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Daewoo KOR-6QDB Service manual
S/M No. : OR6QDB3001
Service Manual
Microwave Oven
Model : KOR-6QDB
• 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).
Feb. 2008
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 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................................................................................................................................................................4
OUTER DIMENSION.............................................................................................................................................4
FEATURES DIAGRAM..........................................................................................................................................5
CONTROL PANEL ................................................................................................................................................6
INSTALLATION ...................................................................................................................................................................7
OPERATIONS AND FUNCTIONS.......................................................................................................................................8
DISASSEMBLY AND ASSEMBLY......................................................................................................................................9
INTERLOCK MECHANISM AND ADJUSTMENT.............................................................................................................16
TROUBLE SHOOTING GUIDE .........................................................................................................................................17
MEASUREMENT AND TEST ............................................................................................................................................21
MEASUREMENT OF THE MICROWAVE POWER OUTPUT ............................................................................21
MICROWAVE RADIATION TEST .......................................................................................................................22
COMPONENT TEST PROCEDURE ...................................................................................................................23
WIRING DIAGRAM............................................................................................................................................................24
PRINTED CIRCUIT BOARD..............................................................................................................................................25
CIRCUIT CHECK PROCEDURE ........................................................................................................................25
PCB CIRCUIT DIAGRAM....................................................................................................................................28
PCB LOCATION NO ...........................................................................................................................................29
EXPLODED VIEW AND PARTS LIST...............................................................................................................................30
DOOR ASSEMBLY .............................................................................................................................................30
CONTROL PANEL ASSEMBLY..........................................................................................................................30
TOTAL ASSEMBLY.............................................................................................................................................30
1
SAFETY AND 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 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 have excessive emission level 5mW/cm2, 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 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 and CDRH 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 SECURED. NEVER OPERATE THE DEVICE WITHOUT A
MICROWAVE ENERGY ABSORBING LOAD ATTACHED. NEVER LOOK INTO AN OPEN WAVEGUIDE
OR ANTENNA WHILE THE DEVICE IS ENERGIZED.
2
SPECIFICATIONS
POWER SUPPLY
MICROWAVE
120V AC, 60Hz SINGLE PHASE WITH GROUNDING
INPUT POWER
1100 W
ENERGY OUTPUT
700 W
FREQUENCY
2,450MHz
OUTSIDE DIMENSIONS (W
CAVITY DIMENSIONS (W
H
H
D)
D)
465 x 279 x 331 mm (18.3 x 11.0 x 13.0 in.)
301 x 293 x 219 mm (11.9 x 11.5 x 8.6 in.)
CAVITY VOLUME
.68 cu.ft
NET WEIGHT
APPROX. 12 kg (26.54 lbs.)
TIMER
59 min. 99 sec.
POWER SELECTIONS
10 Levels
* Specifications are subject to change without notice.
EXTERNAL VIEW
1. OUTER DIMENSION
465
279
331
3
2. FEATURES DIAGRAM
1
2 3 4
5
0 9
6
8
7
7 Roller guide - This must always be used for
cooking together with the glass cooking tray.
1 Door seal - Door seal maintains the microwave
energy within the oven cavity and prevents
microwave leakage.
8 Glass cooking tray - Made of special heat
resistant glass. Food in a proper receptacle is
placed on this tray for cooking.
2 Oven cavity
3 Safety interlock system
9 Door viewing screen - Allows viewing of food.
The screen is designed so that light can pass
through, but not the microwave.
4 Control panel
5 Door release button - By pushing this button
the latch system cut off all circuits and stops the
oven before the door is opened.
0 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
immediately stop operating.
6 Coupler - This fits over the shaft in the centre of
the ovens cavity floor. This is to remain in the
oven for all cooking.
4
3. CONTROL PANEL
q
e
w
r
t
y
0
u
i
p
o
a
0 Time set pad-Used to set the cooking time and the
present time.
y Power-Used to set power level.
u Defrost-Used to defrost foods.(for time)
q Display-Cooking time, power level, indicators and
present time are displayed.
i Kitchen Timer-Used as a minute timer, to delay the
start of cooking, or to set a holding time after
cooking.
w One touch-Used to cook or reheat specific
quantities of food.
o Clock-Used to set clock.
e More-Used to add time to cooking.
p Stop/Clear-Used to stop the oven operation or to
delete the cooking data.
r Less-Used to remove time from cooking.
t Auto Defrost-Used to defrost foods.(for weight)
a Start/Speedy cook-Used to start the oven and also
used to set a reheat time.
5
INSTALLATION
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 9 amperes, 120Volts, 60Hz grounded outlet.
Line fuse rating is 15 amperes and described on EXPLODED VIEW AND PART LIST.
Power supply cord is about 0.8 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.
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 a dealer immediately.
6
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 open button on the control panel.
The oven will automatically shut off. To restart the oven, close the door and then touch the START pad.
5. Each time a pad is touched, a BEEP will sound to acknowledge the touch.
6. The oven automatically cooks 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.
Make sure the oven is properly installed and plugged into the electrical outlet.
Wattage output chart
The power level is set by touching the POWER pad. The chart shows the display, the power level and the percent age of power.
Touch the 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%
7
DISASSEMBLY AND ASSEMBLY
Cautions to be observed when troubleshooting.
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 with 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 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.
Check continuity of the monitor circuit.
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 a care of touching or replacing high potential parts because of
electric shock or exposing microwave. These parts are as follows - HV Transformer, Magnetron,
HV Capacitor, HV Diode HV Fuse.
8
1. To remove cabinet
1) Remove three screws on cabinet back.
2) Pull 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.
9
3. To remove door parts.
DOOR ASSEMBLY : 3511725360
REF NO.
PART CODE
PART NAME
DESCRIPTION
A01
3512208530
FRAME DOOR
HIPS SG-970, HG-176OH
1
A02
3517007300
BARRIER-SCREEN *O
PET T0.125
1
A03
3515204100
STOPPER HINGE *T AS
KOR-63150S
1
A04
3511719500
DOOR PAINTING AS
KOR-6C0B5S
1
A05
3517002800
BARRIER SCREEN *I
POLYESTER TO.1
1
A06
3512300210
GASKET DOOR
PP
1
A07
3513100700
HOOK
POM
1
A08
3515101300
SPRING HOOK
PW1
1
(1) Remove the gasket door from door painting as.
(2) Remove the door frame from door painting as.
(3) Remove the stopper hinge top from door painting as.
(4) Remove the spring and the hook.
(5) Remove the barrier screen outer from door frame.
(6) Reverse the above steps for reassembly.
10
Q'TY
REMARK
4. Method to reduce the gap between the door seal and the oven front surface.
(1) To reduce gap located on part ‘A’
• Loosen two screws on the stopper hinge top, and
then push the door to contact the door seal to the
oven front surface.
• Tighten two screws.
A
C
B
D
(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.
NOTE : A small gap may be acceptable if the microwave leakage does not exceed 4mW/cm2.
11
5. To remove control panel parts.
CIPANEL ASSEMBLY : PKCPSW140
REF NO.
PART CODE
PART NAME
DESCRIPTION
Q’TY
B01
351857183O
SWITCH MEMBRANE
KOG-6QDB3A27
1
B02
3516733340
CONTROL-PANEL
HIPS
1
B03
PKMPMSBA4
PCB ASSY.
KOG-6QDB3A27
1
B04
7122401211
SCREW TAPPING
T2S TRS 4X12 MFZN
4
B05
3513702700
LEVER DOOR OPEN
PP
1
B06
3516915210
BUTTON DOOR OPEN
HIPS SG-970, HG-176OH
1
B07
441G430171
SPRING BUTTON
SWP DIA. 0.7
1
REMARK
(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.
12
6. To remove high voltage capacitor.
1) Remove the 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 the 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.
13
8. To remove wind guide assembly.
1) Remove the screw which secure the wind guide assembly.
2) Draw forward the wind guide assembly.
3) Pull the fan from the motor shaft.
4) Remove two screws which secure the motor shaded pole.
5) Remove the motor shaded pole.
6) 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.
14
INTERLOCK MECHANISM AND ADJUSTMENT
The door lock mechanism is a device which has been specially designed to completely eliminate microwave radiation when
the door is opened during operation, and thus to perfectly prevent the danger resulting from the leakage of microwave.
(1) Primary interlock switch
When the door is closed, the hook locks the oven door. If the door is not closed properly, the oven will not operate.
When the door is closed, the hook pushes the button of the microswitch. Then the button of the primary interlock switch
bring it under ON condition.
(2) Secondary interlock switch and interlock monitor switch
When the door is closed, the hook pushes the lock lever downward. The lock lever presses the button of the interlock
monitor switch to bring it under OFF condition and presses the button of the secondary interlock switch to bring it under
ON condition.
ADJUSTMENT :
Interlock monitor switch
When the door is closed, the interlock monitor switch should be "OFF" condition before other switches are "ON" condition.
When the door is opened, the interlock monitor switch should be "ON" condition after other switches are "OFF" condition.
(3) Adjustment steps
a) Loosen the mounting screw.
b) Adjust interlock switch assembly position.
Actuation distance of primary and secondary interlock switch shall be adjusted almost 0.7mm.
c) Make sure that lock lever moves smoothly after adjustment is completed.
d) Tighten completely a mounting screw.
NOTE :
Microwave emission test should be performed after adjusting interlock mechanism. If the microwave emission exceed
4mW/cm2, readjust interlock mechanism.
15
TROUBLESHOOTING 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 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 harness, 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
RESULT
Check continuity of interlock
monitor switch with door closed
Continuity
Fuse blows.
CAUSE
Malfunction of
interlock
monitor switch
REMEDY
Replace
(NOTE 1)
No Continuity
Replace fuse
Check continuity of of primary
interlock switch contact with door
partially open until interlock
monitor switch contact close
Continuity
Shorted
contacts of
primary
interlock switch.
Replace
(NOTE 1)
No Continuity
Check continuity of primary
winding of low voltage
transformer
Disconnect one side of the lead
wire connected form high
voltage transformer to the high
voltage capacitor and operate
the unit
0Ω or infinite
Approx.
150~310
(normal)
Normal
Fuse again
blows
16
Defective low
voltage
transformer
Defective high
voltage capacitor
Defective high
voltage
transformer
Replace
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
power supply cord
No
Continuity
Open power
supply cord
Replace
Normal
Defective touch
control circuit
Replace
Malfunction of
secondary
interlock switch
Replace
Display do not shown
countdown
NOTE 1
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 the START pad is touched.
CONDITION
CHECK
RESULT
CAUSE
REMEDY
Turn table
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 switch
No
Continuity
Malfunction of
secondary
interlock
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
17
Replace
(TROUBLE 3)
CONDITION
No
microwave
oscillation
No microwave oscillation even though fan motor rotates.
CHECK
RESULT
CAUSE
REMEDY
Check continuity of 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
Check continuity of magnetron
with wires removed
Check continuity of filament
terminal of high voltage
transformer
No
Continuity
No
Continuity
Defective
magnetron
Defective high
voltage
transformer
0V
Check D.C. voltage being
supplied to RELAY (RY1) coil
Defective touch
control circuit
Approx
15 VDC
18
Faulty
contacts or
RELAY (RY1)
or open
relay coil
Replace
Replace
Replace
Replace
(TROUBLE 4)
The following visual conditions indicate a probable defective touch control circuit or membrane switch
assembly.
1. Incomplete segments
(1) Segments missing
(2) Partial segments missing
(3) Digit flickering other than normal display slight flickering
(4) :0 does not display when power is on.
2. A distinct change in the display are not on when they numbers is the
display.
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 noticeably too fast while cooking.
10. Display does not show the time of day when STOP/CLEAR pad is touched. (in case of setting the present time)
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
CAUSE
REMEDY
Normal
Malfunction
of control circuit
board
Replace
control circuit
board
Abnormal
Malfunction
of the membrane
keyboard
Replace the
membrane
keyboard
NOTE
Before following the particular steps listed above in the troubleshooting guide for the membrane keyboard’s
failure, please check for the continuity of each wire-harness between the membrand keyboard and P.C.B.
assembly.
19
MEASUREMENT AND TEST
1. MEASUREMENT OF THE MICROWAVE POWER OUTPUT
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 1000 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 A seconds. (Refer to table as following)
Heating time is measured while the microwave generator is operating at full power.
The filament heat-up 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 should be B (Refer to SPECIFICATIONS)W 10.0%.
CAUTION :
1. Water load should be measured exactly to 1 liter.
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
20
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.
PROCEDURES
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 600cc glass beaker with an inside diameter of approx.
85mm(3.5in.).
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 5cm(2in.)
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.
21
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
10%
Filament winding
Approx. 0
Primary winding
Approx. 1
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 10M once the capacitor is charged.
(3) A shorted capacitor will show continuous continuity.
(4) An open capacitor will show constant 10M .
(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 A normal diode s resistance will be infinite in one direction and
several hundred K 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 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.
6. Interlock switches
(1) You can test continuity of safety interlock and monitor switch by using ohmmeter.
(2) The switch operation is checked by zero/unlimited.
The meter should indicate zero resistance.
(3) The sequence of check is interlock monitor switch, primary and secondary interlock switches check.
22
WIRING DIAGRAM
23
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 : 120V/Frequency : 60Hz
Terminal Voltage
5-6-7
LOAD
AC 12.6 V
NO LOAD
AC 14.7 V
NOTE :
1. Refer to Circuit 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 POINT
1
IC 1 PIN 5
2
IC 1 PIN 8
REMARK
5 VDC
T:16.67ms(60Hz)
3
IC 1 PIN 35 OR PIN 36
T:250ns(4MHz)
Check method
NO
MEASURE POINT
1
MP1
2
MP2
WAVE FORM
REMEDY
REMARK
DC 5V 0.25V
Replace VL1, EC1
NO LOAD
DC 12V 2.0V
Replace EC2, D11, D13, D14
NO LOAD
NOTE :
Each measure point must be measured with GND point.
24
MP1
MP2
GND
Measure Point
25
3. When there is no microwave oscillation
1) When touching START pad, oven lamp does not turn on.
Fan motor does not rotate, but cook indicator in display comes on.
B
A
RY2
42
D10
(TRAY
LAMP)
Q10
RY2
- Check method
POINT
A
B
RELAY 2 ON
5VDC
GND
RELAY 2 OFF
GND
12VDC
STATE
2) When touching START pad, oven lamp turns on.
Fan motor and turntable rotate and cook indicator in display comes on.
B
A
RY1
41
D8
(M/W)
Q9
RY1
- Check method
POINT
A
B
RELAY 1 ON
5VDC
GND
RELAY 1 OFF
GND
12VDC
STATE
4. When the door is opened during operation, the count down timer does not stop.
A
B
R1
CN1
1
2
27
R10
C1
D.O.M SW
R9
C2
+5V
-Check method
POINT
A
B
1) DOOR OPEN
OPEN
5VDC
2) DOOR CLOSED
CLOSE
GND
STATE
CHECK NO
1
METHOD
REMEDY
Check the stage (ON, OFF) of the door open monitor switch by
resistance measurement.
5. When the digital clock does not operate properly.
Refer to Circuit Diagram.
POINT
WAVE FORM
IC 1 PIN 8
T:16.67ms(60Hz)
* If clock does not keep exact time, you must check resistor R20 and zener diode ZD2.
26
Replace door open monitor
switch.
2. PCB CIRCUIT DIAGRAM
27
3. PCB LOCATION NO.
NO
NAME
SYMBOL
SPECIFICATION
PART CODE
Q'TY REMARK
1
BUZZER
BZ1
BM-20K (BUJEON)
3515600100
1
2
C ARRAY
CA1
7P(6) 1000PF M 50V 2.54MM
CN6XB-102M
1
3
CONN WAFER
CN1
YW396-02V(YEONHO)
3519150520
1
4
CONN FILM
CN2
FCZ 254-11(YEON HO)
441M367160
1
5
CONN WAFER
CN3
YW396-05AV(YEONHO)
3519150510
1
6
LED DISPLAY
DP1
LTC-4651HG(631)
DDDG631H02
1
7
C ELECTRO
EC2
25V RSS 1000MF (13X20) TP
CEXF1E102V
1
8
IC MICOM
IC1
HMS81C1708B-HN017-1
150SR6N6Q-
1
9
TRANS POWER
LVT1
DMR-631P
5EPU035302
1
10
SW RELAY
RY1
G5G-1A 1C 1P DC12V
5SC0101121
1
11
SW RELAY
RY2
CS11-12SH 1C 1P
5SC0101128
1
12
WIRE COPPER
SJ1~2,4~5
1/0.52 TIN COATING
85801052GY
4
13
IC REGULATOR
VL1
MC7805C(S/S)
1CPMC7805C
1
14
RESONATOR CERA
CR1
CRT 4.00MS
5P4R00MTS-
1
15
C ELECTRO
EC1
50V RS 10MF (5X11) TP
CEXE1H100A
1
16
TR
Q01~5
KRA106M(AUTO)
TZRA106M--
5
17
TR
Q06
KTA1266Y- (AUTO)(1015Y)
TZTA1266Y-
1
18
TR
Q09~11
KRC106M(AUTO)
TZRC106M--
3
19
R ARRAY
RA1
8P(7) 1/8 100K OHM J
RA-88X104J
1
20
R ARRAY
RA2
7P(6) 1/8 100K OHM J
RA-87X104J
1
21
PCB MAIN
BOARD
M158-1
3514315411
1
22
C CERA
C01~4,6~7
HIKF 50V 0.1MF Z AXIAL
CCZF1H104Z
6
23
C CERA
C05
50V B 1000PF K (AXIAL)
CCZB1H102K
1
24
DIODE
D01~5,8~12
1N4148 AUTO 52MM
DZN4148---
10
25
DIODE
D13~14
KN4004A AUTO 52MM
DZN4004A--
2
26
WIRE COPPER
J01~10,13~14
1/0.52 TIN COATING
85801052GY
12
7.5mm
27
WIRE COPPER
J11~12
1/0.52 TIN COATING
85801052GY
2
10.0mm
28
R CARBON FILM
R01,10,12,17,18,22 1/6 1K OHM J
RD-AZ102J-
6
29
R CARBON FILM
R02~8
1/6 330 OHM J
RD-AZ331J-
7
30
R CARBON FILM
R09
1/6 100K OHM J
RD-AZ104J-
1
31
R CARBON FILM
R11
1/6 200 OHM J
RD-AZ201J-
1
32
R CARBON FILM
R13,19~20
1/6 10K OHM J
RD-AZ103J-
3
33
R CARBON FILM
R14
1/6 1M OHM J
RD-AZ105J-
1
34
R CARBON FILM
R21
1/4 51 OHM J
RD-4Z510J-
1
35
DIODE ZENER
ZD1
UZ-3.3BSB(3.32-3.53V)
DZUZ3R3BSB
1
36
DIODE ZENER
ZD2
UZ-5.1BSB(4.97-5.18V)
DZUZ5R1BSB
1
28
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
29
REF NO
A00
B00
F01
F02
F03
F04
F05
F06
F07
F08
F09
F10
F11
F12
F13
F14
F15
F16
F17
F18
F19
F20
F21
F22
F23
F24
F25
F26
F27
F28
F29
F30
F31
F32
F33
F34
F35
F36
F37
F38
F39
F40
F41
F42
F43
F44
PART CODE
3511725360
PKCPSWF300
3510808400
3516004100
3516117400
3518902600
7121300611
7122401211
7122401211
7S312X40A1
35113NKX55
7122401211
7121402511
3963821620
3512517000
3511800300
3518003410
3516004000
7S432X4081
3513003200
3518301600
3518400900
3518122900
3516003700
3510316000
7S312X40A1
3512100900
7S432X4081
3515201101
4417B07600
3511100800
3512781440
4415A17352
4415A66600
4415A17352
3513702600
3513815810
3513601500
7S312X40A1
3966821600
7272400811
3511406220
3517400600
3514700710
3512517300
3517203600
PART NAME
DOOR AS
CONTROL-PANEL AS
CABINET AS
SPECIAL SCREW
CAVITY AS
THERMOSTAT
SCREW TAPPING
SCREW TAPPING
SCREW TAPPING
SCREW SPECIAL
CORD POWER AS
SCREW TAPPING
SCREW TAPPING
MOTOR SHADED POLE
GUIDE WIND
FAN
MAGNETRON
SPECIAL SCREW
SPECIAL SCREW
HOLDER HV CAPACITOR
CAPACITOR HV
DIODE HV AS
TRANS HV
SPECIAL SCREW
BASE
SCREW SPECIAL
FOOT
SPECIAL SCREW
STOPPER HINGE *U
FUSE CERA
CASE FUSE
HARNESS MAIN
SW MICRO
SW MICRO
SW MICRO
LEVER LOCK
LOCK
LAMP
SCREW SPECIAL
MOTOR SYNCRO
SCREW TAPTITE
COVER WAVE GUIDE
COUPLER
ROLLER
GUIDE ROLLER
TRAY
DESCRIPTION
KOR-6QDB3S
KOR-6QDB3A27
KOR-6NM51A
T1 TRS LR4 POLE 4X10 MFZN
KOR-6NM51A
OFF:90 ON:60 H #187
T2S PAN 3X6 MFZN
T2S TRS 4X12 MFZN
T2S TRS 4X12 MFZN
T1 TRS 4X10 SE MFZN
3X18AWG 40X80 110-RTML 600W ONLY
T2S TRS 4X12 MFZN
T2S PAN 4X25 MFZN
120V 60HZ MW08XA-M01
PP
PP+30%GLASS
RM228JF 5CF
T2 BOLT FLANGE 5X12 DACRO
TT3 TRS 4X8 SE MFZN
SECC T0.5
2100VAC 0.77UF #187 65MM
HVR-1X-30B #187
DWAR70A0-63T A (AL/AL)
TT3 HEX 4X8 FLG MFZN
SBHG 0.7T
T1 TRS 4X10 SE MFZN
PP DASF-130
TT3 TRS 4X8 SE MFZN
SCP-1 T2.5
UL/CSA MF61 15A 250V TL
GS12000
KOR-6NBG3A
VP-533A-OF SPNO #187 200G
VP-532A-OF SPNC #187 200G
VP-533A-OF SPNO #187 200G
POM
PP(GRAY) TB53
BL 125V 25W T25 C5A H187
T1 TRS 4X10 SE MFZN
120V 60HZ ST-16 KX63MQAD A
TT3 TRS 4X8 MFZN
PP J640A WHITE
XAREC
TEFLON
PP 5113MF6 A353B
GLASS
30
Q'TY
1
1
1
3
1
1
1
1
1
1
1
1
2
1
1
1
1
1
1
1
1
1
1
4
1
5
2
1
1
1
1
1
1
1
1
1
1
1
1
1
2
1
1
3
1
1
DAEWOO ELECTRONICS CORP.
686, AHYEON-DONG MAPO-GU SEOUL, KOREA
C.P.O. BOX 8003 SEOUL, KOREA
TELEX: DWELEC K28177-8
CABLE: “DAEWOOELEC”
S/M NO. :
PRINTED DATE: Feb. 2008
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