................................................7
OPERATION AND FUNCTIONS .....................................................................................................................................8
DISASSEMBLY AND ASSEMBLY..................................................................................................................................9
INTERLOCK MECHANISM AND ADJUSTMENT ........................................................................................................18
TROUBLE SHOOTING GUIDE......................................................................................................................................19
MEASUREMENT AND TEST ........................................................................................................................................23
1. MEASUREMENT OF THE MICROWAVE POWER OUTPUT..............................................................................23
2. MICROWAVE RADIATION TEST..........................................................................................................................24
3. COMPONENT TEST PROCEDURE .....................................................................................................................25
WIRING DIAGRAM ........................................................................................................................................................26
PRINTED CIRCUIT BOARD ..........................................................................................................................................27
1. CIRCUIT CHECK PROCEDURE...........................................................................................................................27
2. P.C.B. CIRCUIT DIAGRAM....................................................................................................................................30
3. P.C.B. LOCATION NO ...........................................................................................................................................31
EXPLODED VIEW AND PARTS LIST...........................................................................................................................32
1. DOOR ASSEMBLY ................................................................................................................................................32
2. CONTROL PANEL ASSEMBLY ............................................................................................................................32
3. TOTAL ASSEMBLY................................................................................................................................................32
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.
(a) inform the manufacturer, importer or assembler,
(b) repair the unit at no cost to the owner,
(c) attempt to ascertain the cause of the excessive leakage,
(d) tell the owner of the unit not to use the unit until the oven has been brought into compliance.
3) If the oven operates with the door open, the service person should tell the user not to operate the oven and contact
the manufacturer immediately.
important
The wires 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 the the terminal in the plug which is
marked with the letter ‘E’ or by earth symbol or 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
KOG-37DP0S
POWER SUPPLY
POWER
CONSUMPTION
230V-50Hz, SINGLE PHASE WITH EARTHING
MICROWAVE
1200W
GRILL
1050W
COMBINATION
2200W
MICROWAVE ENERGY OUTPUT
800W
MICROWAVE FREQUENCY
2450MHz
OUTSIDE DIMENSIONS (W X H X D)
465x279x342mm (18.3x11.0x13.5 in.)
CAVITY DIMENSIONS (W X H X D)
290x220x306mm (11.4x8.7x12.0 in.)
NET WEIGHT
APPROX. 14Kg (30.9 lbs.)
TIMER
59 min. 90 sec.
FUNCTION SELECTIONS
MICROWAVE
POWER SELECTIONS
4 LEVELS
CAVITY VOLUME
0.7 Cu.Ft.
* SPECIFICATIONS ARE SUBJECT TO CHANGE WITHOUT NOTICE.
MODEL
KOG-37FP0S
POWER SUPPLY
POWER
CONSUMPTION
230V-50Hz, SINGLE PHASE WITH EARTHING
MICROWAVE
1200W
GRILL
1050W
COMBINATION
2200W
MICROWAVE ENERGY OUTPUT
800W
MICROWAVE FREQUENCY
2450MHz
OUTSIDE DIMENSIONS (W X H X D)
465x279x346mm (18.3x11.0x13.6 in.)
CAVITY DIMENSIONS (W X H X D)
290x220x306mm (11.4x8.7x12.0 in.)
NET WEIGHT
APPROX. 14Kg (30.9 lbs.)
TIMER
59 min. 90 sec.
FUNCTION SELECTIONS
MICROWAVE
POWER SELECTIONS
4 LEVELS
CAVITY VOLUME
0.7 Cu.Ft.
* SPECIFICATIONS ARE SUBJECT TO CHANGE WITHOUT NOTICE.
3
EXTERNAL VIEWS
1. OUTER DIMENSION
(1) KOG-37DP0S
(2) KOG-37FP0S
4
2. FEATURE DIAGRAM
1
2
3
4
5
6
7
w q
0
9
8
1. Door seal - Door seal maintains the microwave energy
within the oven cavity and prevents microwave
leakage.
9. Roller guide - This must always be used for cooking
together with the glass cooking tray.
10. Glass cooking tray - Made of special heat resistant
gkass. Food in a proper receptacle is placed on this
tray for cooking.
2. Reflector (Insulator Heater)
3. Heating Element
11. Door viewing screen - Allows viewing of food. The
screen is designed so that light can pass through, but
not the microwave.
4. Oven cavity
5. Safety interlock system
6. Door release button - By pushing this button the latch
system cut off all circuits and stops the oven before
the door is opened.
12. Door hook - When the door is closed, it will
automatically shut off. If the door is opened while the
oven is operating, the magnetron will immediately stop
operating.
7. Metal Rack
8. Coupler - This fits over the shaft in the center of the
ovens cavity floor. This is to remain in the oven for all
cooking.
5
3. CONTROL PANEL
Auto Def. Grill Combi g
e
Hight Low Warm Timer
r
KOG-37DP
1
2
3
Frozen
Pizza
Chicken
Piece
Croissant
WEIGHT
t
y
1. Small Piece
2. Big Piece
Combi Grill
u
M/W
p
Kitchen
Timer
ur
1ho
10m.
d
Grill
i
Combi
Clock
in.
10m
1m.
Stop/Clear
in.
1m
10s.
Start
13. Display - Cooking time, power level, indicators and
present time are displayed.
o
a
s
f
19. Combination - Used to cook combination.
20. Kitchen Timer - Used to set a minute timer.
14. Auto Weight - Used to cook or reheat three foods by
setting the weight.
21. Clock - Used to set clock.
22. Time set pads - Used to set the cooking time and
the present time.
15. Auto weight Defrost - Used to defrost two foods by
setting the weight.
23. Stop/Clear - Used to stop the oven operation or to
erase all entries.
16. Weight set pads - Used to set the weight.
17. M/W - Used to set microwave power level.
24. Start - Used to start the oven operation.
18. Grill - Used to cook grill.
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 shouls 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 possinle.
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 11 amperes, 220~240 Volts, 50Hz.
• Power supply cord is about 0.8 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 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 od 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 instruction 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
OPERATIONS AND FUNCTIONS
1. Connect the mains lead to an electrical socket-outlet.
2. After placing the food in a suitable utensil, open the oven door and put it on the glass turntable, Glass turntable
must always be in place during cooking.
3. Close the door securely.
4. When the oven door is opened, the light turns off.
5. The oven door can be opened at any time during operation by touching the door release button on the control
panel.
The oven will automatically shut off. To restart the oven, close the door and then touch START.
6. Each time a pad is touched, a BEEF will sound to acknowledge the touch.
7. The oven automatically cook on full power unless set to a lower power level.
8. The display will show “88 : 88” when the oven is plugged in.
9. Time clock returns to the present time when the cooking time ends.
10. When the STOP/CLEAR pad is touched during the oven operation, the oven stops cooking and all information
retained. To erase all information (except the present time), touch the STOP/CLEAR pad once more. If the oven
door is opened during the oven operation, all information is retained.
11. If the START pad is touched and the oven does not operate, check the area between the door and door is closed
securely. The oven will not start cooking under the door is not completely closed or the program has not been set.
12. When using the GRILL or COMBI mode ;
• Do not open the door so often, the temperature inside the oven decrease and the cooking may not complete in
setting time.
• Never touch the oven window and metal interior of the oven when taking food in and out, because of the
temperature inside the oven and door is very high.
• When using these modes, be careful as the tray will be hot to touch, use oven gloves or pot holders while
handling tray.
Make sure the oven is properly installed and plugged into the electrical outlet.
Wattage output chart
The power level is set by pressing the Power pad. The chart shows the display, the power level and the wattage of power.
Touch Power pad.
Once
Twice
3 times
4 times
Power level (Display)
HI
LOW
WARM
DEF
8
Approximate Wattage of Power
800
470
140
Tapered
DISASSEMBLY AND ASSEMBLY
Cautions to be observed when trouble shooting.
Unlike many other appliances, the microwave oven is a 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 begining 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
insulted screw driver to discharge.
4. When the 15A fuse is blown out due to the operation of
the monitor switch; replace primary, secondary interlock
switch and monitor switch.
Refer to next page for the necessary adjustment.
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 repairing 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-H.V. Transformer,
Magnetron, H.V. Capacitor, H.V. Diode.
9
1. To remove cabinet.
1) Remove three screws on cabinet back.
2) Push the cabinet backward.
2. To remove door assembly.
1) Remove a screw which secure the stopper hinge top.
2) Remove the door assembly from top plate of cavity
3) Reverse the above for reassembly.
NOTE
After replacing the door assembly, perform a check of correct alignment with the hinge and cavity front plate.
10
3. To remove door parts
DOOR ASSEMBLY
KOG-37DP0S: 3511714420
KOG-37FP0S: 3511714450
REF NO.
PART CODE
PART NAME
A01
3512203880
FRAME DOOR
3512205200
A02
DESCRIPTION
Q’TY
REMARK
PP SI83C
1
KOG-37DP
FRAME DOOR
PP SI83C
1
KOG-37FP
3517007300
BARRIER-SCREEN*0
PET T0.125
1
A03
3515204100
STOPPER SINGE *T AS
KOR-63150S
1
A04
3511706100
DOOR PAINTING AS
KOR-61150S
1
A05
3517002800
BARRIER-SCREEN *I
T0.1
1
A06
3512300200
GASKET DOOR
PP
1
A07
3513100700
HOOK
POM
1
A08
3515101300
SPRING HOOK
PW -1
1
11
(1) Remove the gasket door from door painting assembly.
(2) Remove the door frame from door painting assembly.
(3) Remove the stopper hinge top from door painting assembly.
(4) Remove the spring and the hook.
(5) Remove the barrier screen outer from door frame.
(6) 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 a screws on stopper hinge top, and then push
the door to contact the door seal to oven front surface.
Tighten two screws.
(2) To reduce gap located on part ‘B’
Loosen two screws on stopper hinge under, and then
push the door to contact the door seal to oven front
surface.
Tighten two screws.
NOTE : A small gap may be acceptable if the microwave leakage does not exceed 4mW/cm2.
12
5. To remove control panel parts.
CONTROL-PANEL ASSEMBLY
KOG-37DP0S: 3516721640
KOG-37FP0S: 3516721650
REF NO.
PART CODE
Q’TY
REMARK
B01
3518521670
SWITCH MEMBREANE
KOG-37DP0S
1
KOG-37DP
3518520970
SWITCH MEMBRANE
KOG-37FP0S
1
KOG-37FP
3516725300
CONTROL PANEL
ABS SG-0760D, SG-175
1
KOG-37DP
3516725350
CONTROL PANEL
ABS SG-0760D, SG-175
1
KOG-37FP
B03
3514322470
PCB AS
KOG-57GP0S
1
B04
7122401211
SCREW TAPPING
T2S TRS 4X12 MFZN
3
B05
3513702710
LEVER DOOR OPEN
PP
1
B06
441G430171
SPRING BUTTON
SWP DIA0.7
1
B07
3516906940
BUTTON DOOR OPEN
ABS SG-0760D, SG-175
1
KOG-37DP
3516906950
BUTTON DOOR OPEN
ABS SG-0760D, SG-175
1
KOG-37FP
B02
PART NAME
DESCRIPTION
1) Remove the screw which secure the control panel, push up two snap fits and draw forward the control panel assembly.
2) Remove the door open lever from the control panel.
3) Remove four screws which secure the PCB assembly to control panel.
4) Disconnect membrane tail from the connector of the PCB assembly.
5) Detach membrane from the control panel.
6) Remove door open button and button spring from the control panel.
7) Reverse the above steps for reassembly.
13
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.
NOTE : 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
8. To remove fan motor assembly.
(1) Remove a screws 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 reassembly.
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.
15
10. To remove tray motor.
(1) Remove the coupler in the cavity.
(2) Turn the set upside down.
(3) Cut the tray motor cover part from the base plate.
(4) Remove the tray motor cover.
(5) Remove a screw which secure the tray motor.
(6) Remove the tray motor.
(7) Reverse the above steps for reassembly except for
securing the tray motor cover with screw.
11. To remove heater assembly.
(1) Remove the three nuts.
(2) Remove the insulator heater assembly.
(3) Reverse the above steps for reassembly.
16
12. To remove heater parts.
REF.NO
PART CODE
PART NAME
DESCRIPTION
C01
7392500008
NUT HEX
6N-2-5 SUS
1
C02
3515000600
SPACER INSULATOR *I
C3771BD
2
C03
3513301100
INSULATOR HEATER
SPP T0.8
1
C04
3512803400
HEATER
230V 1000W 1R67994001
1
C05
7002500613
SCREW MACHINE
TRS 5X6 MFCR
1
C06
7002400413
SCREW MACHINE
TRS 4X4 MFCR
2
17
QTY
REMARK
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 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 NO condition and presses the button of the secondary interlock switch to
bring it under ON condition.
ADJUSTMENT
Interlock monitor switch
When the door is closeed, the interlock monitor switch should be changed(NO condition) before other switches
are closed.
When the door is opened, the interlock monitor switch should be changed(NC condition) after other switches are
opened.
(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 one mounting screw.
NOTE
Microwave emission test should be performed after adjusting interlock mechanism. If the microwave emission
exceed 4mW.cm2, readjust interlock mechanism.
18
TROUBLE SHOOTING GUIDE
Following the procedure below to check if the oven is defective or not.
1) Check earthing 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 transformer, disconnect one lead 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.
NOTE
When electric parts are checked, be sure the power cord is not inserted the wall outlet.
Check wire hamess, wiring and connected of the terminals and power cord before check the parts listed below.
(TROUBLE 1) Oven does not operate at all : any inputs can not be accepted.
CONDITION
CHECK
Fuse blows.
Check continuty of interlock
monitor switch with door closed
(COM ↔ NC)
RESULT
Continuity
CAUSE
Malfunction of
interlock
monitor switch
REMEDY
Replace
NOTE 1
No Continuity
Check continuity of both
primary and secondary
interlock switch with door
colosed
No Continuity
Continuity
Continuity
Check continuity of primary
interlock switch contact with door
partially open until interlock
monitor switch contact close
(COM ↔ NC)
Check continuity of primary
winding of low voltage
transformer
0Ω or infinite
Approx.
150~310
(normal)
Fuse again
blows
Disconnect high voltage fuse
and operate the unit
19
Replace
Malfunction of
interlock switch
Shorted contacts
of primary
interlock switch.
Defective low
voltage
transformer
Defective high
voltage
transformer
NOTE 1
Replace
NOTE 1
Replace
Replace
CONDITION
Outlet has
proper
voltage Fuse
does not
blow.
CHECK
RESULT
CAUSE
REMEDY
No
Continuity
Defective
magnetron
Replace
Check continuity of magnetron
Check continuity of
noise filter board
No
Continuity
Defective line
filter board
Replace
Check continuity of
power supply cord
No
Continuity
Open power
supply cord
Replace
Normal
Defective touch
control circuit
Replace
NOTE
All these switches must be replaced at the same time, please refer to "Interlock Mechanism And Adjustment".
(TROUBLE 2) Display shows all figures selected, but oven does not start cooking, even though
desired program and time are set and start pad is tapped.
CONDITION
CHECK
RESULT
CAUSE
REMEDY
Turntable
motor and
oven lamp
do not turn
on
Check continuity of primary
interlock switch
No
Continuity
Malfunction of
primary interlock
switch
Adjust or
replace
Check continuity of secondary
interlock and D.O.M. switches
No
Continuity
Malfunction of
primary interlock
and D.O.M.
switch
Adjust or
replace
Check D.C. voltage being
supplied to RELAY (RY2) coil
0V
Defective touch
control circuit
Replace
Approx.
15 VDC
Faulty contacts of
RELAY (RY2) or
open relay coil
20
Replace
(TROUBLE 3) No microwave oscillation even though fan motor rotates.
CONDITION
CHECK
RESULT
No
microwave
oscillation
Check continuity of high
voltage fuse
No
Continuity
CAUSE
REMEDY
Replace high voltage fuse
Check continuity if high
voltage capacitor terminals
with wires removed
Continuity
Defective high
voltage
transformer
Replace
Check continuity of high voltage
rectifier in forward and backward
direction with DC megger
Continuity in
backward
direction
Defective high
voltage rectifier
Replace
Connect megger leads to
magnetron terminal and
magnetron body
Continuity
Defective
magnetron
Replace
Defective high
voltage
transformer
Replace
0 Ω or ∞
Check resistance of primary and
secondary coil of high voltage
transformer
No
Continuity
Check continuity of magnetron
with wires removed
No
Continuity
Check continuity of filament
terminal of high voltage
transformer
Defective
magnetron
Defective high
voltage
transformer
0V
Defective touch
control circuit
Check D.C. voltage being
supplied to RELAY (RY1) coil
Approx
15 VDC
21
Faulty
contacts or
RELAY (RY1)
or open
relay coil
Replace
Replace
Replace
Replace
(TROUBLE 4) The following visual conditions inditions indicate a probable defective touch control
circuit or membrane switch assembly
1. Incomplete segments,
1) Segments missing.
2) Partical segments missing.
3) Digit flickering other than normal display slight flickering.
4) " 88:88" does not display when power is on.
2. A distinct change in the display are not on when they should be.
3. One or more digits in the display are not on when they should be.
4. Display indicates a number different from one touched.
5. Specific numbers (for example 2 or 3) will not display when the panel is touched.
6. Display does not count down or up with time cooking or clock operation.
7. Oven is programmable and cooks normally but no display shows.
8. Display obviously jumps in time while counting down.
9. Display counts down noticeable too fast while cooking.
10. Display does not show the time of day when clear pad is touched.
11. Oven lamp and turntable motor do not stop although cooking is finished. Check if the RELAY 2 contacts close. If they
are close, replace touch control circuit.
CONDITION
CHECK
Display does
not show
programming
at all, even if
keyboard is
touched.
Check each pad for
continuity of the membrane
keyboard for the following
keyboard check procedure
RESULT
Normal
Abnormal
CAUSE
REMEDY
Malfunction
of touch
control circuit
of control box
sub-assembly
Replace
control box
sub-assembly
Malfunction
of the membrane
keyboard
Replace the
membrane
keyboard
NOTE
Before following the particular steps listed above in the trouble shooting guide for the membrane keyboard's,
failure, please check for the continuity of each wire-harness between the membrane keyboard and P.C.B.
assembly.
22
MEASUREMENT AND TEST
1. MEASUREMENT OF THE MICROWAVE POWER OUTPUT
Microwave output power can be checked by indirectly mmeasuring the temperature rise of a certain amount of water
exposed to the microwave as directed below.
PROCEDURE
1. Microwave power output measurement is made with the microwave oven supplied at rated voltage and operated at
its maximum microwave power setting with a load of 100 ± 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). If 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.
(Refer to table as following)
Heating time is measured while the microwave
generator is operating at full power. The filament heatup 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 X ∆ T/t
• ∆ T is difference between initial and ending temperature.
• t is the heating time.
The power measured 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
23
2. MICROWAVE RADIATION TEST
CAUTION
1. Make sure to check the microwave leakage before and after repair of adjustment.
2. Always start measuring of an unknown field to assure safety for operating personnel from microwave energy.
3. Do not place your hands into any suspected microwave radiation field unless the safe density level is known.
4. Care should be taken not to place the eyes in direct line with the source of microwave energy.
5. 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.
1) 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.
2) 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.
3) 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.
4) 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.
24
3. 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. 110 Ω±10%
Filament winding ... Approx. 0 Ω
Primary winding ... Approx. 1 Ω
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 10MΩ once the capacitor charged.
3) A shorted capacitor will show continuous continuity.
4) An open capacitor will show constant 10MΩ.
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 Ω in the other
direction.
4. Magnetron
For complete magnetron diagnosis, refer to "Measurement of the Microwave Power Output." 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 Ω 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.
25
WIRING DIAGRAM
26
PRINTED CIRCUIT BOARD
1. CIRCUIT CHECK PROCEDURE
1. Low voltage transformer check
The low voltage transformer is located on the P.C.B.
Measuring condition: Input voltage: 230V / Frequency: 50Hz
Terminal Voltage
LOAD
NO LOAD
6- 4, 7
AC 12.6 V
AC 14.7 V
NOTE
1. Refer to Ciruit Diagram (point 4).
2. Secondary side voltage of the low voltage transformer changes in proportion to fluctuation of power source
voltage.
3. The allowable tolerance of the secondary voltage is within ± 5% of nominal voltage.
2. Voltage Check
- Key check point
- NO
Check method
CHECK POINT
1
IC1 PIN 7, 41, 42
2
IC1 PIN 23
REMARK
5VDC
T : 20ms(50Hz)
3
IC1 PIN 8 OR 9
T : 250 ns(4MHz)
NO
MEASURE POINT
WAVE FORM
REMEDY
REMARK
1
MP1
DC 5V±0.25V
Replace VL1, EC1
NO LOAD
2
MP2
DC 12V±0.2V
Replace EC2, D6, 8, 9
NO LOAD
NOTE
Each measure point must be measured with GND points.
27
MP1
MP2
Mesurement point
28
3. When there is no microwave oscillation
1) When touching START pad, oven lamp does not turn on.
Fan motor do not rotate, but cook indicator in display comes on.
Cause : RELAY 2 does not operate. refer to Circuit Diagram (point 3)
- Check method
POINT
A
STATE
B
RELAY 2 ON
5VDC
GND
RELAY 2 OFF
GND
12VDC
2) When touching START pad, oven lamp turns on.
Fan motor and turntable rotate and cook indicator in display comes on.
Cause : RELAY 1 does not operate. refer to Circuit Diagram (point 2)
- Check method
POINT
A
STATE
B
RELAY 1 ON
5VDC
GND
RELAY 1 OFF
GND
12VDC
4. When there is no grill oscillation.
Cause : RELAY 3 does not operate.
- Check method
refer to Circuit Diagram (point 6)
POINT
A
STATE
B
RELAY 3 ON
5VDC
GND
RELAY 3 OFF
GND
12VDC
5. When the door is opened during operation, the count down timer does not stop.
refer to Circuit Diagram (point 1)
- Check method
POINT
A
STATE
1) DOOR OPEN
OPEN
5VDC
2) DOOR CLOSED
CLOSE
GND
CHECK NO
1
B
METHOD
REMEDY
Check the stage(ON, OFF) of the door open monitor
switch by resistance measurement.
Replace door open monitor switch.
6. When the digital clock does not operate properly.
refer to Circuit Diagram (point 5)
POINT
A
WAVE FORM
0
T: 20 ms(50Hz)
29
If clock does not keep
exact time, you must
check C6, D7, R19, R20,
ZD2.
2. P.C.B. CIRCUIT DIAGRAM
30
3. P.C.B. LOCATION NO
(1) KOG-37DP0S / KOG-37FP0S
NO
NAME
SYMBOL
SPECIFICATION
PART CODE
Q'TY
1
BUZZER
BZ1
BM-20K
3515600100
1
2
C ARRAY
CA1
6P(5) 1000PF M 50V
CN5XB-102M
1
3
CAPACITOR ELEC
EC1
RSS 100MF 16V
CEXF1C101V
1
4
CAPACITOR ELEC
EC2
25V RSS 1000MF
CEXF1E102V
1
5
CONNECTOR WAFER
CN1
YW396-02V
3519150520
1
6
CONNECTOR FILM
CN2
FCZ 254-10P
441M367150
1
7
CONNECTOR WAFER
CN3
YW396-05AV
3519150510
1
8
DIODE RECTIFY
D1~D7
1N4148
DZN4148---
7
9
DIODE RECTIFY
D8,D9
KN4004A
DZN4004A--
2
10
DIODE ZENER
ZD1
UZ- 3.3BSB 1/2W
DZUZ3R3BSB
1
11
DIODE ZENER
ZD2
UZ- 5.1BSB 1/2W
DZUZ5R1BSB
1
12
PCB MAIN
M173
81.5X139.9
3514321160
1
13
R ARRAY
RA1
6P(5) 1/8 100K J
RA-86X104J
1
14
RESISTOR
R1~8
1/6W 330 5%
RD-AZ331J-
8
15
RESISTOR
R10,11,13,22
1/6W 1K 5%
RD-AZ102J-
4
16
RESISTOR
R9,17,18
1/6W 100K 5%
RD-AZ104J-
3
17
RESISTOR
R14
1/6W 100 5%
RD-AZ101J-
1
18
RESISTOR
R12,15,20
1/6W 10K 5%
RD-AZ103J-
3
19
RESISTOR
R16
1/6W 1M 5%
RD-AZ105J-
1
20
RESISTOR
R19
1/6W 4.7K 5%
RD-AZ472J-
1
21
RESISTOR
R21
1/4W 51 5%
RD-4Z510J-
1
22
RESONATOR CERA
CR1
CRT 4.00MS
5P4R00MTS-
1
23
IC REGULATOR
VL1
MC7805C
1CPMC7805C
1
24
TRANSISTOR
Q1~5
KRA-110M
TZRA110M--
5
25
TRANSISTOR
Q6,7,9~12
KRC-106M
TZRC106M--
6
26
TRANSISTOR
Q8
KTA-1266Y
TZTA1266Y-
1
27
TRANS POWER
LVT
DMR-631FS
5EPV035303
1
28
WIRE COPPER
J1~8,10,11
1/0.52 TIN COATING(7.5mm)
85801052GY
10
29
WIRE COPPER
J9
1/0.52 TIN COATING(12.5mm)
85801052GY
1
30
WIRE COPPER
SJ1
1/0.52 TIN COATING(7.5mm)
85801052GY
1
31
IC MICOM
IC1
HD404054A75S
147S57GP00
1
32
SW RELAY
RY1,RY3
G5G-1A DC12V
5SC0101121
2
33
SW RELAY
RY2
OJ-SS-112LM
5SC0101404
1
34
CAPACITOR CERA
C2~6
50V HIKF 0.1MF Z
CCZF1H104Z
5
35
CAPACITOR CERA
C1
50V 4700PF
CCZF1H473Z
1
36
LED DISPLAY
DP1
ELF-316GWB-07
DELF316GWB
1
31
EXPLODED VIEW AND PARTS LIST
1. DOOR ASSEMBLY
Refer to Disassembly and assembly
2. CONTROL PANEL ASSEMBLY
Refer to Disassembly and assembly
3. TOTAL ASSEMBLY
32
(1) KOG-37DP0S / KOG-37FP0S
REF NO
PART CODE
PART NAME
DESCRIPTION
Q'TY
A00
DOOR AS
Refer to disassembly and assembly
1
B00
CONTROL PANEL AS
Refer to disassembly and assembly
1
C00
3513302700
INSULATOR HEATER AS
Refer to disassembly and assembly
1
F01
3510805300
CABINET AS
PCM T0.5
1
F02
7112401011
SCREW TAPPING
T1 TRS 4*10 MFZN
3
3516109010
CAVITY WELD AS
CAVITY WELD AS
1
3516109610
CAVITY JOINT AS
CAVITY JOINT AS
1
F04
7S627W50X1
NUT HEX
NUT FLANGE M5X0.8P MFZN
2
F05
7122401211
SCREW TAPPING
T2S TRS 4*12 MFZN
1
F06
3518904500
THERMOSTAT
OFF : 100 ON : 90 HN #187
1
F07
7121300611
SCREW TAPPING
T2S PAN 3X16 MFZN
1
F08
7122401211
SCREW TAPPING
T2S TRS 4*12 MFZN
1
F09
7112401011
SCREW TAPPING
T1 TRS 4*10 MFZN
2
F10
35113A5QJ5
CORD POWER AS
3X1.5 80X80 120-RTML 1.4M
1
F11
4413A90012
CLAMP POWER CORD
NYLON66
1
F12
7112401011
SCREW TAPPING
T1 TRS 4*10 MFZN
1
F13
7122401211
SCREW TAPPING
T2S TRS 4*12 MFZN
1
F14
7112401011
SCREW TAPPING
T1 TRS 4X10 MFZN
1
F15
7S627W50X1
NUT HEX
NUT FLANGE M5X0.8P MFZN
1
4414A25110
FUSE
250V 15A 65TS
1
4414A25100
FUSE
250V 15A MDA15
1
F17
3518606100
NOISE-FILTER
DWLF-M13
1
F18
7121403011
SCREW TAPPING
T2S PAN 4X30 MFZN
2
3963513100
MOTOR SHADED POLE
230V 17W OEM-10DWC2-A07
1
3963512310
MOTOR SHADED POLE
230V 20W MW10CA-M02
1
F20
3512517000
GUIDE WIND
PP
1
F21
3511800300
FAN
PP+30% GLASS
1
F22
3518002400
MAGNETRON
2M218J(F)
1
F23
3516004000
SPECIAL SCREW
T2 BOLT FLANGE 5X12 DACRO
1
F24
7272400811
TAPTITE SCREW
TT3 TRS 4*8 MFZN
1
F25
3513003200
HOLDER HV CAPACITOR
SECC T0.6
1
F26
3518302200
CAPACITOR HV
2100VAC 0.98µF #187
1
F27
3518400900
DIODE HV AS
HVR-1X-30B #187
1
F28
3518701100
FUSE HV
5KV 0.55A HV-41A55-02
1
F29
3518113701
TRANS HV
DY-N80S0-63T
1
F30
3516003700
SPECIAL SCREW
TT3 HEX 4X8 FLG MFZN
4
F31
3510311710
BASE
SBHG T0.7
1
F03
F16
F19
33
REF NO
PART CODE
F32
7112401011
SCREW TAPPING
T1 TRS 4*10 MFZN
5
F33
3512100900
FOOT
PP DASF-130
2
F34
7272400811
TAPTITE SCREW
TT3 TRS 4X8 MFZN
1
F35
3515201101
STOPPER HINGE *U
SCP-1 T2.5
1
F36
4415A17352
SW MICRO
VP-533A-OF SPNO #187 200G
1
F37
4415A66910
SW MICRO
VP-531A-OF/SZM-V16-FA-61
1
F38
4415A17352
SW MICRO
VP-533A-OF SPNO #187 200G
2
F39
3513702600
LEVER LOCK
POM
1
F40
3513811700
LOCK
POM
1
F41
3513601600
LAMP
BL 240V 25W T25 C7A H187
1
F42
7121400611
SCREW TAPPING
T2S PAN 4X6 MFZN
1
3966310100
MOTOR SYNCRO
220V 2.5W GM-16-24FD12
1
3966310110
MOTOR SYNCRO
220V 2.5W M2LJ49ZT52
1
F44
3518905300
THERMOSTAT
OFF: 75 ON: 65 H #187 NB
1
F45
3513003400
HOLDER THERMOSTAT
PBT
1
F46
7272400811
SCREW TAPTITE
TT3 TRS 4X8 MFZN
1
F47
4078502031
BUTTON LOCKING
PP HONAM A353
2
F48
3511405100
COVER WAVE GUIDE
MICA T0.35
1
F49
3517400620
COUPLER
XAREC
1
F50
3514700710
ROLLER
TEFLON
3
F51
3512517300
GUIDE ROLLER
PP 5113MF6 A353B
1
F52
3517203600
TRAY
GLASS
1
F53
3517206900
TRAY RACK AS
KOG-37150S 110MM
1
F43
PART NAME
DESCRIPTION
34
Q'TY
DAEWOO ELECTRONICS CO., LTD.
686, AHYEON-DONG MAPO-GU
SEOUL, KOREA
C.P.O. BOX 8003 SEOUL, KOREA
TELEX: DWELEC K28177-8
CABLE: “DAEWOOELEC”
PRINTED DATE: Jul. 2001
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