Daewoo KOR-146HW, KOR-146HS Service Manual

S/M No. :

Service Manual

Microwave Oven

Model: KOR-146HS

KOR-146HW

Jul. 2009

1

PRECA UTIONS T O BE OBSERVED BEFORE AND
DURING SER VICING T O AVOID POSSIBLE
EXPOSURE T O EXCESSIVE MICROW AVE 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

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

PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO AVOID POSSIBLE

EXPOSURE TO EXCESSIVE MICROWAVE ENERGY......................................................................................................1

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

FOR SAFE OPERATION ......................................................................................................................................2

FOR SAFE SERVICE PROCEDURES .................................................................................................................2

SPECIFICATIONS...............................................................................................................................................................3

EXTERNAL VIEW................................................................................................................................................................3

OUTER DIMENSION.............................................................................................................................................3

FEATURES DIAGRAM..........................................................................................................................................4

CONTROL PANEL ................................................................................................................................................5

INSTALLATION...................................................................................................................................................................6

OPERATIONS AND FUNCTIONS.......................................................................................................................................7

DISASSEMBLY AND ASSEMBLY......................................................................................................................................8

INTERLOCK MECHANISM AND ADJUSTMENT.............................................................................................................17

TROUBLE SHOOTING GUIDE .........................................................................................................................................18

MEASUREMENT 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

PCB LOCATION NO ...........................................................................................................................................30

EXPLODED VIEW AND PARTS LIST...............................................................................................................................31

2

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 PR OCEDURES

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.

CAUTION

This device is to be Serviced only by Properly Qualified Service Personnel. Consult the Service Manual for
Proper Service Procedures to Assure Continued Safety Operation and for Precautions to be Taken to Avoid
Possible Exposure to Excessive Microwave Energy.

CAUTION

MICROWAVE RADIATION
PERSONNEL SHOULD NOT BE EXPOSED TO THE MICROWAVE ENERGY WHICH MAY RADIATE FROM

THE MAGNETRON OR OTHER MICROWAVE GENERATING DEVICE IF IT IS IMPROPERLY USED OR
CONNECTED. ALL INPUT AND OUTPUT MICROWAVE CONNECTIONS. WAVEGUIDE FLANGES AND
PASKETS MUST BE SECURE. NEVER OPERATE THE DEVICE WITHOUT A MICROWAVE ENERGY
ABSORBING LOAD ATTACHED. NEVER LOOK INTO AN OPEN SAVEGUIDE OR ANTENNA WHILE THE
DEVICE IS ENERGIZED.

SAFETY AND PRECA UTIONS

3

SPECIFICATIONS

POWER SUPPLY 127V AC, 60Hz SINGLE PHASE WITH GROUNDING

INPUT POWER 1400 W

MICROWAVE ENERGY OUTPUT 1000 W

FREQUENCY 2,450MHz
OUTSIDE DIMENSIONS (W H D) 563 x 318 x 420 mm (22.2 x 12.5 x 16.5 in.)
CAVITY DIMENSIONS (W H D) 380 x 246 x 386 mm (15.0 x 9.7 x 15.2 in.)
CAVITY VOLUME 1.3 cu.ft
NET WEIGHT APPROX. 15.5 kg (34.2 lbs.)
TIMER 99 min. 99 sec.
POWER SELECTIONS 10 Levels

* Specifications are subject to change without notice.

KOR-146HS / KOR-146HW

EXTERNAL VIEW

1. OUTER DIMENSION

318

563

420

KOR-146HS / KOR-146HW

4

2. FEATURES DIAGRAM

KOR-146HW / KOR-146HS

11

Door latch - When the door is closed, it will
automatically shut off. If the door is opened while the
oven is operating, the magnetron will automatically shut
off.

22

Door seal - The door seal surfaces prevent
microwaves escaping from the oven cavity.

33

Oven cavity

44

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

55

Waveguide cover - Protects the microwave outlet from
splashes of cooking foods.

66

Oven lamp - Automatically turns on during oven
operating.

77

Safety interlock system

88

Control panel

99

Door open button - To open the door push the door
open button.

00

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.

qq

Roller guide - This must always be used for cooking
together with the glass cooking tray.

ww

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

12 3 4 56 7

w

8

9

0

q

5

3. CONTROL PANEL

KOR-146HW / KOR-146HS

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 Cook - Used to cook or specific quantities

of food.

4 Auto Cook - Used to reheat or cook many of favorite

foods.

5 Auto Defrost - Used to defrost foods.

(for weight)

6 Power - Used to set power level.

7 Clock - Used to set clock.

8 Stop/Clear - Used to stop the oven operation or to

delete the cooking data.

9 Start/Speedy Cook - Used to start the oven and also

used to set a reheat time.

22

55

66

77

99

33

11

44

88

6

6. Examine the oven after unpacking f or 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.

1. Steady, flat location.

This microwave oven should be set on a steady, flat surface.

2.Leave space behind and side.

All air vents should be kept a clearance. If all vents are covered during operation, the oven may be overheated
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.

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, 127Volts, 60Hz grounded outlet.

• Line fuse rating is 20amperes and described on EXPLODED VIEW AND PART LIST.

• Power supply cord is about 1.0 meters long.

1. A short power-supply cord is provided to reduce the risks resulting from becoming entangled in or tripping over

a longer cord.

2. Longer cord sets or extension cords are available and may be used if care is exercised in their use.

3. If a long cord or extension cord is used:

1) The marked electrical rating of the cord set or extension cord should be at least as great as the electrical
rating of the appliance.

2) The extension cord must be a grounding type 3-wire cord.

3) The longer cord should be arranged so that it will not drape over the counter top or tabletop where it can be
pulled on by children or tripped over unintentionally.

INSTALLA TION

7

OPERATIONS AND FUNCTIONS

1. Connect the mains 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 pushing 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 pad.

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 seal for

obstructions and make sure the 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 touching 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.

Touch POWER pad. Power level(Display) Approximate Percentage of Power

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%

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 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 grounding.

Do not operate on a two-wire extension cord.
The microwave oven is designed to be used while earthed.
It is imperative, therefore, to make sure it is earthed
properly before beginning repair work.

(2) Warning about the electric charge in the high voltage capacitor.

For about 30 seconds after the operation stopped and electric
charge remains in the high voltage capacitor.
When replacing or checking parts, short between oven chassis and
the negative high terminal of the high voltage capacitor by using a
properly insulated screwdriver to discharge.

4. When the 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, need a care of touching or replacing high potential parts because of

electrical shock or exposing microwave. These parts are as follows - HV Transformer, Magnetron,
HV Capacitor, HV Diode, HV fuse.

DISASSEMBLY AND ASSEMBLY

8

9

1. T o remove cabinet

1) Remove three screws on cabinet back.

2) Pull the cabinet backward.

2. T o 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.

10

3. T o remo ve door parts.

KOR-146HW

(1) Remove the gasket door from the door painting assembly.
(2) Remove the barrier screen inner from the door painting assembly.
(3) Remove the frame door from the door painting assembly.
(4) Remove the stopper hinge top assembly from the door painting assembly.
(5) Remove the spring hook and the hook from the door painting assembly.
(6) Reverse the above steps for reassembly.

A01 3512211000 FRAME DOOR KOR-136H9A27 SILICON 1
A02 3515202900 STOPPER HINGE *T AS KOR-121M0A 1
A03 3511713600 DOOR PAINTING AS KOR-131G0A 1
A04 3517006400 BARRIER SCREEN *I PE T1.0 1
A05 3512302200 GASKET DOOR PP 5113MF6 1
A06 3513101400 HOOK POM 1
A07 3515101900 SPRING PW-1 1

REF. NO PART CODE PART NAME DESCRIPTION Q'TY REMARK

DOOR ASSEMBLY : 3511713540