Daewoo KOR-61151 User manual

Service Manual
Microwave Oven
KOR-61155
KOR-61151
DAEWOO ELECTRONICS CO., LTD.

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)Mark 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
PROPER USE AND SERVICE PRECAUTIONS 3
SPECIFICATIONS 4
FEATURE DIAGRAM 5
INSTALLATION 6
OPERATION 7
MEASUREMENT OF THE MICROWAVE OUTPUT POWER 8
MICROWAVE RADIATION TEST 9
KOR-6115 WIRING DIAGRAM 10
KOR-61151 WIRING DIAGRAM 11
CIRCUIT DESCRIPTION 12
PRECAUTIONS FOR DISASSEMBLY AND REPAIR 14
DISASSEMBLY AND ASSEMBLY 15
INTERLOCK MECHANISM 20
TROUBLE SHOOTING GUIDE 22
COMPONENT TEST PROCEDURE 24
EXPLODED VIEW AND PARTS LIST 26

3
PROPER USE AND SERVICE PRECAUTIONS
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.
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 even 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 have excessive emission level 5mW/cm
2
, the service person should:
(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 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
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. WAVEGUIDES, FLANGES AND
GASKETS MUST BE SECURE. NEVER OPERATE THE DEVICE WITHOUT A MICROWAVE ENERGY
ABSORBING LOAD ATTACHED. NEVER LOOK INTO AN OPEN WAVEGUIDE OR ANTENNA WHILE THE
DEVICE IS ENERGIZED

4
SPECIFICATIONS
ITEM SPECIFICATION
POWER SUPPLY 120V~60Hz, SINGLE PHASE WITH EARTHING
POWER CONSUMPTION 920 W
MICROWAVE OUTPUT POWER 600 W (IEC 705) (FULL MICROWAVE POWER)
FREQUENCY 2450 MHz
OUTPUT DIMENSIONS (W X H X D) 465 X 274 X 360 mm (18.3 X 10.8 X 14.2 in.)
CAVITY DIMENSIONS (W X H X D) 290 X 200 X 290 mm (11.4 X 7.9 X 11.4 in)
NET WEIGHT APPROX. 12.5 kg (27.6 Ibs.)
TIMER 35 min. DUAL SPEED
POWER SELECTIONS 5 LEVELS
CAVITY VOLUME 0.64 Cu.Ft.
* Specifications are subject to change without notice.
465 360
274

¤Safety Interlock System
¤Ł Door Viewing Screen - Allows viewing of food. The screen is designed so that light can pass through, but not the
microwave.
¤Ø Door Hook - When the door is closed, it will automatically shut. If the door is opened while the oven is operating,
the magnetron will immediately stop operating.
¤Œ Oven Cavity
¤º Door Seal - Door seal maintains the microwave energy within the oven cavity and prevents microwave leakage.
¤Glass Cooking Tray - Made of special heat resistant glass. Food in a proper receptacle is placed on this tray for
cooking.
¤Roller Guide - This must always be used for cooking together with the glass cooking tray.
¤Coupler - This fits over the shaft in the center of the oven’s cavity floor. This is to remain in the oven for all
cooking.
¤Knob V.P.C - Used to select a microwave power level.
¤Knob Timer - Used in setting cooking time for all functions.
¤æ Door Release Button - By pushing this button the latch system cut off all circuits and stops the oven before the
door is opened.
5
FEATURES DIAGRAM
241
11
6
7
8
35
9
12

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 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 or antenna,
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 15 amperes, 120 Volts, 60Hz grounded outlet.
• Power supply cord is about 1.0 meters long.
1. A short power-supply cord is poovided 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,
and (3) the longer cord should be arranged so that will not drape over the countertop or tabletop where it can be
pulled on by children or tripped over unintentionally.
6
Examine the oven after unpacking for any damage such as:
A misaligned door, Broken door, A dents in cavity.
If any of the above are visible, DO NOT INSTALL, and notify dealer immediately.
6
INSTALLATION
When use 3-pronged plug
3-prong Receptacle
Receptacle
Box cover
3-prong plug
When use a grounding adaptor, make
usre the receptacle box is fully
grounded
Grounding Lead
Receptacle Box cover
Grounding Adaptor
Receptacle

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
Choose cooking power by setting V.P.C. Knob to the desired position.
Refer to cookbook for recommended power levels.
5
Determine cooking time. Consult cookbook for recipe timing.
¢”Oven light turns on and cooling fan starts to operate. Microwave cooking starts.
6
You may open the door while the oven is operating.
As soon as the door is opened, the safety mecha-
nisms stop microwave power and cooking timer.
if you wish to change the time during cooking, simply
adjust the Timer to the desired time.
7
When the timer reaches zero, a bell will ring and the
unit will turns off.
¢”Oven light turns off.
If additional cooking time is needed and the door has
not been opened, the oven will automatically start
when the Timer is reset.
7
OPERATION
Variable Power Cooking
ON and OFF cycle time of mechanicial V.P.C. switch is 30 seconds.
When the V.P.C. knob is set to the desired position and timer knob turns to the desired position, the V.P.C. switch
has a cycle (ON/OFF time (sec)) listed below.
NOTE :
1. When setting Timer for less than 2 minutes, turn
the Timer past 2 minutes and then return to the
correct timer setting.
2. Various clicking noises may be heard when turning
the V.P.C. knob. This is normal and does not affect
the operation of your microwave oven.
Variable power setting
(HIGH)
(MED HIGH)
(MEDIUM)
(DEFROST)
(WARM)
ON/OFF time (sec)
30/0
23.2/6.8
16.5/13.5
9.8/20.2
5/25
Power
100%
77%
55%
33%
17%
012
3
4
5
6
10
15
20
25
30
35

Microwave output power can be checked by indirectly measuring 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 1,000¡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).
It 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 49 seconds.
Heating time is measured while the microwave genera-
tor is operating at full power.
The filament heat-up time for magnetrons is not
included.
6. The initial and final water temperatures are selected so
that the maximum difference between the ambient and
final water temperatures is 5K.
7. The microwave power output P in watts is calculated from the following formula:
• ∆T is actual temperature rise.
• t is the heating time.
The power measured should be 600W¡10.0%.
P = 4187 X ∆T/t
8
MEASUREMENT OF THE MICROWAVE OUTPUT POWER
Water Load
Tray
CAUTION :
1. Water load should be measured exactly to 1 liters.
2 Input power voltage should be exactly 230V as specified.
3. Ambient temperature should be 20¡2˚C(68¡3.6˚F)

WARNING
• Make sure to check the microwave leakage before and after repair of adjustment.
• Always, start measuring of an unknown field to assure safety for operating personnel from microwave energy.
• Do not place your hands into any suspected microwave radiation field unless the safe density level is known.
• Care should be taken not to place the eyes in direct line with the source of microwave energy.
• Slowly approach the unit under test until the radiometer reads an appreciable microwave leakage from the unit under the
test.
PROCEDURE
A) Prepare Microwave Energy Survey Meter, 600cc glass beaker, glass thermometer 100˚C or 212˚F.
B) Pour 275cc¡15cc of tap water initially at 20¡5˚C(68¡9˚F) in the 600cc beaker with an inside diameter of approx.
9.5cm (3.5 in).
C) Place it at the center of the tray and set it in a cavity.
D) Close the door and operate the oven.
E) Measure the leakage by using microwave energy survery meter with dual ranges, set to 2450 MHz.
ƒ¡ Measured radiation leakage must not exceed the values prescribed below.
• Leakage for a fully assembled oven with door normally closed must be less than 4mW/cm
2
.
ƒ¡When measuring the leakage, always use the 2 in (5cm) 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 seam, door viewing screen, the
exhaust air vents and the suction air vents.
ƒ¡Measuring should be in a counter-clockwise direc-
tion at a rate of 1 inch/sec. If the leakage of the
cabinet door seam is unknow, move the probe more
slowly.
ƒ¡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 inches from any metal.
If it does, erroneous reading may result.
9
MICROWAVE RADIATION TEST

10
KOR-6115 WIRING DIAGRAM
POWER SUPPLY :
PRIMARY INTERLOCK SWITCH(UPPER)
TIMER SWITCH
TIMER ASS'Y
V.P.C
.
FUSE
INTERLOCK MONITOR SWITCH
HIGH VOLTAGE TRANSFORMER
H.V. CAPACITOR
H.V. DIODE
MAGNETRON
WH
LIVE RD
BK
WH
NEUTRAL
WH
BK
BL
GY
GYGY
GY
GY GY
CL GM FM
SECONDARY INTERLOCK SWITCH
NOTE : RD : RED
WH: WHITE BK : BLACK GN : GREEN BR : BROWN
OR : ORANGE BL : BLUE GY : GRAY GE : GREEN/YELLOW
CL : CAVITY LAMP FM : FAN(BLOWER) MOTOR GM : GEARED MOTOR TM : TIMER MOTOR V.P.C. : VARIABLE POWER CONTROLLER
[ CONDITION ] DOOR : CLOSED TIMER : ON V.P.C. : HIGH
RD RD
OR OR
SINGLE PHASE
~
ONLY
2
M
13
TM
GN