MICROWAVE OVEN
MW5480W / MW5481G
MW5380W / MW5381G
SERVICE
Manual
CONTENTS
MICROWAVE OVEN
1. Precaution
2. Specifications
3. Operating Instructions
4. Disassembly and Reassembly
5. Alignment and Adjustments
One Minute +
Popcorn
Diet Cook
Frozen
Dinner
Potato
Fresh
Vegetable
Frozen
Breakfast
Auto
Defrost
Auto
Reheat
1
4
7
Power Level
2
5
8
0
3
6. Troubleshooting
6
9
More/Less
Clock
Auto Start
Hold
Timer
Pause
Cancel
Start
7. Exploded Views and Parts List
8. PCB Diagrams
9. Schematic Diagrams
SEA
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. Microwave emission check should be
performed to prior to servicing if the oven is
operative.
2. 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 immediatly.
3. Notify the Central Service Center if the
microwave leakage exceeds 5 mW/cm2
4. Check all grounds.
5. 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.
6. When reinstalling the chassis and its
assemblies, be sure to restore all protective
devices, including: nonmetallic control
knobs and compartment covers.
7. 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.
8. Inform the manufacturer of any oven found
to have emmission 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.
SAMSUNG ELECTRONICS AMERICA, INC.
HEADQUARTER OFFICE
105 CHALLENGER ROAD
RIDGEFIELD PARK N.J.07660-0511
9. Service technicians should remove their
watches while repairing an MWO.
11. If the fuse is blown by the Interlock Monitor
Switch: Replace all of the following at the
same time: Primary and secondary switches,
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.
12. 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.10.Always unplug
the unit's AC power cord from the AC
power source before attempting to
remove or reinstall any component or
assembly.
13. 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.
14. 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.
15. 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.
10. 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.
Samsung Electronics
1-1
Pretaution
1-2 Special Servicing Precautions (Continued)
16. When checking the continuity of the
switches or transformer, always make sure
that the power is OFF, and one of the lead
wires is disconnected.
17. Components that are critical for safety are
indicated in the circuit diagram by
shading,
or
.
18. 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
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 the oven chassis. (Use a
screwdriver.)
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.
Fig. 1-1. Discharging the High Voltage Capacitor
1-2
Samsung Electronics
2. Specifications
2-1 Table of Specifications
MODEL
ITEM
MW5480W/MW5481G/MW5380W/MW5381G
TIMER
99 MINUTES 99 SECONDS
POWER SOURCE
120V/60HZ, AC
POWER CONSUMPTION
MICROWAVE : 1,300W
OUTPUT POWER
FROM 90W TO 900W (10 LEVEL POWER)
(IEC-705 TEST PROCEDURE)
OPERATING FREQUENCY
2,450MHz
MAGNETRON
OM75PH(31)ESS
COOLING METHOD
COOLING FAN MOTOR
OUTSIDE DIMENSIONS
20 (W) x 11 (H) x 14 (D)
NET WEIGHT
33.1 lbs.
SHIPPING WEIGHT
37.5 lbs
11/32
11/32
5/8
2-2 Comparison Chart
MODEL
Samsung Electronics
FEATURE
MW5480W/MW5481G/MW5380W/MW5381G
MORE/LESS
AUTO REHEAT
AUTO DEFROST
TIME COOK
POWER LEVEL
INSTANT COOK
MEMORY
BOOST
CHILD LOCK
CLOCK
GRILL
COMBI
Ο
Ο
Ο
Ο
Ο
Ο
Ο
−
Ο
Ο
−
−
2-1
3. Operating Instructions
3-1 Control Panel
MW5480W / MW5481G
MW5380W / MW5381G
One Minute +
Popcorn
2
1
Potato
Fresh
Vegetable
Frozen
Breakfast
Auto
Defrost
Auto
Reheat
4
7
1. One Minute + Button
2. Auto Defrost Button
3. Power Level Selection Button
4. Clock/Auto Start Button
5. Hold/Timer Button
6. More/Less Button
7. Pause Canel Button
8. Start Button
9. Instant Cook Button
10. Auto Reheat Button
11.Number Key Button
Diet Cook
Frozen
Dinner
1
One Minute +
2
5
8
0
Popcorn
Diet Cook
Fresh
Vegetable
Frozen
Dinner
Auto
Defrost
Auto
Reheat
9
2
0
1
2
3
4
5
6
7
8
9
Power Level
0
More/Less
6
Clock
Auto Start
Hold
Timer
5
Pause
Cancel
Start
8
3
6
9
A
More/Less
6
4
5
7
8
3
Power Level
4
Clock
Auto Start
Hold
Timer
7
Pause
Cancel
Start
0
3
3-2 Features & External Views
Door
Ventilation Slot
Light
Safety Interlock Holes
One Minute +
Popcorn
Potato
Fresh
Vegetable
Frozen
Breakfast
Auto
Defrost
Auto
Reheat
1
4
7
Door Latches
Diet Cook
Frozen
Dinner
Power Level
2
5
8
0
Control Panel
3
6
9
More/Less
Clock
Auto Start
Hold
Timer
Pause
Cancel
Start
Open Door Push Button
Glass Plate
Guide Roller
One Minute +
Popcorn
Potato
Fresh
Vegetable
Frozen
Breakfast
Auto
Defrost
Auto
Reheat
1
4
7
Power Level
2
5
8
0
297.3mm
Diet Cook
Frozen
Dinner
3
6
9
More/Less
Clock
Auto Start
Hold
Timer
Pause
Cancel
Start
216.4mm
369mm
517mm
Samsung Electronics
317.4mm
3-1
4. Disassembly and Reassembly
4-1 Replacement of Magnetron, Motor Assembly and Lamp
Remove the magnetron including the shield case,
permanent magnet, choke coils and 500pF
capacitors (all of which are contained in one
assembly).
1. Disconnect all lead wires from the magnetron
and lamp.
2. Remove the air cover.
3. Remove screws securing the magnetron to the
wave guide.
4. Take out the magnetron very carefully.
5. Remove screws from the back panel.
6. Take out the fan motor.
7. Remove the oven lamp by pulling out from hole
of air cover.
8. NOTE1: When removing the magnetron, make
sure that its antenna does not hit any
adjacent parts, or it may be damaged.
9. 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.
Cover Air
Thermo S/W
Lamp
Fan Motor
Screw
Magnetron
H. V. Trans
H. V. Capacitor
4-2 Replacement of High Voltage Transformer
1. Discharge the high voltage capacitor.
2. Disconnect all the leads.
3. Remove the mounting bolts.
4. Reconnect the leads correctly and firmly.
Bolts
Samsung Electronics
H. V. Trans
4-1
Disassembly and Reassembly
4-3 Replacement of Door Assembly
4-3-1 Removal of Door Assembly
Remove screws securing the upper hinge and
lower hinge. Then remove the door assembly.
Upper Hinge
Screw
Lower Hinge
Screw
4-3-2 Removal of Door "C"
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.
Door "C"
Door "A"
4-3-3 Removal of 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.
Door "E"
1. Insertion depth of the thin metal plate should be
0.5mm or less.
4-2
Samsung Electronics
Disassembly and Reassembly
4-3-4 Removal of Key Door & Spring
1. Remove pin hinge from Door "E"
Detach spring from Door "E" and key door.
Door "E"
2. 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.
3. 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.
Key Door
Spring
4. 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.
5. Do the microwave leakage test.
4-4 Replacement of Fuse
1. Disconnect the oven from the power source.
2. Remove the 15A fuse in the fuse holder.
3. When replacing the 15A fuse, be sure to use an
exact replacement part. If new 15A fuse blows
out again after replacement, check the primary
interlock switch, door sensing switch and
interlock monitor switch.
4. 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 and the guide roller from
the cavity.
2. Turn the oven upside down to replace the drive motor.
Drive Motor
Screw
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.
Thermo
Switch
6. Remove the drive motor and the coupler.
7. When replacing the drive motor, be sure to
remount it in the correct position with the
coupler.
Drive Motor Cover
Base Plate
8. Connect all the leads to the drive motor.
9. Screw the drive motor cover to the base plate
with a screw driver.
Samsung Electronics
4-3
Disassembly and Reassembly
4-6 Replacement of Control Circuit Board
4-6-1 Removal of Control Box Assembly
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.
2. Remove screws securing the control circuit
board.
FPC Connector
Screw
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.
2. The membrane key board is attached to the
escutcheon base with doublefaced 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.
4-4
Window
Display
Membrane
Panel
Samsung Electronics
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
Secondary
Filament
Primary
Filament Terminals
SHV-557UC1
90Ω ± 10%
Shows Continuity
0.40Ω ± 10%
(Room temperature = 20ûC)
Secondary
Terminal
Primary
Terminals
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.
Terminals
1~2(Input)
4~5(Output17V)
7~8(Output2.7V)
Resistance
DN-5574W
CE-5574W
312.3Ω
11.22Ω
2.213Ω
286.5Ω
9.245Ω
1.735Ω
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
Gasket Plate
Cooling Fins
Samsung Electronics
5-1
Alignment and Adjustments
5-4 High Voltage Capacitor
1. Check continuity of the capacitor with the meter set at the highest resistance scale.
2. Once the capacitor is charged, a normal capacitor shows continuity for a short time, and then indicates 9MΩ.
3. A shorted capacitor will show continuous continuity.
4. An open capacitor will show constant 9MΩ.
5. 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 interlock and door sensing 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.
Primary Interlock Switch
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.
4. Reconnect to Monitor switch and check the
continuity of the monitor circuit and all latch
switches again by following the components test
procedures.
5. Confirm that the gap between the switch
housing and the switch actuator is no more than
0.5mm when door is closed.
5-2
Interlock Monitor
Switch
Lever Door
Body Latch
Primary switch
Monitor switch (COM-NC)
Door Sensing S/W
Door Sensing
Switch
Door Open
Door Closed
∞
0
∞
0
∞
0
Samsung Electronics
Alignment and Adjustments
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 the water temperature ("T1", 10±1ûC) in the glass vessel.
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 48 seconds exactly. (1 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)
46.5
46.5: Heating Time (sec)
4.187 : Coefficient for Water
1000 : Water (cc)
∆T : Temperature Rise (T2-T1)
Mc : Cylindrical borosilicate glass weight
To : Room temperature.
7. Normal temperature rise for this model is 9ûC to 11ûC 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 80
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 2 minutes, 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(%)
Beaker
D
The result should exceed 65%.
D/4
D/4
D/4
D/4
Samsung Electronics
Cooking Tray
5-3
Alignment and Adjustments
5-10 Procedure for Measurement of Microwave Energy Leakage
1) Pour 275±15cc of 20±5ûC ( 68±9ûF) 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 2 inch
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 2 inches to any
metal. If it gets closer than 2 inches, erroneous readings may result.
5) Measured leakage must be less than 5mW/cm2, after repair or adjustment.
One Minute +
Popcorn
Diet Cook
Frozen
Dinner
Potato
Fresh
Vegetable
Frozen
Breakfast
Auto
Defrost
Auto
Reheat
1
4
7
Power Level
2
5
8
0
3
6
9
More/Less
Clock
Auto Start
Hold
Timer
Pause
Cancel
Start
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±5ûC(68±9ûF) 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 arnear 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 neading
should be less than 5mW/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
5-9-1 Record keeping and notification after measurement
1) After adjustment and repair of a radiarion preventing device, make a repair record for the measured
values, and keep the data.
2) If the radiation leakage is more than 5 mW/cm2 after determining that all parts are in good condition,
functioning properly and the identical parts are replaced as listed in this manual notift that fact to ;
SAMSUNG ELECTRONICS AMERICA, INC.
HEADQUARTER OFFICE
105 CHALLENGER ROAD
RIDGEFIELD PARK N.J.07660-0511
5-9-2 At least once a year have the microwave energy survey meter checked for accuracy by its
manufacturer.
5-4
Samsung Electronics
6. Troubleshooting
PRECAUTION
1. CHECK GROUNDING BEFORE CHECKING FOR TROUBLE.
2. BE CAREFUL OF THE HIGH VOLTAGE CIRCUIT.
3. DISCHARGE THE HIGH VOLTAGE CAPACITOR.
4. 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.
No display and no operation at all. 1. Shorted lead wire harness
Fuse is blown.
2. Defective primary latch switch (NOTE 1)
3. Defective monitor switch (NOTE1)
4. Shorted HVCapacitor
5. Shorted HVTransformer (NOTE2)
Check adjustment of primary, interlock monitor,
door sensing switch.
Check Ass'y PCB when LVT is defective.
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 HVTransformer is replaced, check diode and magnetron also.
Oven does not accept
key input (Program)
Timer starts countdown but no
microwave oscillation.
(No heat while oven lamp and
fan motor turn on.)
Samsung Electronics
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
Refer to operation procedure.
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 magnetron to lower output and/or
intermittent oscillation.
3. Defective high voltage 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
Adjust door and latch switches.
Replace PCB main.
Check high voltage component according to
component test procedure and replace if it is
defective.
Replace PCB main.
6-1
Troubleshooting
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
Adjust door and latch switches.
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
Adjust door and interlock switches.
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
Consult electrician.
Fan motor turns on when plugged in
Loose wiring of door sensing switch
Check wire of door sensing switch.
Oven does not operate and return
to the plugged in mode.
Defective Ass'y PCB
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.
Check the wire of turntable motor.
Replace turntable motor.
Oven stops operation during cooking
1. Open or loose wiring of primary
interlock switch
2. Operation of thermal cutout(Magnetron)
Adjust door and latch switches.
Sparks
1. Metallic ware or cooking dishes
touching on the oven wall.
2. Ceramic ware trimmed with gold or
silver powder also causes sparks.
Inform the customer.
Do not use any type of cookware with
metallic trimming.
Uneven cooking
Uneven intensity of microwave due to
its characteristics.
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.
Noise from the turntable motor
when it starts to operate.
Noise may result from the motor.
Replace turntable motor.
6-2
Samsung Electronics
7. Exploded Views and Parts List
7-1 Exploded Views
D5
D4
1
D7
D1
M27
M29
D6
M2
M3
D2
M26
M4
D3
M5
M31
M24
M6
M25
M30
M8
M10
M22
M11
M28
M7
B1
M21
B2
B3
M9
M12
M23
M20
B4
M14
M13
C5
C6
C4
C7
C2
C3
C1
M15
M19
M16
M17
M18
Samsung Electronics
7-1
Exploded Views and Parts List
7-2 Main Parts List
Ref. No.
Parts No.
Description/Specification
Q'ty
M 1
DE70-30001A
PANEL-OUTER;SECC T0.6 360 1128 EPOXY-COA
1
MW5480W
M 1
DE70-30001B
PANEL-OUTER;SECC T0.6 360 1128 PRESS
1
MW5380W
M 1
DE70-30001C
PANEL-OUTER;V/STEEL T0.7 360 1128 STONE GRAY
1
MW5481G/MW5381G
M 2
DE32-10026A
FUSE;NORMAL BLO 3AB-314015
1
M 3
3602-001002
FUSE-HOLDER;125V/250V,15A/7.5A,50mohm
1
M 4
DE31-10156B
MOTOR-FAN;SMF-557UC 120/60 2600 MW5574W
1
M 5
DE39-40505B
WIRE HARNESS-A;120V60HZ MW5574W
1
M 6
DE47-20009A
THERMOSTAT;CS-7SA(160/60)187Y 250V7.5A 1
1
M 7
DE03-30035A
MAGNETRON;OM75PH(31)ESS
1
M 8
4713-001012
LAMP-INCANDESCENT;130V,-,40W,ORG,B/L,-,2
1
M 9
DE71-60016A
COVER-AIR;PP 2 WHT M945/MB45
1
M 10
DE93-20001A
ASSY BODY LATCH;2ND-W1 M97G45/M9745
1
M 11
DE66-90013A
LEVER-DOOR;POM(F20-01) NTR MW5630T
1
M 12
DE26-10134A
TRANS-H.V;SHV-5574UC1 120V 2160V/3.35V
1
M 13
2501-001039
C-OIL;910nF,2100V,BK,35x54x75,20mm
1
M 14
DE61-50106A
BRACKET-HVC;SECC T0.8 W31 L125.8
1
M 15
DE59-40001A
DIODE-H.V;HVR-1X-32B-12
1
M 16
DE74-20015B
TRAY-COOKING;GLASS T6.0 PI318 1050G MW56
1
M 17
DE92-90189D
ASSY-GUIDE ROLLER;D19 STD
1
M 18
DE67-60026C
COUPLER;PTFE 12G WHT MB245
1
M 19
DE61-40017A
FOOT;PP(A353) BLK MW5630T
2
M 20
DE80-10001A
BASE-PLATE;SGCC T0.8 345 565
1
M 21
DE31-10154A
MOTOR-DRIVE;M2HJ49ZR02,ST-16 21V 5/6
1
M 22
DE71-60011A
COVER-MGT;PP T2.0 WHT M745
1
M 23
ASSY CONTROL-BOX;120V60HZ MW5480W /XAA WHT
1
MW5480W
M 23
ASSY CONTROL-BOX;120V60HZ MW5481G GRAY(NEWG
1
MW5481G
M 23
ASSY CONTROL-BOX;120V60HZ MW5380W WHT8
1
MW5380W
M 23
ASSY CONTROL-BOX;120V60HZ MW5381G GRAY(NEWG
1
MW5381G
M 24
ASSY DOOR;TOUCH WHT MW5470W 800W
1
MW5480W/MW5380W
M 24
ASSY DOOR;TOUCH GRAY MW5471G
1
MW5481G/MW5381G
M 25
DE61-80003A
HINGE-LOWER;SCP1 T2.3 26 77 ZPC3 WHT CHR
1
M 26
DE61-80002A
HINGE-UPPER;SCP1 T2.3 26 77 ZPC3 WHT CHR
1
M 27
DE39-20049C
ASSY POWER CORD;KKP-30/SPT-2#3/16 125V13
1
M 28
DE47-20173A
THERMOSTAT;PW-2N(90/60)30 187Y 250V7.5A
1
M 29
DE63-90035G
CUSHION-RUBBER;DFA20 T2 W190 L100 BLK
1
M 30
DE61-50490A
BRACKET-TCO;SECC1 T0.6 34 58
1
M 31
DE91-70101C
ASSY-THERMOSTAT;MW5574W 160/60 187-HORIZ
1
: Option Parts
7-2
: Warning
Remarks
:Electrostatically Sensitive Devices
Samsung Electronics
Exploded Views and Parts List
7-3 Door Parts List
Ref. No.
D
D
D
D
D
D
D
D
Parts No.
Description/Specification
Q'ty
Remarks
MW5480W/MW5380W
MW5481G/MW5381G
1
1
2
3
4
4
5
6
DE64-40241A
DE64-40241B
DE64-40006B
DE61-70032A
DE67-20157A
DE67-20157B
DE92-50127I
DE64-40012B
DOOR-A;ABS WHT M841
DOOR-A;ABS WHT (HRO370) GRY MW5471G
DOOR-KEY;POM(TC3005) T2 12GR WHT MW557
SPRING-KEY;ES HSWR PI0.6 D5.4 L25 MW8640
SCREEN-DOOR;PC T0.5 181.5 331.5 PURE-WHT
SCREEN-DOOR;PC T0.5 181.5 331.5 GRY MW5471G
ASSY DOOR-E;COATING WHITE T0.8
DOOR-C;PP(TB53) T2 MW5574W WHT
1
1
1
1
1
1
1
1
D 7
DE01-00002B
FILM-DOOR;PC T0.15 275 175 MW5574W
1
MW5480W/5380W
MW5481G/5381G
7-4 Control Parts List
Ref. No.
Parts No.
Description/Specification
Q'ty
Remarks
C 1
C 1
C 2
DE66-20010A
DE66-20010B
DE61-70076A
BUTTON-PUSH;ABS WHT MW4370W
BUTTON-PUSH;ABS D-GRY MW4371G
SPRING-BUTTON;HSWR PI0.6
1
1
1
MW5480W/MW5380W
MW5481G/MW5381G
C 3
DE34-10217P
SWITCH-MEMBRANE;PET 120V60HZ MW5480W 91.5
1
MW5480W
C 3
DE34-10217R
SWITCH-MEMBRANE;PET 120V 0.5A 174.5X91.5 MW5
1
MW5380W
C 3
DE34-10217C
SWITCH-MEMBRANE;PET 120V60HZ MW5471G 91.5
1
MW5481G
C 3
DE34-10217D
SWITCH-MEMBRANE;PET 120V60HZ MW5371G 91.5
1
MW5381G
C 4
DE72-70161A
CONTROL-PANEL;ABS(HR0370U) WHT M841
1
MW5480W/MW5380W
C 4
DE72-70161B
CONTROL-PANEL;ABS(HR0370U) WHT M841
1
MW5481G/MW5381G
C 5
DE67-40003A
WINDOW-DISPLAY;ACRYL T2.3 W36.8 L91.8 SM
1
C 6
DE91-10368A
ASSY P.C.B-MAIN;120V/60HZ NS V.F.D N/HEL
1
C7
DE93-30402A
ASSY CONTROL-PANEL;120V60HZ NEWGARD MW5470W
1
7-5 Body Latch Parts List
Ref. No.
Parts No.
B 1
DE66-40001A
LATCH-BODY;POM(F20-02) 40GR NTR
1
B 2
3405-000178
SWITCH-MICRO;250V,15A,200gf,SPST-NO
2
B 3
3405-000175
SWITCH-MICRO;250V,15A,200gf,SPST-NO
1
B 4
DE66-90001A
LEVER-SWITCH;P.O.M(F20-02) 2 6 NTR 2ND-W
1
Samsung Electronics
Description/Specification
Q'ty
Remarks
7-3
Exploded Views and Parts List
7-6 Standard Parts List
Parts No.
Description / Specification
Q'ty
Remarks
DE60-10082A
SCREW-A;M4 L12 2S TOOTHED
2
BASE
DE60-10088A
SCREW-TAP PH;PH M3 L8 FEFZY PLAIN
2
PCB
DE60-10082A
SCREW-A;M4 L12 2S TOOTHED
2
B-LATC
DE60-10082A
SCREW-A;M4 L12 2S TOOTHED
2
C-PANE
DE60-10082A
SCREW-A;M4 L12 2S TOOTHED
5
O-PANEL
DE60-10082A
SCREW-A;M4 L12 2S TOOTHED
1
P/EART
DE60-10080A
SCREW-WASHER;M5 L12 2S
4
HVT
DE60-10080A
SCREW-WASHER;M5 L12 2S
4
MGT
DE60-10033A
SCREW-TH;TH + M4 L10 MSWR10 FEFZY
2
HI-LOW
DE60-10082A
SCREW-A;M4 L12 2S TOOTHED
2
C-BLOW
DE60-10033A
SCREW-TH;TH + M4 L10 MSWR10 FEFZY
2
HI-UPP
DE60-10045A
SCREW-TAP PH;PH M3 L6 FEFZY
2
MGT-TC
DE60-10082A
SCREW-A;M4 L12 2S TOOTHED
1
MEM-PN
DE60-10098A
SCREW-ASSY TAPTITE;PH TC M4X8 SWRCH18A Z
1
CV-TCO
DE60-10098A
SCREW-ASSY TAPTITE;PH TC M4X8 SWRCH18A Z
2
M/GEAR
DE60-10113A
SCREW-TAP PH;2S-4X12 FE ZPC3
1
FUSE-H
DE60-10188A
SCREW-ASSY TAP;2S-4X8 MSW3ZPC YEL WS
Q1
B/HVC
7-4
Samsung Electronics
8. P.C.B Diagrams
8-1 P.C.B Diagrams
Samsung Electronics
8-1
P.C.B Diagrams
8-2 P.C.B Parts List
Parts No.
0401-001002
0402-000559
0501-000283
0504-001014
0504-001015
1405-000129
2001-000037
2001-000273
2001-000290
2001-000429
2001-000515
2001-000577
2001-000613
2001-000780
2001-000786
2001-000904
2011-000582
2202-000121
2202-000127
2202-000780
2401-000247
2401-000466
2401-000914
2401-001412
2802-000161
3501-001014
3501-001016
3708-000529
3711-000240
3711-000881
A4106-0154
DE07-10035A
DE09-30491A
DE13-20009A
DE26-20144A
DE30-20016A
DE39-60001A
DE60-60012A
DE61-90164A
8-2
Description / Specification
DIODE-SWITCHING;1N4148M,100V,200mA,500mW
DIODE-RECTIFIER;D4G,400V,1A,T-1
TR-SMALL SIGNAL;KSA539-Y,PNP,400mW,TO-92
TR-DIGITAL;KSR1005,NPN,300mW,4.7K-10K,TO
TR-DIGITAL;KSR2005,PNP,300mW,4.7K-10K,TO
VARISTOR;INR14D271K 270V,4500A 17X12MM,T
R-CARBON(S);330ohm,5%,1/2W,AA,TP,2.4x6.4
R-CARBON;100Kohm,5%,1/8W,AA,TP,1.8x3.2m
R-CARBON;10Kohm,5%,1/8W,AA,TP,1.8x3.2mm
R-CARBON;1Kohm,5%,1/8W,AA,TP,1.8x3.2mm
R-CARBON;220ohm,5%,1/8W,AA,TP,1.8x3.2mm
R-CARBON;2Kohm,5%,1/8W,AA,TP,1.8x3.2mm
R-CARBON;3.9Kohm,5%,1/8W,AA,TP,1.8x3.2m
R-CARBON;470ohm,5%,1/8W,AA,TP,1.8x3.2mm
R-CARBON;47Kohm,5%,1/8W,AA,TP,1.8x3.2mm
R-CARBON;620ohm,5%,1/8W,AA,TP,1.8x3.2mm
R-NETWORK;47Kohm,5%,1/8W,A,SIP,9P,TP
C-CERAMIC,MLC-AXIAL;UP050B101KBB 100PF,1
C-CERAMIC,MLC-AXIAL;TP050F103ZB 10NF,+80
C-CERAMIC,MLC-AXIAL;UP050F104Z 100NF,+80
C-AL;1SA1ANB107MAN 100UF,20%,10V,GP 6.3X
C-AL;CESSM1V100M0507 10UF,20%,35V,GP 5X7
C-AL;CESSL1C220M0511AA 22UF,20%,16V,GP 5
C-AL;1SG1VFB477MAN 470UF,20%,35V,GP 10X1
RESONATOR-CERAMIC;CST4.00MGW-TF01-3/CN 4
RELAY-POWER;OM1F-S-124LM 24V,21.8MA,17A
RELAY-MINIATURE;JV24-KT 24V,12.5MA,5A 1F
CONNECTOR-FPC/FC/PIC;FCZ254-14SL,BLK 14P
CONNECTOR-HEADER;1WALL,4P,1R,3.96mm,STRA
CONNECTOR-HEADER;SMW250-03,WHT BOX,3P,1R
DIODE-ZENER;TZP5.1B 5.1/5.7V 40MA T 1W
V.F.DISPLAY;SVM-07SS10 SEA
IC-MCU;MB89143AP-168 8K DIP 64PIN
IC;KA7533 DIP
TRANS-L.V;DN-5574W,CE-5574W 120V 60HZ AC
BUZZER;CBE2220BA STICK
WIRE-SO COPPER;PI0.6 SN T 52MM
PIN-EYELET;ID2.1 OD2.5 L3.0 SN BSP T0.25
HOLDER-DIGITRON;NYLON#66 T1.8 BLK MW4370
Q'ty
Remarks
16
3
1
5
4
1
2
2
5
4
1
1
8
2
20
1
1
1
1
4
1
1
1
2
1
1
1
1
1
1
3
1
1
1
1
1
25
8
1*
D05~20
D01,02,04
Q08
Q01,06,07,09,10
Q02~05
ZNR1
R03~04
R17,21
R07,10,14,15,19
R05,06,11,12
R09
R13
R16,18,20,26~30
R01,02
R31~50
R08
AR01
C09
C10
C05~07,11
C14
C08
C03
C01,02
X-TAL
RY02
RY01
CON05
CON01
CON04
ZD01~03
VFD1
IC01
IC02
LVT1
BUZ1
J01~25
Samsung Electronics
9. Schematic Diagrams
9-1 Schematic Diagrams
WARNING
POWER MUST BE DISCONNECTED
BEFORE SERVICING THIS APPLINACE
FUSE
BLK
CAVITY
TCO
PRIMARY S/W
BLK
H. V. TRANSFORMER
BLK
125V15A
BLK
N
YEL
120V
FM
21V
MONITOR
SWITCH
ORG
FAN
MOTOR
L
MAIN RELAY
VARISTOR
L
POWER CORD
AC 120V/60Hz
L.V.TRANS
BLK
D/MOTOR
LAMP
BLK
130V
40W
BLK
120V
COM
H. V. CAPACITOR
DM
NC
0V
NO
YEL
WHT
ORG
F
0V
FA
WHT
MAGNETRON
WHT
WHT
POWER RELAY
(SECONDARY INTERLOCK)
MGT
TCO
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.
1. INPUT : 120V 60HZ
2. DOOR : OPEN
3. LAMP : ON
4.
: P.C.B PATTERN
5.
: P.C.B IN/OUT POINT
MAGNETRON
BLK
HIGH VOLTAGE
DIODE
BLK
TO CHASSIS
BLK
PRIMARY SWITCH
TOP
FA
ORG
WHT
F
RED
BLK
ORG
HIGH VOLTAGE CAPACITOR
BLK
RED
WHT
ORG
RED
BLK
DOOR SENSING SWITCH
BOTTOM
MONITOR SWITCH
CENTER
BLK
HIGH VOLTAGE
TRANSFORMER
WHT
WHT
SYMBOL
COLOR
ORG
WHT
BLK
BLU
RED
ORANGE
WHITE
BLACK
BLUE
RED
WHT
POWER RELAY
Samsung Electronics
9-1