MICROWAVE OVEN
MG1480STB
SERVICE
MICROWAVE OVEN
Manual
CONTENTS
1. Precaution
2. Specifications
3. Operating Instructions
4. Disassembly and Reassembly
5. Alignment and Adjustments
6. Trouble shooting
7. Exploded Views and Parts List
8. PCB Diagrams
9. Schematic Diagrams
SEM
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.
1. Precaution
Follow these special safety precautions. Although the microwave oven is completely safe during ordinary use,
repair work can be extremely hazardous due to possible exposure to microwave radiation, as well as potentially
lethal high voltages and currents.
1-1 Safety precautions (
)
1. All repairs should be done in accordance
with the procedures described in this
manual. This product complies with
Federal Performance Standard 21 CFR
Subchapter J(DHHS).
11. To avoid any possible radiation hazard,
replace parts in accordance with the wiring
diagram. Also, use only the exact
replacements for the following parts:
Primary and secondary interlock switches,
interlock monitor switch.
2. Microwave emission check should be
performed to prior to servicing if the oven is
operative.
12. If the fuse is blown by the Interlock Monitor
Switch: Replace all of the following at the
same time: Primary, door sensing switch
and power relay, as well as the Interlock
Monitor Switch. The correct adjustment of
these switches is described elsewhere in
this manual. Make sure that the fuse has the
correct rating for the particular model being
repaired.
3. If the oven operates with the door open :
Instruct the user not to operate the oven and
contact the manufacturer and the center for
devices and radiological health immediately.
4. Notify the Central Service Center if the
microwave leakage exceeds 5 mW/cm2.
13. Design Alteration Warning:
Use exact replacement parts only, i.e.,
only those that are specified in the
drawings and parts lists of this manual.
This is especially important for the
Interlock switches, described above.
Never alter or add to the mechanical or
electrical design of the MWO. Any design
changes or additions will void the
manufacturer's warranty. Always unplug
the unit's AC power cord from the AC
power source before attempting to
remove or reinstall any component or
assembly.
5. Check all grounds.
6. Do not power the MWO from a "2-prong"
AC cord. Be sure that all of the built-in
protective devices are replaced. Restore any
missing protective shields.
7. When reinstalling the chassis and its
assemblies, be sure to restore all protective
devices, including: nonmetallic control
knobs and compartment covers.
14. Never defeat any of the B+ voltage
interlocks. Do not apply AC power to the
unit (or any of its assemblies) unless all
solid-state heat sinks are correctly installed.
8. Make sure that there are no cabinet openings
through which people --particularly
children --might insert objects and contact
dangerous voltages. Examples: Lamp hole,
ventilation slots.
15. Some semiconductor ("solid state") devices
are easily damaged by static electricity.
Such components are called
Electrostatically Sensitive Devices (ESDs).
Examples include integrated circuits and
field -effect transistors.
Immediately before handling any
semiconductor components or assemblies,
drain the electrostatic charge from your
body by touching a known earth ground.
9. Inform the manufacturer of any oven found
to have emission in excess of 5 mW/cm2 ,
Make repairs to bring the unit into
compliance at no cost to owner and try to
determine cause.
Instruct owner not to use oven until it has
been brought into compliance.
16. Always connect a test instrument's ground
lead to the instrument chassis ground before
connecting the positive lead; always remove
the instrument's ground lead last.
CENTRAL SERVICE CENTER
10. Service technicians should remove their
watches while repairing an MWO.
-1-
1-2 Special Servicing Precautions (Continued)
17. When checking the continuity of the witches
or transformer, always make sure that the
power is OFF, and one of the lead wires is
disconnected.
18. Components that are critical for safety are
indicated in the circuit diagram by
shading,
or .
19. Use replacement components that have the
same ratings, especially for flame resistance
and dielectric strength specifications. A
replacement part that does not have the
same safety characteristics as the original
might create shock, fire or other hazards.
1-3 Special High Voltage Precautions
H. V. Capacitor
1. High Voltage Warning
Do not attempt to measure any of the high
voltages --this includes the filament voltage
of the magnetron. High voltage is present
during any cook cycle.
Before touching any components or wiring,
always unplug the oven and discharge the
high voltage capacitor (See Figure 1-1)
2. The high-voltage capacitor remains charged
about 30 seconds after disconnection. Short
the negative terminal of the high-voltage
capacitor to to the oven chassis. (Use a
screwdriver.)
H. V. Diode
3. High voltage is maintained within specified
limits by close-tolerance, safety-related
components and adjustments. If the high
voltage exceeds the specified limits, check
each of the special components.
Short
Touch chassis ground first then short to the high
voltage capacitor terminal by using screwdriver or
jumper wire.
Fig. 1-1 Discharging High Voltage Capacitor
PRECAUTION
Never touch any circuit wiring with your hand
nor with uninsulated tool during operation.
PRECAUTION
There exists HIGH VOLTAGE ELECTRICITY
with high current capabilities in the circuits of the
HIGH VOLTAGE TRANSFORMER secondary
and filament terminals. It is extremely dangerous
to work on or near these circuits with the oven
energized.
DO NOT measure the voltage in the high voltage
circuit including filament voltage of magnetron.
PRECAUTION
Servicemen should remove their watches
whenever working close to or replacing the
magnetron.
-2-
2. Specifications
2-1 Table of Specifications
TIMER
99 MINUTES 99 SECONDS
POWER SOURCE
120V60Hz, AC
POWER CONSUMPTION
MICROWAVE : 1,500W
GRILL : 1,300W
OUTPUT POWER
950W
(IEC-705 TEST PROCEDURE)
OPERATING FREQUENCY
2,450MHz
MAGNETRON
OM75P(31)ESS
COOLING METHOD
COOLING FAN MOTOR
OUTSIDE DIMENSIONS
555(W) x 313(H) x 464(D)mm
NET WEIGHT
18.5 kg
SHIPPING WEIGHT
21.0 kg
-3-
3. Operating Instructions
3-1 Control Panel
3-2 Features & External Views
VENTILATION HOLES
GRILL
LIGHT
DOOR LATCHES
OPEN DOOR
PUSH BUTTON
COUPLER
SAFETY
INTERLOCK HOLES
TURNTABLE
313mm
DOOR
555mm
464mm
-4-
4. Disassembly and Reassembly
4-1 Replacement of Magnetron, Motor Assembly and Lamp
Cover Air
Remove the magnetron including the shield case,
permanent magnet, choke coils and capacitors
(all of which are contained in one assembly).
Lamp
Thermo S/W
Bracket
T.C.O
1. Disconnect all lead wires from the magnetron
and lamp.
2. Remove a screw securing air cover.
3. Remove the air cover.
4. Remove screws securing the magnetron to the
wave guide.
5. Take out the magnetron very carefully.
6. Remove nuts from the back panel.
7. Take out the fan motor.
8. Remove the oven lamp by rotating to pull out
from hole of air cover.
Magnetron
Screws
NOTE1: When removing the magnetron, make
sure that its antenna does not hit any
adjacent parts, or it may be damaged.
H.V.Trans
Magnetron
Fan Motor
H.V.Capacitor
NOTE2: When replacing the magnetron, be sure
to remount the magnetron gasket in the
correct position and make sure the
gasket is in good condition.
4-2 Replacement of High Voltage Transformer
1.
2.
3.
4.
Discharge the high voltage capacitor.
Disconnect all the leads.
Remove the mounting bolts.
Reconnect the leads correctly and firmly.
PRECAUTION
Servicemen should remove their watches whenever
working close to or replacing the magnetron.
PRECAUTION
There exists HIGH VOLTAGE ELECTRICITY with high current capabilities in the circuits of the HIGH
VOLTAGE TRANSFORMER secondary and filament terminals. It is extremely dangerous to work on or near
these circuits with the oven energized.
DO NOT measure the voltage in the high voltage circuit including filament voltage of magnetron.
-5-
4-3 Replacement of Door Assembly
4-3-1 Removal of Door Assembly
Remove hex bolts securing the upper hinge and
lower hinge. Then remove the door assembly.
Upper Hinge
Screw
Lower Hinge
4-3-2 Removal of Door "C"
Screw
Insert flat screwdriver into the gap between Door
"A" and Door "C" to remove Door "C". Be careful
when handling Door "C" because it is fragile.
Then remove the door assembly.
4-3-3 Removal of Door "E"
Door "E"
Following the procedure as shown in the figure,
insert and bend a thin metal plate between Door
"E" and Door "A" until you hear the 'tick' sound.
1. Insertion depth of the thin metal plate should be
0.5mm or less.
4-3-4 Removal of Key Door & Spring
Remove pin hinge from Door "E"
Detach spring from Door "E" and key door.
Door "E"
Key Door
-6-
Spring
4-3-5 Reassembly Test
After replacement of the defective component parts of the door, reassemble it and follow the instructions
below for proper installation and adjustment so as to prevent an excessive microwave leakage.
1. When mounting the door to the oven, be sure to adjust the door parallel to the bottom line of the oven
face plate by moving the upper hinge and lower hinge in the direction necessary for proper alignment.
2. Adjust so that the door has no play between the inner door surface and oven front surface. If the door
assembly is not mounted properly, microwave energy may leak from the space between the door and oven.
3. Do the microwave leakage test.
4-4 Replacement of Fuse
1. Disconnect the oven from the power source.
2. When 15A fuse blows out by the operation of interlock monitor switch failure, replace the primary interlock
switch, door sensing switch, monitor switch and power relay.
3. When the above three switches operate properly, check if any other part such as the control circuit board,
blower motor or high voltage transformer is defective.
4-5 Replacement of Drive Motor
1. Take out the glass tray, guide roller and coupler
from cavity.
2. Turn the oven upside down to replace the drive motor.
3. Remove a screw securing the drive motor cover.
4. Disconnect all the lead wires from the drive motor.
5. Remove screws securing the drive motor to the cavity.
6. Remove the drive motor.
7. When replacing the drive motor, be sure to
remount it in the correct position.
8. Connect all the leads to the drive motor.
9. Screw the drive motor cover to the base plate
with a screw driver.
10. Remount the coupler in the correct position.
Screw
Drive Motor
Base Plate
Drive Motor Cover
-7-
4-6 Replacement of Control Circuit Board
4-6-1 Removal of Control Box
1. Be sure to ground any static electric charge in
your body and never touch the control circuit.
2. Disconnect the connectors from the control
circuit board.
Screw
3. Remove screws securing the control box
assembly.
4. Remove the screw securing the ground tail of
the keyboard.
Control Box
4-6-2 Removal of P.C.B Assembly
1. Pull the lever end of the plastic fastener and
remove the Flexible Printed Circuit(FPC) of
membrane panel.
ASSY PCB
2. Remove screws securing the control circuit
board.
SCREWS
3. Lift up the control circuit board from the Ass'y
control box.
4. When reconnecting the FPC connector, make
sure that the holes on the connector are properly
engaged with the hooks on the Plastic Fastener.
4-6-3 Removal of Window Display & Membrane Panel
1. Window display should not be disassembled as
its mounting tabs will be broken. If repair work
is difficult, replace with Ass'y control panel.
Window Display
2. The membrane key board is attached to the
escutcheon base with double faced adhesive
tape. Therefore, applying hot air such as using of
hair dryer is recommended for smoother
removal.
3. When installing new membrane key board, make
sure that the surface of escutcheon base is
cleaned sufficiently so that any problems
(shorted contacts or uneven surface) can be
avoided.
Membrane Panel
-8-
5. Alignment and Adjustments
PRECAUTION
1. High voltage is present at the high voltage terminals during any cook cycle.
2. It is neither necessary nor advisable to attempt measurement of the high voltage.
3. Before touching any oven components or wiring, always unplug the oven from its power source and
discharge the high voltage capacitor.
5-1 High Voltage Transformer
1. Remove connectors from the transformer terminals
and check continuity.
2. Normal resistance readings are as follows:
MODEL
Filament Terminals
SHV-U11KA
Secondary
78.0Ω ± 10%
Filament
Shows Continuity
Primary
0.31Ω ± 10%
Primary
Terminals
(Room temperature = 20° C)
Secondary
Terminal
5-2 Low Voltage Transformer
1. The low voltage transformer is located on the
control circuit board.
2. Remove the low voltage transformer from the
PCB Ass'y and check continuity.
3. Normal resistor reading is shown in the table.
Resistance
Terminals
1~2(Input)
SLV-4290U
379Ω
4~5(Output17V)
10.23Ω
7~8(Output2.7V)
31.91Ω
5-3 Magnetron
1. Continuity checks can indicate only an open
filament or a shorted magnetron. To diagnose an
open filament or shorted magnetron :
2. Isolate the magnetron from the circuit by
disconnecting its leads.
3. A continuity check across the magnetron filament
terminals should indicate one ohm or less.
4. A continuity check between each filament terminal
and magnetron case should read open.
Magnetron Antenna
Cooling Fins
-9-
Gasket Plate
5-4 High Voltage Capacitor
1.
2.
3.
4.
5.
Check continuity of the capacitor with the meter set at the highest resistance scale.
Once the capacitor is charged, a normal capacitor shows continuity for a short time, and then indicates 9MΩ.
A shorted capacitor will show continuous continuity.
An open capacitor will show constant 9MΩ.
Resistance between each terminal and chassis should read infinite.
5-5 High Voltage Diode
1. Isolate the diode from the circuit by disconnecting its leads.
2. With the ohm-meter set at the highest resistance scale, measure across the diode terminals. Reverse the
meter leads and read the resistance. A meter with 6V, 9V or higher voltage batteries should be used to
check the front-to back resistance of the diode (otherwise an infinite resistance may be read in both
directions). The resistance of a normal diode will be infinite in one direction and several hundred KΩ in the
other direction.
5-6 Main Relay and Power Control Relay
1. The relays are located on the PCB Ass'y. Isolate them from the main circuit by disconnecting the leads.
2. Operate the microwave oven with a water load in the oven. Set the power level set to high.
3. Check continuity between terminals of the relays after the start pad is pressed.
5-7 Adjustment of Primary Switch, Door Sensing Switch and Monitor Switch
Precaution
For continued protection against radiation hazard, replace parts in accordance with the wiring diagram and be sure to
use the correct part number for the following switches: Primary and secondary interlock switches, and the interlock
monitor switch (replace all together). Then follow the adjustment procedures below. After repair and adjustment, be
sure to check the continuity of all interlock switches and the interlock monitor switch.
1. When mounting Primary switch and Interlock
Monitor switch to Latch Body, consult the figure.
2. No specific adjustment during installation of
Primary switch and Monitor switch to the latch
body is necessary.
3. When mounting the Latch Body to the oven
assembly, adjust the Latch Body by moving it so
that the oven door will not have any play in it.
Check for play in the door by pulling the door
assembly. Make sure that the latch keys move
smoothly after adjustment is completed.
Completely tighten the screws holding the Latch
Body to the oven assembly.
Primary Interlock
Switch
Body Latch
Interlock Monitor
Switch
4. Reconnect to Monitor switch and check the
continuity of the monitor circuit and all latch
switches again by following the components test
procedures.
Lever Switch
Door Sensing
Switch
5. Confirm that the gap between the switch
housing and the switch actuator is no more than
0.5mm when door is closed.
6. Interlock Switch Replacement - When
replacing faulty switches, be sure switch mounting
tabs are not bent, broken or otherwise deficient in
their ability to secure the switches in place.
Door Open
Door Closed
Primary switch
∞
0
Monitor switch(COM-NC)
0
∞
Door Sensing S/W
∞
0
- 10 -
5-8 Output Power of Magnetron
CAUTION
MICROWAVE RADIATION
PERSONNEL SHOULD NOT ALLOW EXPOSURE TO MICROWAVE RADIATION FROM MICROWAVE
GENERATOR OR OTHER PARTS CONDUCTING MICROWAVE ENERGY.
The output power of the magnetron can be measured by performing a water temperature rise test.
Equipment needed :
* Two 1-liter cylindrical borosilicate glass vessel (Outside diameter 190 mm)
* One glass thermometer with mercury column
NOTE: Check line voltage under load. Low voltage will lower the magnetron output. Make all temperature
and time tests with accurate equipment.
1. Fill the one liter glass vessel with water.
2. Stir water in glass vessel with thermometer, and record glass vessel's temperature ("T1", 10±1° C).
3. After moving the water into another glass vessel, place it in the center of the cooking tray. Set the oven to
high power and operate for 47seconds exactly. (3 seconds included as a holding time of magnetron
oscillation:)
4. When heating is finished, stir the water again with the thermometer and measure the temperature ("T2").
5. Subtract T1 from T2. This will give you the water temperature rise. (△T)
6. The output power is obtained by the following formula;
Output Power =
4.187 x 1000 x △T+0.88xMcx(T2 -T0)
44
44 : Heating Time (sec)
4.187 : Coefficient for Water
1000 : Water (cc)
△T : Temperature Rise (T2-T1)
To : Room Temperature
Mc : Cylindrical borosilicate glass weight
7. Normal temperature rise for this model is 9°C to 11° C at 'HIGH'.
NOTE 1: Variations or errors in the test procedure will cause a variance in the temperature rise.
Additional power test should be made if temperature rise is marginal.
NOTE 2: Output power in watts is computed by multiplying the temperature rise (step 5) by a factor of 91
times the of centigrade temperature.
5-9 Microwave Heat Distribution - Heat Evenness
The microwave heat distribution can be checked indirectly by measuring the water temperature rise at
certain positions in the oven:
1. Prepare five beakers made of 'Pyrex', having 100 milliliters capacity each.
2. Measure exactly 100milliliters off water load with a measuring cylinder, and pour into each beaker.
3. Measure the temperature of each water load. (Readings shall be taken to the first place of decimals.)
4. Put each beaker in place on the cooking tray as illustrated in figure below. Start heating.
5. After heating for 2minutes, measure the water temperature in each beaker.
6. Microwave heat distribution rate can be calculated as follows:
Heat Distribution =
Minimum
Temperature Rise
Maximum
Temperature Rise
D
X 100(%)
The result should exceed 65%.
D/4
D/4
D/4
D/4
- 11 -
Beaker
D
Cooking Tray
5-10 Procedure for Measurement of Microwave Energy Leakage
1) Pour 275±15cc of 20±5° C(68±9° F) water in a beaker
which is graduated to 600cc, and place the beaker in
the center of the oven.
2) Start to operate the oven and measure the leakage by
using a microwave energy survey meter.
3) Set survey meter with dual ranges to 2,450MHz.
4) When measuring the leakage, always use the 2inch
spacer cone with the probe. Hold the probe
perpendicular to the cabinet door. Place the spacer
cone of the probe on the door and/or cabinet door
seam and move along the seam, the door viewing
window and the exhaust openings moving the
probe in a clockwise direction at a rate of 1 inch/sec. If the leakage testing of the cabinet door seam is
taken near a corner of the door, keep the probe perpendicular to the areas making sure that the probe end
at the base of the cone does not get closer than 5cm to any metal. If it gets closer than 5cm, erroneous
readings may result.
5) Measured leakage must be less than 4mW/cm2 , after repair or adjustment.
Maximum allowable leakage is 5mW/cm2 .
4mW/cm2 is used to allow for measurement and meter accuracy
5-11 Check for Microwave Leakage
1. Remove the outer panel.
2. Pour 275±15cc of 20±5°C(68±9°F) water in a beaker
which is graduated to 600cc, and place the beaker in
the center of the oven.
3. Start the oven at the highest power level.
4. Set survey meter dual ranges to 2,450MHz.
5. Using the survey meter and spacer cone as described
above, measure near the opening of magnetron, the
surface of the air guide and the surface of the wave
guide as shown in the following photo.( but avoid the
high voltage components.) The reading should be less than 4mW/cm2 .
5-12 Note on Measurement
1) Do not exceed the limited scale.
2) The test probe must be held on the grip of the handle, otherwise a false reading may result when the
operator's hand is between the handle and the probe.
3) When high leakage is suspected, do not move the probe horizontally along the oven surface; this may
cause damage to the probe.
4) Follow the recommendation of the manufacturer of the microwave energy survey meter.
5-13 Leakage Measuring Procedure
5-13-1 Record keeping and notification after measurement
1) After adjustment and repair of a radiation preventing device, make a repair record for the measured
values, and keep the data.
2) If the radiation leakage is more than 4mW/cm2 after determining that all parts are in good condition,
functioning properly and the identical parts are replaced as listed in this manual notify that fact to ;
CENTRAL SERVICE CENTER
5-13-2 At least once a year have the microwave energy survey meter checked for accuracy by its
manufacturer.
- 12 -
6. Troubleshooting
PRECAUTION
1.
2.
3.
4.
CHECK GROUNDING BEFORE CHECKING FOR TROUBLE.
BE CAREFUL OF THE HIGH VOLTAGE CIRCUIT.
DISCHARGE THE HIGH VOLTAGE CAPACITOR.
WHEN CHECKING THE CONTINUITY OF THE SWITCHES OR TRANSFORMER, DISCONNECT
ONE LEAD WIRE FROM THESE PARTS AND THEN CHECK CONTINUITY WITHOUT THE
POWER SOURCE ON. TO DO OTHERWISE MAY RESULT IN A FALSE READING OR DAMAGE
TO YOUR METER.
5. DO NOT TOUCH ANY PART OF THE CIRCUIT OR THE CONTROL CIRCUIT BOARD, SINCE
STATIC DISCHARGE MAY DAMAGE IT.
ALWAYS TOUCH GROUND WHILE WORKING ON IT TO DISCHARGE ANY STATIC CHARGE
BUILT UP.
6-1 Electrical Malfunction
SYMPTOM
CAUSE
CORRECTIONS
Oven is dead.
1. Open or loose lead wire harness
Fuse is OK.
2. Open thermal cutout (Magnetron)
No display and no operation at all. 3. Open low voltage transformer
4. Defective Ass'y PCB
Check fan motor when thermal
cutout is defective.
Check Ass'y PCB when L.V.T is
defective.
No display and no operation at all. 1. Shorted lead wire harness
2. Defective primary latch switch
Fuse is blown.
(NOTE 1)
3. Defective monitor switch (NOTE1)
4. Shorted H.V.Capacitor
5. Shorted H.V.Transformer (NOTE2)
Check adjustment of primary,
interlock monitor,
power relay, door sensing switch.
NOTE 1: All of these switches must be replaced at the same time.
(refer to adjustment instructions)
Check continuity of power relay contacts and if it has
continuity, replace power relay also.
NOTE 2: When H.V.Transformer is replaced, check diode and
magnetron also.
Oven does not accept
key input (Program)
1. Key input is not in-Sequence
2. Open or loose connection of
membrane key pad to Ass'y PCB
3. Shorted or open membrane panel
4. Defective Ass'y PCB
1. Off-alignment of latch switches
2. Open or loose connection of high
voltage circuit especially
magnetron filament circuit
NOTE: Large contact resistance will
bring lower magnetron
filament voltage and cause
Timer starts countdown but no
magnetron to lower output
microwave oscillation.
and/or intermittent oscillation.
(No heat while oven lamp and fan
3. Defective high voltage
motor turn on.)
components H.V.Transformer H.V.
Capacitor H.V.Diode, Magnetron
4. Open or loose wiring of power
relay
5. Defective primary latch switch
6. Defective power relay or Ass'y PCB
- 13 -
Refer to operation procedure.
Replace PCB main.
Adjust door and latch switches.
Check high voltage component
according to component test
procedure and replace if it is
defective.
Replace PCB main.
6-1 Electrical Malfunction(continued)
SYMPTOM
CAUSE
CORRECTIONS
Oven lamp and fan motor turn on
1. Misadjustment or loose wiring
of primary latch switch
2. Defective primary latch switch
Oven can program but timer
does not start.
1. Open or loose wiring of
secondary interlock switch
2. Off-alignment of primary
interlock
3. Defective secondary interlock S/W
Microwave output is low;.
Oven takes longer time to
cook food.
1. Decrease in power source
voltage.
2. Open or loose wiring of
magnetron filament circuit.
(Intermittent oscillation))
3. Aging of magnetron
Fan motor turns on when plugged in Loose wiring of door sensing switch
Adjust door and latch switches.
Adjust door and interlock
switches.
Consult electrician.
Check wire of door sensing
switch.
Oven does not operate and return to Defective Ass'y PCB
the plugged in mode.
Replace PCB main.
Loud buzzing noise can be heard.
1. Loose fan and fan motor
2. Loose screws on
H.V.Transformer
3. Shorted H.V.Diode
Tighten screws of fan motor.
Tighten screws of
H.V.Transformer.
Replace H.V.Diode.
Turntable motor does not rotate.
1. Open or loose wiring of
turntable motor.
2. Defective turntable motor.
Replace turntable motor.
1. Open or loose wiring of primary
interlock switch
2. Operation of thermal
cutout(Magnetron)
Adjust door and latch switches.
Oven stops operation during cooking
Sparks
Uneven cooking
1. Metallic ware or cooking dishes
touching on the oven wall.
2. Ceramic ware trimmed with
gold or silver powder also
causes sparks.
Uneven intensity of microwave due
to its characteristics.
Noise from the turntable motor when Noise may result from the motor.
it starts to operate.
- 14 -
Inform the customer.
Do not use any type of cookware
with
metallic trimming.
Wrap thinner parts of the food
with aluminum foil.
Use plastic wrap or cover with a
lid.
Stir once or twice while cooking
foods such as soup, cocoa, or
milk.
Replace turntable motor.
7. Exploded Views and Parts List
7-1 Exploded Views
MD11
MD04
MD06
MM01
MD08
MD02
MD05
MD17
MM52
MM67
MM59
MD09
MM07
MM03
MM62
MM65
MM61
MD07
MM68
MM69
MM132
MD10
MM63
MM21
MM72
MM172
MM55
MM60
MM34
MM57
MD01
MM17
MM06
MM71
MC01
MM10
MC13
MM16
MM13
MB03
MM08
MC07
MC03
MM22
MC02
MB01
MM171
MC06
MC04
MB05
MB02
MM14
MM28
MB04
MC05
MB08
MM30
MM29
MM18
MM19
MM20
MM31
MM64
MM27
- 15 -
MM09
7-2 Main Parts List
No.
Code No.
Description
Specification
Q'ty
Remark
MB01
DE96-00005C
ASSY BODY LATCH
2&2 ALL,D/SECSING VE,PP(FH44N),-,-,-
1
MB02
3405-001032
SWITCH-MICRO
125/250VAC,16A,200GF,SPDT
1
MON S/W
MB03
3405-001034
SWITCH-MICRO
125/250VAC,16A,200GF,SPST-NO
1
PRI S/W
MB04
DE66-90114A
LEVER-S/W
PP(FH44N),-,-,-,3.5g,NTR,3RD-W MW5592W,-
1
MB05
DE66-40001C
LATCH-BODY
-,-,-,-,-,NTR,39.2g
1
MB08
3405-001042
SWITCH-MICRO
DC 24V,0.3A,150gf,-
1
MM01
DE70-30002W
PANEL-OUTER
CK135,PCM,T0.6,-,-,-,P-WHT,-
1
MM03
DE39-00085A
WIRE HARNESS-A
MG1460WA/XAX,110V60HZ,-,-
1
MM06
DE31-00001G
MOTOR FAN-ASSY
SMF-789UA2,120V60HZ,2650RPM,MW1455WA,-
1
MM07
DE39-20146E
ASSY POWER CORD
MSP-36,-,-,-,-,-,SPT-2 3/16AWG,MB-53C,1.3MT,GRY
1
MM08
OM75P(31)ESS
ASSY-MAGNETRON:OM75P
MM09
DE71-60458A
COVER-AIR
3RD-1.0/1.3 MW5896W,PP(TB53),78g,-,-,-,WHT,-
1
MM10
4713-001012
LAMP-INCANDESCENT
130V,-,40W,ORG,B/L,-,25X71
1
MM13
DE66-90113A
LEVER-DOOR
PP(TB53-GH41),T2.5,-,-,12g,NTR,3RD-W,-
1
MM14
DE26-00061B
TRANS-H.V
SHV-U11KA_R,120V,60HZ,2300V/3.65,-,-,V TYPE,-
1
MM16
DE71-60461A
COVER-CEILING
3RD-1.0,MICA,T0.3,W114.2,L117.5,-,-,-
1
MM17
DE47-20009A
THERMOSTAT
PW2N-520PB,160/60,250V/7.5A,H,
1
MM171
DE47-20002A
THERMOSTAT
NT-101NA(8*V)140-130,250V7.5A,
1
MM172
DE47-00002B
THERMOSTAT
PW2N,-,-,100,110,-,-,-,187H,30.0
1
MM18
DE74-20002C
TRAY-COOKING
GLASS,T6,-,-
1
MM19
DE92-90189V
ASSY-GUIDE ROLLER
3RD-1.0 CMO,PI15.5,XAREC,CERAMIC-ENAMEL,-,-
1
MM20
DE67-00121A
COUPLER
PPS,-,-,BROWN,MW1455WA,T4.3*23.1
1
MM21
DE39-40409A
WIRE HARNESS-E
230V50HZ,M9G45,CTW,-,-,-
1
MM22
DE31-10154A
MOTOR-SYNCHRONOUS
M2HJ49ZR02,ST-16,50/60HZ,-
1
MM27
DE61-40066A
FOOT
-,PP,-,BLK,-,-,-
2
MM28
DE80-10002A
BASE-PLATE
-,SGCC,T(0.8),W(404),L(633),MW6574W,-
1
MM29
2501-001016
C-OIL
950nF,2.1KV,BK,35x54x80,20mm
1
MM30
DE61-50106A
BRACKET-HVC
-,SECC,T0.8,W31,L125.8,-,-
1
MM31
DE59-40001A
DIODE-H.V
HVR-1X-32B-12,-,-,-,-,-
1
MM34
DE47-40025A
HOLDER-FUSE
KFSN-L-16,15A,NYLON#66,5G,-,-,
1
MM52
DE63-90035I
CUSHION-RUBBER
-,DFA20,T1.5,W190,L100,-,-
1
MM55
3601-001198
FUSE-CARTRIDGE
250V,20A,SLOW-BLOW,CERAMIC,6.35x31.3mm
1
MM57
DE61-50027B
BRACKET-HEATER
-,SECC,T1.0,W51,L55,CE945GF,-
1
MM59
DE71-00154A
COVER-BACK
MG1430WA,SECC,T0.5,-,-,-,-,-,1.4-GRILL
1
MM60
DE63-20017A
GASKET-HEATER
-,BRASS,T1.5,OD30.5,ID22.5,-,-,-
1
MM61
DE47-70031D
HEATER-GRILL
SHG-6566U1,-,-,1300W,120V,-,-,-,-,FNG
1
MM62
DE61-70060A
SPRING-PLATE
-,SK-5,T0.5,T0.5,-,-,-,-,-,-,-
1
MM63
DE61-30006A
SUPPORT-HEATER
-,ALUMINA,5G,2ND-W/P,-,-,-
1
MM64
DE74-70038B
RACK-WIRE
MSWR10,PI3,D268,H140,MB6774W,-
1
MM65
DE72-60005C
GUIDE-AIR
-,SECC,T0.5,W210,L225,-,CE245G
1
MM67
DE61-00068B
BRACKET-UPPER
MG1430WA,SECC,T0.5,DEEP-DRAW,-,-,1.4-GRILL
1
MM68
DE60-40009B
WASHER-TEFLON
SLOT,ID22.2,OD28,T1.2,TEFLON,-
1
MM69
DE61-50021A
BRACKET-FLANGE
-,SECC1,T0.8,32,32,-,-
1
MM71
DE61-50490A
BRACKET-TCO
-,SECC1,T0.6,34,58,-,-
1
MM72
DE61-50025A
BRACKET-EARTH
-,BSS2-A,T1.0,CE745G,-,-,-
1
DOOR S/W
1
- 16 -
CV/AIR
GRILL
7-3 Control and Door Parts List
No.
Code No.
Description
Specification
Q'ty
MC01
-
ASSY CONTROL-BOX
120V60HZ,MG1460WA/XAX,WHITE,GRILL
1
MC02
DE34-00090L
SWITCH MEMBRANE
MG1460WA/XAX,-,-,PET,-,120V60HZ,S2,WHITE
1
MC03
DE72-70208C
CONTROL-PANEL
M1D33/CE2D33,ABS(HR0370U),P/WHT(W9501),-
1
MC04
DE61-70026A
SPRING-BUTTON
D17,CS,SWP,SWP,PI0.7,PI0.7,PI0.7,-,D17,-,L25.8
1
MC05
DE66-20281A
BUTTON-PUSH
3RD-W B DESIGN,-,T2x37x86,-,-,15g
1
MC06
DE67-40175A
WINDOW-DISPLAY
5G,SAN,-,-,-,-,SMG,-
1
MC07
RA-N2LED1-09
ASSY PCB PARTS:MB569
MC13
DE94-00015C
ASSY CONTROL-PANEL
-,CE2D33,P/WHT(W9501),S2-GRILL,-,-,-
1
MD01
DE94-00018Z
ASSY DOOR
MG1460WA/XAX,WHITE,S2-GRILL
1
MD02
DE64-40325A
DOOR-A
MWD49BW,ABS,-,-,-,-,WHT,-
1
MD03
DE67-00002B
SCREEN-DOOR
ACRYL,T1.5,W173.6,L373.5,CLEAR,MW7896W01,-
1
MD04
DE94-00019K
ASSY DOOR-E
MW7694W,BLK-COATING,3RD-1.3
1
MD05
DE01-00113B
FILM-DOOR
MD06
DE64-40010B
DOOR-C
M245,PP(TB53),1.2CU.FT,-,-,-,BLK,-
1
MD07
DE61-70128A
SPRING-KEY
BLUING,HSW3,PI0.6,PI0.6,D5,D5,D5,-,BLUING,-,-
1
MD08
DE61-80002A
HINGE-UPPER
WHT,SHV-745CC1,SSEC,T2.3,26,77,ZPC3,-,-
1
MD09
DE61-80003A
HINGE-LOWER
WHT,TN-5630T,SSEC,T2.3,26,77,ZPC3,-,-
1
MD10
DE64-40006F
DOOR-KEY
POM(F20-02),-,-,12G,BLK,MW7897G,NO-TALK
1
MD12
DE64-40324D
DOOR-SUB
MG1340BA/XAP,ABS,-,-,-,-,-,-
1
1
1
S.N.A : SERVICE NOT AVAILABLE
- 17 -
Remark
S.N.A
7-4 Standard Parts List
Code No.
Description
Specification
Q'ty
Remark
DE60-10012A
SCREW-TAP TITE
-,SWR10,M4,L10,TH,+,-,3,ZPC2,-
1
CONTROL
DE60-10012A
SCREW-TAP TITE
-,SWR10,M4,L10,TH,+,-,3,ZPC2,-
1
EARTH
DE60-10024A
SCREW-PH
-,ZPC3,L8,MSWR10,PH,+,-,M4,-,-
2
DE60-10053A
SCREW-TAP PH
-,-,FEFZY,-,PH,M4,-,L10,-,-
1
FUSE-HOLDER
DE60-10070A
SCREW-TAP TH
-,-,FEFZY,2-SLOT,TH,M4,-,L12,-,-
5
B-PLTE
DE60-10070A
SCREW-TAP TH
-,-,FEFZY,2-SLOT,TH,M4,-,L12,-,-
2
CN-BOX
DE60-10070A
SCREW-TAP TH
-,-,FEFZY,2-SLOT,TH,M4,-,L12,-,-
1
CV/AIR
DE60-10070A
SCREW-TAP TH
-,-,FEFZY,2-SLOT,TH,M4,-,L12,-,-
1
MGT-B/TCO
DE60-10070A
SCREW-TAP TH
-,-,FEFZY,2-SLOT,TH,M4,-,L12,-,-
2
MO/FAN
DE60-10080B
SCREW-WASHER
-,2S,SWRCH18A,ZP2,PH,PI5,-,L10,-,-
4
MGT
DE60-10080B
SCREW-WASHER
-,2S,SWRCH18A,ZP2,PH,PI5,-,L10,-,-
4
TNS-HV
DE60-10082H
SCREW-A
-,-,-,-,2S-4X12,TOOTHED,-,-,-,-
2
BD-LAT
DE60-10082H
SCREW-A
-,-,-,-,2S-4X12,TOOTHED,-,-,-,-
1
P-C-EA
DE60-10082H
SCREW-A
-,-,-,-,2S-4X12,TOOTHED,-,-,-,-
1
S-M-EA
DE60-10088A
SCREW-TAP PH
-,-,FEFZY,PLAIN,PH,M3,-,L8,-,-
1
MGT-TCO
DE60-10098A
SCREW-ASSY TAP TITE
-,GLD,SWRCH18A,ZPC2,PH,TC,-,M4X8,WT,-
2
M/DRIV
DE60-10122A
SCREW-TAP TH
-,-,FE,FN,TAP,TH,-,2-4X8,-,-
2
BKT-HEATER
DE60-10122A
SCREW-TAP TH
-,-,FE,FN,TAP,TH,-,2-4X8,-,-
3
COVER-CEILING
DE60-20063A
BOLT-FLANGE
M4,10,ZPC3,YEL,MSWR,-,-,-,-
4
DE60-10045A
SCREW-TAP PH
-,-,FEFZY,-,PH,M3,-,L6,-,-
1
DE60-10082J
SCREW-TAPPING
-,WS,ZPC,YEL,TH,2S-4X8,-,MSWR3,-,-
1
DE60-10012A
SCREW-TAP TITE
-,SWR10,M4,L10,TH,+,-,3,ZPC2,-
1
DE60-10045A
SCREW-TAP PH
-,-,FEFZY,-,PH,M3,-,L6,-,-
1
DE60-10088A
SCREW-TAP PH
-,-,FEFZY,PLAIN,PH,M3,-,L8,-,-
1
- 18 -
B/HVC
TCO
8. P.C.B Diagrams
8-1 P.C.B Diagrams
- 19 -
8-2 P.C.B Parts List
Code No.
Description
Specification
Q'ty
Remark
3501-001155
RELAY-MINIATURE
24VDC,200MW,3000MA,1FORMA,10MS,10MS
1
RY01
3501-001188
RELAY-POWER
24V DC,0.53W,-,1FormA,9.3ms,10mS
1
RY02
3501-001209
RELAY-POWER
24V DC,0.53W,-,1FORMA,9.3MS,10MS
1
RY04
3708-001551
CONNECTOR-FPC/FC/PIC
14P,1.25mm,STRAIGHT,SN
1
CN04
DE07-00021M
LED DISPLAY
CSQ-4246G-12,NC2000-GRILL,-,40SEG,5DIGIT,-
1
LED1
DE09-00054A
IC MICOM
TPM87CH47U,OTP-16K,QFP,-,44PIN,-
1
IC01
DE26-00037A
TRANS-L.V
SLV-4290U,120V,60Hz,AC17V/7V,-,35*10,PIN,-
1
LVT1
DE30-20016A
BUZZER
CBE2220BA,STICK,-,-,-,-,-,-,-
1
BUZ1
DE92-00696A
ASSY PCB AUTO
120V60HZ,LED,RA-N2LED1-09,MG850WA
1
0401-001083
DIODE-SWITCHING
MM4148,100V,150MA,LL-34,TP
15
D08~12,14~23
0402-001103
DIODE-RECTIFIER
1T4,400V,1A,TS-1,TP
7
D01~07
0403-001288
DIODE-ZENER
ZMM55C5V1,4.8-5.4V,500MW,LL-34,TP
1
ZD01
0501-000465
TR-SMALL SIGNAL
MMBT3904,NPN,350MW,SOT-23,TP,30-300
1
TR01
0504-001008
TR-DIGITAL
RN2427,PNP,200MW,2.2K/10K,SOT-23,TP
5
TR09~13
0504-001080
TR-DIGITAL
KRC246S,NPN,200mW,2.2K/10K,SOT-23,TP
4
TR02,04,05,08
1202-000141
IC-VOLTAGE COMP.
7033,SOT-89,3P,-,SINGLE,0V,-,P
1
IC03
1203-001037
IC-VOLTAGE REGULATOR
78L05,SOT-89,3P,185MIL,PLASTIC
1
IC02
1405-000001
VARISTOR
470V,1250A,14x7.5mm,TP
1
ZNR1
2007-000033
R-CHIP
0OHM,5%,1/8W,DA,TP,3216
4
J11,12,13,16
2007-000282
R-CHIP
100KOHM,5%,1/10W,DA,TP,2012
2
R27,28
2007-000300
R-CHIP
10KOHM,5%,1/10W,DA,TP,2012
3
R07,08,09
2007-000346
R-CHIP
120OHM,5%,1/8W,DA,TP,3216
8
R19~26
2007-000468
R-CHIP
1KOHM,5%,1/10W,DA,TP,2012
9
R01,03~05,10,13
2007-000671
R-CHIP
2KOHM,5%,1/10W,DA,TP,2012
1
R02
2007-000931
R-CHIP
470OHM,5%,1/10W,DA,TP,2012
1
R06
2007-000941
R-CHIP
47KOHM,5%,1/10W,DA,TP,2012
5
R14~18
2203-000444
C-CERAMIC,CHIP
1nF,10%,50V,X7R,TP,2012,-
6
C13~17,20
2203-001608
C-CERAMIC,CHIP
22nF,+80-20%,50V,Y5V,TP,2012
4
C09~12
2401-000151
C-AL
1000uF,20%,25V,GP,TP,10x20,5
1
C02
2401-000244
C-AL
100uF,20%,10V,GP,TP,6.3x7,5
1
C03
2401-000911
C-AL
22uF,20%,16V,GP,TP,5x7,5
2
C04,06
2401-002075
C-AL
4.7uF,20%,50V,GP,TP,5x11,5
1
C05
2401-002598
C-AL
220uF,20%,50V,GP,TP,10x16,5
1
C01
2802-000188
RESONATOR-CERAMIC
8MHz,0.5%,TP,10.0x5.0x8.0mm
1
XTL1
3711-000881
CONNECTOR-HEADER
BOX,3P,1R,2.5mm,STRAIGHT,SN
1
CN03
3711-004143
CONNECTOR-HEADER
BOX,2P/3P,1R,5mm/2.5mm,STRAIGH
1
CN02
DE39-60001A
WIRE-SO COPPER
PI0.6,SN,T,52MM,TAPING_WIRE,-,
10
J01~10
DE41-00178A
PCB-MAIN
RA-N2LED1-**,FR-1,1,T1.6*W247*L197,4ARRAY,-
1
DE60-60012A
PIN-EYELET
ID2.1,OD2.5,L3.0,SN,BSP,T0.25,
2
- 20 -
9. Schematic Diagrams
9-1 Schematic Diagrams
WARNING
POWER MUST BE DISCONNECTED
BEFORE SERVICING THIS APPLIANCE
CAVITY
TCO
L
FAN
MOTOR
FM
MAIN RELAY
L.V.TRANS
120V
DM
21V
0V
COM
H. V. CAPACITOR
NC
NO
GRILL
RELAY
VARISTOR
120V
130V
40W
POWER CORD
AC 120V/60Hz
HEATER
H. V. TRANSFORMER
MONITOR
SWITCH
LAMP
GRILL
TCO
PRIMARY S/W
D/MOTOR
FUSE
250V20A
FF
0V
A
MAGNETRON
MGT
TCO
POWER RELAY
(SECONDARY INTERLOCK)
1. INPUT : 120V 60HZ
2. DOOR : OPEN
3. LAMP : ON
4.
: P.C.B PATTERN
5.
: P.C.B IN/OUT POINT
NOTE: CIRCUIT SHOWN WITH DOOR IS OPENED POSITION.
NOTE: FOR SERVICE REPLACEMENT USE 16 GA 105°C
THERMOPLASTIC COVERED WIRE EXCEPT
FOR HIGH VOLTAGE LEADS OR AS NOTED ON SPECIAL LEADS.
PNK
MAGNETRON
BLK
HIGH VOLTAGE
DIODE
BLK
TO CHASSIS
BLK
PRIMARY SWITCH
TOP
FA
ORG
WHT
F
R
BLK
ORG
HIGH VOLTAGE CAPACITOR
RED
WHT
ORG
RED
BLK
DOOR SENSING SWITCH
BOTTOM
MONITOR SWITCH
CENTER
BLK
HIGH VOLTAGE
TRANSFORMER
WHT
WHT
WHT
WHT
POWER RELAY
- 21 -
SYMBOL
COLOR
ORG
WHT
BLK
BLU
RED
YEL
ORANGE
WHITE
BLACK
BLUE
RED
YELLOW
ELECTRONICS
©Samsung Electronics Co., Ltd. November 2001
Printed in Korea
Code No. : DE68-02416A