DONGBU DAEWOO ELECTRONICS KOR-164H0W User manual

Service Manual
Microwave Oven
Model: KOR-164H0W
S/M No. : OR164H0W01
May. 2014
✔Caution
: In this Manual, some parts can be changed for improving,
their performance without notice in the parts list. So, if you
need the latest parts information, please refer to PPL(Parts
Price List) in Service Information Center (http://svc.dwe.co.kr).
Dongbu Daewoo Electronics

2
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.
(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........................................................................................................................................3
FOR SAFE OPERATION...........................................................................................................................................3
FOR SAFE SERVICE PROCEDURES .....................................................................................................................3
SPECIFICATIONS ............................................................................................................................................................4
EXTERNAL VIEW .............................................................................................................................................................5
OUTER DIMENSION .................................................................................................................................................5
FEATURE DIAGRAM.................................................................................................................................................6
CONTROL PANEL.....................................................................................................................................................7
INSTALLATION ................................................................................................................................................................8
OPERATIONS AND FUNCTIONS ...................................................................................................................................9
DISASSEMBLY AND ASSMBLY...................................................................................................................................10
INTERLOCK MECHANISM AND ADJUSTMENT.........................................................................................................17
TROUBLE SHOOTING GUIDE ......................................................................................................................................18
MESUREMENT AND TEST............................................................................................................................................22
MEASUREMENT OF THE MICROWAVE POWER OUTPUT................................................................................22
MICROWAVE RADIATION TEST ...........................................................................................................................23
COMPONENT TEST PROCEDURE .......................................................................................................................24
WIRING DIAGRAM.........................................................................................................................................................25
PRINTED CIRCUIT BOARD...........................................................................................................................................26
CIRCUIT CHECK PROCEDURE.............................................................................................................................26
PCB CIRCUIT DIAGRAM ........................................................................................................................................29
P.C.B. LOCATION NO. ............................................................................................................................................30
EXPLODED VIEW AND PARTS LIST ...........................................................................................................................31
DOOR ASSEMBLY ..................................................................................................................................................31
CONTROL PANEL ASSEMBLY ..............................................................................................................................31
TOTAL ASSEMBLY .................................................................................................................................................31

SAFETY AND PRECAUTIONS
3
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.

MODEL
POWER SUPPLY
POWER MICROWAVE
CONSUMPTION GRILL
COMBINATION
MICROWAVE ENERGY OUTPUT
MICROWAVE FREQUENCY
OUTSIDE DIMENSIONS (W x H x D)
CAVITY DIMENSIONS (W x H x D)
NET WEIGHT
TIMER
FUNCTION SELECTIONS
POWER SELECTIONS
4
SPECIFICATIONS
KOR-164H0W
230V~50Hz, SINGLE PHASE WITH earthing
1400 W
1000 W
2450 MHz
589 X 339 X 486mm
399 X 274 X 426mm
APPROX. 18.5kg
99min. 90sec.
MICROWAVE
11 LEVELS
* Specifications are subject to change without notice.

5
EXTERNAL VIEW
1. OUTER DIMENSION

6
1. DOOR SEAL
Door seal maintains the microwave within the oven cavity and prevents microwave leakage.
2. DOOR HOOK
When door is closed, it will automatically lock shut. If door is opened while oven is operating, magnetron tube will
immedi-ately stop operating.
3. DOOR SCREEN
Allows viewing of food. Microwave cannot pass through perforations in screen.
4. SPATTER SHIELD
Protects the microwave outlet from splashes of cooking foods.
5. OVEN LAMP
Automatically turns on during oven operating.
6. SAFETY INTERLOCK SYSTEM
7. CONTROL PANEL
8. GLASS COOKING TRAY
Made of special heat resistant glass. The tray must always be in proper position before operating. Do not cook food
directly on the tray..
9. OVEN FRONT PLATE
10. ROLLER GUIDE
Supports the glass cooking tray.
1
94
8
0
7
3
256
2. FEATURE DIAGRAM

7
1. Time set pad - Used to set the cooking time and the present time.
2. Display - Cooking time, power level, indicators and present time are displayed.
3. One touch - Used to cook or reheat specific quantities of food.
4. More - Used to add time to cooking.
5. Less - Used to remove time from cooking.
6. Auto defrost - Used to defrost foods.(for weight)
7. Power - Used to set power level.
8. Defrost - Used to defrost foods.(for time)
9. Kitchen Timer - Used as a minute timer, delay cooking, hold setting after cooking.
10. Clock - Used to set clock.
11. Stop/Clear - Used to stop the oven operation or to delete the cooking data.
12. Start /Speedy cook- Used to start the oven and also used to set a reheat time.
Dish
Warmer
M/W Def. Timer Lock g
Fresh
Vegetable
Frozen
Vegetable
Auto Defrost
Poutly Meat
1hour
Power
10m.
Pasta
Beverage
Frozen
Pizza
10min.
1m.
1min.
10s.
Defrost
Kitchen
Timer
Stop/
Clear
Start/
Speedy Cook
Clock
Fish
2
3
7
9
q
6
1
8
0
w
4
5
3. CONTROL PANEL

8
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 oven 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 6 amperes, 230Volts, 50Hz grounded outlet.
• 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.

9
OPERATIONS AND FUNCTIONS
1. Connect the main lead to an electrical outlet.
2. After placing the food in a suitable container, open the oven door and put it on the glass tray. The glass tray must
always be in place during cooking.
3. Close the door securely.
4.
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.
5. Each time a pad is touched, a BEEP will sound to acknowledge the touch.
6. The oven automatically cook on full power unless set to a lower power level.
7. The display will show : 0 when the oven is plugged in.
8. Time clock returns to the present time when the cooking time ends.
9. 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.
10. 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 completely closed or the program has been reset.
Wattage output chart
The power level is set by pressing the POWER pad. The chart shows the display, the power level and the percentage
of power.
Make sure the oven is properly installed and plugged into the electrical outlet.
once P-HI 100%
twice P-90 90%
3 times P-80 80%
4 times P-70 70%
5 times P-60 60%
6 times P-50 50%
7 times P-40 40%
8 times P-30 30%
9 times P-20 20%
10 times P-10 10%
11 times P-00 0%
Touch Power pad Power level (Display) Approximate Percentage of Power

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 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 12A fuse is blown 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, HV Fuse.

11
1. To remove cabinet
1) Remove four screws on cabinet back.
2) Push the cabinet backward.
2. 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 for reassembly.
NOTE : After replacing the door assembly, perform a check of correct alignment with the hinge and cavity front plate.

12
3. To remove door parts.
(1) Remove the gasket door(A01) from door plate.
(2) Remove the door frame (A08) from door plate.
(3) Remove two screws(A09) from door plate.
(4) Remove the door handle (A15) and handle supporter (A14) from door plate.
(5) Remove the four door decorators (A10~A13) from door frame.
(6) Remove the stopper hinge top(A03) from door plate.
(7) Remove the spring(A06) and the hook(A05).
(8) Remove the barrier screen outer(A07) from door frame.
(9) Reverse the above steps for reassembly.
A01 3512301800 GASKET DOOR PP 1
A02 3517005200 BARRIER-SCREEN *I PE T0.1 1
A03 3513101600 HOOK POM 1
A04 3515102000 SPRING HOOK PW1 1
A05 3511710500 DOOR PAINTING AS KOR-161H0A 1
A06 3515204400 STOPPER HINGE *T AS KOR-162J0A 1
A07 3517005360 BARRIER-SCREEN *O TEMP GLASS T3.2 MIRROR 1
A08 7122402011 SCREW TAPPING T2S TRS 4X20 MFZN 2
A09 3512203930 FRAME DOOR ABS SG-175 SG-0760D 1
A10 3511607700 DECORATOR DOOR *T SUS T0.5 1
A11 3511607800 DECORATOR DOOR *U SUS T0.5 1
A12 3511607900 DECORATOR DOOR *L SUS T0.5 1
A13 3511608000 DECORATOR DOOR *R SUS T0.5 1
A14 3512604310 HANDLE DOOR AL 1
REF. NO PART CODE PART NAME DESCRIPTION Q'TY REMARK
DOOR ASSEMBLY : 3511710430

13
(1) To reduce gap located on part ‘A’
• Loosen two screws on the stopper hinge top, and then
push the door to contact the door seal to the oven front
surface.
• Tighten two screws.
(2) To reduce gap located on part ‘B’
• Loosen two screws on the stopper hinge under, and then
push the door to contact the door seal to the oven front
surface.
• Tighten two screws.
(3) To reduce gap located on part ‘C’
• Loosen the screw on the interlock switch assembly located
the top of the oven body.
• Draw the interlock switch assembly inward as possible to
engage with the hook on the door bottom.
• Tighten a screw.
(4) To reduce gap located on part ‘D’
• Loosen the screw on the interlock switch assembly located
the bottom of the oven body.
4. Method to reduce the gap between the door seal and the oven front surface.
NOTE : A small gap may be acceptable if the microwave leakage does not exceed 4mW/cm
2
.

14
5. To remove control panel parts.
B01
B02
B03
B04 B05
(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 which secure the PCB assembly to control panel.
(3) Disconnect membrane tail from the connector of the PCB assembly.
(4) Detach membrane from the control panel.
(5) Reverse the above steps for reassembly.
B01 3518521860 SWITCH MEMBRANE KOR-164H0S 1
B02 3511608500 DECORATOR C-PANEL SUS T0.5 1
B03 3516719160 CONTROL-PANEL ABS SG-175, SG-0760D 1
B04 PKMPMSFH91 PCB MAIN MANUAL AS 16 (1000W, S, 10, 99) 1
B05 7122401211 SCREW TAPPING T2S TRS 4*12 MFZN 4
REF. NO PART CODE PART NAME DESCRIPTION Q'TY REMARK

15
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/cm
2
for a fully assembled oven with door normally closed.
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.

16
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.

17
INTERLOCK MECHANISM AND ADJUSTMENT
ADJUSTMENT :
Interlock monitor switch
When the door is closed, 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.
NOTE :
Microwave emission test should be performed after adjusting interlock mechanism.
If the microwave emission exceed 4mW/cm
2
, readjust interlock mechanism.
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 NO condition. The lock lever 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.
RD/GY
WH:WHITE
BK:BLACK
RD:RED
BL:BLUE
GN:GREEN
GY:GRAY
BK/BK WH
RD
BK
BL
BL
WH
WH/BK
RD/RD
(REAR)
D.O.M switch

18
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 continuty of interlock
monitor switch with door closed
(COM ↔ NC)
Check continuity of both
primary and secondary
interlock switch with door
colosed
Malfunction of
interlock
monitor switch
Malfunction of
interlock switch
RESULT
Continuity
No Continuity
CAUSE REMEDY
Replace
NOTE 1
Fuse blows.
Replace
NOTE 1
Shorted contacts
of primary
interlock switch.
Continuity Replace
NOTE 1
Check continuity of primary
interlock switch contact with door
partially open until interlock
monitor switch contact close
(COM ↔ NC)
Defective low
voltage
transformer
0Ωor infinite
Approx.
310~420
(normal)
Replace
Check continuity of primary
winding of low voltage
transformer
Defective high
voltage
transformer
Fuse again
blows
Replace
Disconnect high voltage fuse
and operate the unit
No Continuity
Continuity

19
CONDITION CHECK
Check continuity of magnetron Defective
magnetron
RESULT
No
Continuity
CAUSE REMEDY
Replace
Outlet has
proper
voltage Fuse
does not
blow.
CONDITION CHECK
Check continuity of primary
interlock switch
Malfunction of
primary interlock
switch
RESULT
No
Continuity
CAUSE REMEDY
Adjust or
replace
Turntable
motor and
oven lamp
do not turn
on
Check continuity of secondary
interlock and D.O.M. switches
Malfunction of
primary interlock
and D.O.M.
switch
No
Continuity
Adjust or
replace
Check D.C. voltage being
supplied to RELAY (RY2) coil
Defective touch
control circuit
0 V Replace
Faulty contacts of
RELAY (RY2) or
open relay coil
Approx.
15 VDC
Replace
Check continuity of
noise filter board
Defective line
filter board
No
Continuity
Replace
Check continuity of
power supply cord
Open power
supply cord
No
Continuity
Replace
Defective touch
control circuit
Normal Adjust
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.

20
CONDITION CHECK
Check continuity of high
voltage fuse
RESULT
No
Continuity
Check continuity if high
voltage capacitor terminals
with wires removed
Replace high voltage fuse
Continuity
CAUSE
Defective high
voltage
transformer
REMEDY
Replace
No
microwave
oscillation
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
Check resistance of primary and
secondary coil of high voltage
transformer
0 Ωor ∞Defective high
voltage
transformer
Replace
Check continuity of magnetron
with wires removed
No
Continuity Defective
magnetron
Replace
Check continuity of filament
terminal of high voltage
transformer
No
Continuity Defective high
voltage
transformer
Replace
Check D.C. voltage being
supplied to RELAY (RY1) coil
0 V
Defective touch
control circuit
Replace
Approx
15 VDC Faulty
contacts or
RELAY (RY1)
or open
relay coil
Replace
(TROUBLE 3) No microwave oscillation even though fan motor rotates.