SAMSUNG MR4381GXAA Service Manual

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Page 1

MICROWAVE OVEN

MR4381G

SERVICE

Manual

MICROWAVE OVEN

CONTENTS

1. Precaution

2. Specifications

3. Operating Instructions

4. Disassembly and Reassembly

5. Alignment and Adjustments

6. Troubleshooting

7. Exploded Views and Parts List

8. PCB Diagrams

9. Schematic Diagrams

SEA

One Minute +

Popcorn

Frozen Dinner

Power Level

Auto Start Hold

Timer More

Less

123 456 7

Auto Defrost

Auto Reheat

Clock

Pause Cancel

Start

Page 2

Samsung Electronics

(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.

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.

PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO A VOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY

Page 3

1. Precaution

1-1 Safety precautions ( )

Samsung Electronics 1-1

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. 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).

2. Microwave emission check should be performed to prior to servicing if the oven is operative.

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 immediatly.

4. Notify the Central Service Center if the microwave leakage exceeds 5 mW/cm

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.

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.

9. 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

10. Service technicians should remove their watches while repairing an MWO.

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.

12. 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.

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.10.Always unplug the unit's AC power cord from the AC power source before attempting to remove or reinstall any component or assembly.

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.

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.

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.

Page 4

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. High Voltage Warning Do not attempt to measureany 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.

1-2

Pretaution

Samsung Electronics

1-2 Special Servicing Precautions (Continued)

1-3 Special High Voltage Precautions

Fig. 1-1. Discharging the High Voltage Capacitor

Page 5

2. Specifications

2-1 Table of Specifications

ITEM TIMER 99 MINUTES 99 SECONDS POWER SOURCE 120V/60HZ, AC POWER CONSUMPTION MICROWAVE : 1,150W OUTPUT POWER FROM70 TO 700W (10 LEVEL POWER)

OPERATING FREQUENCY 2,450MHz MAGNETRON OM75SH(31) COOLING METHOD COOLING FAN MOTOR OUTSIDE DIMENSIONS 191/4"(W) x 115/8"(H) x 139/16"(D) NET WEIGHT 30 LBS. SHIPPING WEIGHT 33 LBS.

MODEL MR4381G

(IEC-705 TEST PROCEDURE)

2-2 Comparison Chart

MODEL

FEATURE

MORE/LESS O

AUTO REHEAT O AUTO DEFROST O TIME COOK O POWER LEVEL O INSTANT COOK O MEMORY BOOST CHILD LOCK O CLOCK O GRILL COMBI -

MR4381G

Samsung Electronics 2-1

Page 6

One Minute +

Popcorn

Frozen Dinner

Power Level

Auto Start

Hold Timer

More Less

1 2 3 4 5 6

Auto Defrost

Auto Reheat

Clock

Pause Cancel

Start

One Minute + Button

Instant Cook Button

Auto Defrost Button

Auto Reheat Button

Number Key Button

Start Button

Clock / Auto Start Button

Hold / Timer Button

Power Level Button

More / Less Button

Pause / Cancel Button

3. Operating Instructions

3-1 Control Panel

Samsung Electronics 3-1

3-2 Features & External Views

Door

Duct Air

Ventilation Holes Light

Safety Interlock Holes

Control Panel

Open Door Push Button

Guide Roller

Glass Plate

Door Latches

One Minute +

Popcorn

Frozen Dinner

Power Level

Auto Start Hold

Timer More

Less

1 2 3 4 5 6 7

Auto Defrost

Auto Reheat

Clock

Pause Cancel

Start

489mm

357mm

295mm

200mm

344mm

One Minute +

Popcorn

Frozen Dinner

Power Level

Auto Start Hold

Timer More

Less

1 2 3 4 5 6 7

Auto Defrost

Auto Reheat

Clock

Pause Cancel

Start

Page 7

3-2

Samsung Electronics

3-3 Installation Instructions

Operating Instructions

CAUTION

THIS OVEN WAS MANUFACTURED FOR USE IN A RECREATIONAL VEHICLE ONLY. MAY BE BUILT INTO A CABINET STRUCTURE, BUT NOT FOR USE ADJACENT TO (WITHIN 2 FEET OF) ANY GAS OR ELECTRIC RANGE, COOKTOP, OR OVEN PLUG THE THREE-PRONG POWER CORD INTO A PROPERLY GROUNDED OUTLET, 120V, 60Hz

SCREW

(Trim to outcase)

SCREW

(Trim to outcase)

SCREW

(Trim to cabinet)

(Fig. 1) (Fig. 2)

DEPTH(13 )

1/4''

WIDTH (19 )

3/8''

HEIGTH

(11 )

7/8''

Page 8

4. Disassembly and Reassembly

4-1 Replacement of Magnetron, Motor Assembly and Lamp

Samsung Electronics 4-1

Remove the magnetron including the shield case, permanent magnet, choke coils and capacitors (all of which are contained in one assembly).

1. Disconnect all lead wires from the magnetron and lamp.

2. Remove the bracket mounting.

3. Remove the air cover.

4. Remove screws securing the magnetron to the wave guide.

5. Take out the magnetron very carefully.

6. Remove screws from the back panel.

7. Take out the fan motor.

8. Remove the oven lamp by pulling out from hole of air cover carefully.

NOTE1: When removing the magnetron, make

sure that its antenna does not hit any adjacent parts, or it may be damaged.

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.

1. Discharge the high voltage capacitor.

2. Disconnect all the leads.

3. Remove the mounting bolts.

4. Reconnect the leads correctly and firmly.

4-2 Replacement of High Voltage Transformer

Lamp

Cover Air

Magnetron

H. V. Trans

H. V. Capacitor

Screw

Thermo S/W

Fan Motor

H. V. Trans

Bolts

BKT-Mountain

Page 9

4-3 Replacement of Door Assembly

4-3-1 Removal of Door Assembly

4-2 Samsung Electronics

Remove screws securing the upper hinge and lower hinge. Then remove the door assembly.

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.

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.

4-3-2 Removal of Door "C"

4-3-3 Removal of Door "E"

Disassembly and Reassembly

Upper Hinge

Lower Hinge

Screw

Door "C"

Door "A"

Door "E"

Key Door Spring

Door "E"

Page 10

Samsung Electronics 4-3

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.

1. Take out the glass tray and guide roller from the cavity.

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 and coupler.

7. When replacing the drive motor, be sure to remount it in the correct position with the coupler.

8. Connect all the leads to the drive motor.

9. Screw the drive motor cover to the base plate with a screw driver.

4-4 Replacement of Fuse

4-5 Replacement of Drive Motor

Disassembly and Reassembly

Screw

Drive Motor Cover Base Plate

Thermo Switch

Drive Motor

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.

Page 11

4-6 Replacement of Control Circuit Board

4-6-1 Removal of Control Box Assembly

4-4 Samsung Electronics

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.

3. Remove screws securing the control box assembly.

4. Remove the screw securing the ground tail of the keyboard.

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.

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.

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.

4-6-2 Removal of P.C.B Assembly

4-6-3 Removal of Window Display & Membrane Panel

Disassembly and Reassembly

Control Box

FPC Connector

Screw

Membrane

Panel

Window

Display

Page 12

Samsung Electronics

5. Alignment and Adjustments

5-1 High Voltage Transformer

5-2 Low Voltage Transformer

5-3 Magnetron

5-1

1. Remove connectors from the transformer terminals and check continuity.

2. Normal resistance readings are as follows:

(Room temperature = 20ûC)

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.

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.

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.

Filament Terminals

Secondary

Terminal

Primary Terminals

MODEL

SHV-4370UCI

Secondary 123.5Ω ±10%

Filament Shows Continuity Primary 0.557Ω ± 10%

Terminals Resistance

CE-5574W

1~2(Input) 248.7Ω 4~5(Output17V) 9.55Ω

7~8(Output2.7V) 1.63Ω

Cooling Fins

Gasket Plate

Magnetron Antenna

Page 13

Samsung Electronics

5-4 High Voltage Capacitor

5-5 High Voltage Diode

5-6 Main Relay and Power Control Relay

5-7 Adjustment of Primary Switch, Door Sensing Switch and Monitor Switch

5-2

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.

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.

1. When mounting Primary switch,Interlock Monitor switch and Secondary 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.

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.

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.

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 secondary interlock(door sensing), 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.

Alignment and Adjustments

Door Open Door Closed

Primary switch ∞ 0 Monitor switch (COM-NC) 0 ∞

Door Sensing S/W

∞

Primary Interlock Switch

Lever Door

Body Latch

Door Sensing Switch

Interlock Monitor Switch

Page 14

Samsung Electronics 5-3

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±1ûC).

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 61seconds exactly. (2 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;

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 70 times the of centigrade temperature.

4.187 x 1000 x ∆T+0.88xMcx(T2-T0)

Output Power =

59.81

59.81: Heating Time (sec)

4.187 : Coefficient for Water 1000 : Water (cc)

∆T : Temperature Rise (T2-T1)

Mc : Cylindrical borosilicate glass weight To : Room temperature.

5-8 Output Power of Magnetron

Alignment and Adjustments

CAUTION

MICROWAVE RADIATION

PERSONNEL SHOULD NOT ALLOW EXPOSURE TO MICROWAVE RADIATION FROM MICROWAVE GENERATOR OR OTHER PARTS CONDUCTING MICROWAVE ENERGY.

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±1ûC).

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;

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:

Minimum

Temperature Rise

Heat Distribution = X 100(%)

Maximum

Temperature Rise

The result should exceed 65%.

5-10 Microwave Heat Distribution - Heat Evenness

D/4

Cooking Tray

Beaker

Page 15

Samsung Electronics5-4

Alignment and Adjustments

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 4mW/cm2, after repair or adjustment.

One Minute +

Popcorn

Frozen Dinner

Power Level

Auto Start Hold

Timer More

Less

1 2 3 4 5 6 7

Auto Defrost

Auto Reheat

Clock

Pause Cancel

Start

5-13Leakage Measuring Procedure

5-10 Procedure for Measurement of Microwave Energy Leakage

5-12

. Note on Measurement

5-11 Check for Microwave Leakage

5-13-1 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/cm2after 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

5-13-2 At least once a year have the microwave energy survey meter checked for accuracy by its manufacturer.

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 4mW/cm2.

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.

Maximum allowable leakage is 5mW/cm2. 4mW/cm2is used to allow for measurement and meter accuracy

Page 16

Samsung Electronics

6. Troubleshooting

6-1

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 Check fan motor when thermal cutout is defective. Fuse is OK. 2. Open thermal cutout (Magnetron) No display and no operation at all. 3. Open low voltage transformer Check Ass'y PCB when LVT is defective.

4. Defective Ass'y PCB

No display and no operation at all. 1. Shorted lead wire harness Check adjustment of primary, interlock monitor, Fuse is blown. 2. Defective primary latch switch (NOTE 1) door sensing switch.

3. Defective monitor switch (NOTE1)

4. Shorted HVCapacitor

5. Shorted HVTransformer (NOTE2) 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 1. Key input is not in-Sequence Refer to operation procedure. key input (Program) 2. Open or loose connection of membrane

key pad to Ass'y PCB

3. Shorted or open membrane panel

4. Defective Ass'y PCB Replace PCB main.

1. Off-alignment of latch switches Adjust door and 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 Timer starts countdown but no cause magnetron to lower output and/or microwave oscillation. intermittent oscillation. (No heat while oven lamp and 3. Defective high voltage components Check high voltage component according to

fan motor turn on.) H.V.Transformer component test procedure and replace if it is

H.V.Capacitor defective. 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 Replace PCB main.

Page 17

Samsung Electronics6-2

Troubleshooting

SYMPTOM CAUSE CORRECTIONS

Oven lamp and fan motor turn on 1. Misadjustment or loose wiring Adjust door and latch switches.

of primary latch switch

2. Defective primary latch switch

Oven can program but timer 1. Open or loose wiring of secondary Adjust door and interlock switches. does not start. interlock switch

2. Off-alignment of primary interlock

3. Defective secondary interlock S/W

Microwave output is low;. 1. Decrease in power source voltage. Consult electrician. Oven takes longer time to 2. Open or loose wiring of magnetron cook food. filament circuit. (Intermittent oscillation))

3. Aging of magnetron 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 Defective Ass'y PCB Replace PCB main.

to the plugged in mode. Loud buzzing noise can be heard. 1. Loose fan and fan motor Tighten screws of fan motor.

2. Loose screws on H.V.Transformer Tighten screws of H.V.Transformer.

3. Shorted H.V.Diode Replace H.V.Diode. Turntable motor does not rotate. 1. Open or loose wiring of turntable motor. Check the wire of turntable motor

2. Defective turntable motor. Replace turntable motor. Oven stops operation during cooking 1. Open or loose wiring of primary Adjust door and latch switches.

interlock switch

2. Operation of thermal cutout(Magnetron) Sparks 1. Metallic ware or cooking dishes Inform the customer.

touching on the oven wall.

2. Ceramic ware trimmed with gold or Do not use any type of cookware with

silver powder also causes sparks. metallic trimming.

Uneven cooking Uneven intensity of microwave due to Wrap thinner parts of the food with

its characteristics. 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 Noise may result from the motor. Replace turntable motor. when it starts to operate.

6-1 Electrical Malfunction(continued)

Page 18

Samsung Electronics

7. Exploded Views and Parts List

7-1 Exploded Views

7-1

M21

M22

M23

M24

M25

M26

M11

M13

M14

M15

M12

M16

M17

M18

M19

M20

M28

M10

M27

I 3

I 1

I 2

Page 19

7-2 Main Parts List

7-2 Samsung Electronics

Exploded Views and Parts List

Ref. No. Parts No. Description/Specification Q'ty Remarks

M 1 DE70-30128A PANEL-OUTER;SECC T0.6 W351.7 L1014.7 MTR 1 M 2 DE91-40100A ASSY NOISE FILTER;SN-U15A 250V 15A SECA 1 M 3 DE39-20037E ASSY POWER CORD;SJT AWG16 GRY 230V50HZ L135 1 M 4 DE31-30031B FAN-MOTOR;SMF437UA 120V/60HZ ASSY-FAN-MO 1 M 5 DE39-40699A WIRE HARNESS-A;120V60HZ MR4381G R/V MODEL 1 M 6 DE47-20009A THERMOSTAT;CS-7SA(160/60) 187Y 250V7.5A 160 1 M 7 DE03-30029A MAGNETRON;OM75SH(31)ESS 1 M 8 4713-001012 LAMP-INCANDESCENT;130V,-,40W,ORG,B/L,-,2 1 M 9 DE71-60010A COVER-AIR;PP(TB53) T1.7 WHT 64G M745 1 M 10 DE93-20001D ASSY BODY LATCH;2ND-SEA MW4370W 1 M 11 DE66-90013A LEVER-DOOR;POM(F20-01) NTR MW5630T 1 M 12 DE26-10113A TRANS-H.V;SHV-4370UC1 120V 60HZ DPC 2080V 1 M 13 2501-001018 C-OIL;800nF,2100V,35X54X70,20mm,BK 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 DE74-20102B TRAY-COOKING;GLASS T5.0 PI288 780G M745 1 M 17 DE92-90436A ASSY-GUIDE ROLLER;MW4370W 1 M 18 DE67-60002A COUPLER;PPS 5GR BRN M97G45 1 M 19 DE61-40017A FOOT;PP(A353) BLK MW5630T 2 M 20 DE80-10117A BASE-PLATE;SGCC1-Z T0.8 W340 L550 MTR43 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 MR4371G GRY 1 M 24 ASSY DOOR;PUSH D-GRAY MW4371G 1 M 25 DE61-80004A HINGE-LOWER;SCP1 T2.3 ZN-COATING BLK 1 M 26 DE61-80005A HINGE-UPPER;SCP1 T2.3 BLK ZN-COATING 1 M 27 DE47-20008A THERMOSTAT;PW2N-52JC 100/60 250V/7.5A H 1 M 28 DE63-90035G CUSHION-RUBBER;DFA20 T2 W190 L100 BLK 1 M 29 DE72-50094A DUCT-AIR;SGCC1-Z T0.6 MR4381G(2ND 1

: Option Parts

: Warning

:Electrostatically Sensitive Devices

Page 20

Samsung Electronics 7-3

7-3 Door Parts List

Ref. No. Parts No. Description/Specification Q'ty Remarks

D 1 DE64-40014B DOOR-A;ABS (HR0370) T3 MW4371G 1 D 2 DE64-40006A DOOR-KEY;POM(TC3005) T2.0 12GR BLK CE945G 1 D 3 DE61-70033A SPRING-KEY;ES HSWR10 PI0.6 D6.0 L22.3 BL 1 D 4 DE67-20151E SCREEN-DOOR;PET T1.1888 W166 L305 NO-BEDA 1 D 5 DE92-50126B ASSY DOOR-E;COATING BLK CE745G 1 D 6 DE64-40008B DOOR-C;PP T1.5 BLK CE745G 1 D 7 DE01-00003A FILM-DOOR;PE-FILM T0.15 W143 L265 M745 1

7-4 Control Parts List

Ref. No. Parts No. Description/Specification Q'ty Remarks

C 1 DE66-20010B BUTTON-PUSH;ABS D-GRY ME4371G 1 C 2 DE61-70076A SPRING-BUTTON;HSWR PI0.6 1 C 3 DE34-10202T SWITCH-MEMBRANE;PET MR4381G/XAA SEA 1 C 4 DE72-70009B CONTROL-PANEL;ABS (VH-0853) 173.5G GRY MW437 1 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

C 7 DE93-30384B ASSY CONTROL-PANEL;N-DESIGN D/GRY MW4371G 1

7-5 Body Latch Parts List

7-6 Installation Parts List

Ref. No. Parts No. Description/Specification Q'ty Remarks

B 1 DE66-40001A LATCH-BODY;POM(F20-02) 40GR NTR 1 B 2 3405-000178 SWITCH-MICRO;250V,15A,200gf,SPST-NO 3 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

Ref. No. Parts No. Description/Specification Q'ty Remarks

I 1 DE64-90157A TRIMMER-UPPER;SECC T0.8 W150 L90 MTR43 1 I 2 DE64-90158A TRIMMER-LOWER;SECC T0.8 W150 L80 BLK MTR 1 I 3 DE72-50094A DUCT-AIR;SGCC1-Z T0.6 MR4381G(2NG 1

Exploded Views and Parts List

Page 21

Parts No. Description / Specification Q'ty Remarks

DE60-10066A SCREW-TAP TH;TH M4 L8 FEFZY 2-SLOT 1 MEM-PN DE60-10069A SCREW-TAP TH;TH M4 L10 FRFZY 4 B-PLTE DE60-10069A SCREW-TAP TH;TH M4 L10 FRFZY 1 CV/AIR DE60-10080A SCREW-WASHER;M5 L12 2S 4 HVT DE60-10080A SCREW-WASHER;M5 L12 2S 4 MGT DE60-10053A SCREW-TAP PH;PH M4 L10 FEFZY 1 CV-TCO DE02-00029A TAPE-SCOTCHPAR;POLYESTER 3M-893 W50 1 DE60-10082H SCREW-A;2S-4X12 TOOTHED 2 BD-LAT DE60-10082H SCREW-A;2S-4X12 TOOTHED 2 CON-BX DE60-10082H SCREW-A;2S-4X12 TOOTHED 4 OUT-PN DE60-10045A SCREW-TAP PH;PH M3 L6 FEFZY 2 MGT-TC DE60-10053A SCREW-TAP PH;PH M4 L10 FEFZY 1 FUSE-H DE60-10053A SCREW-TAP PH;PH M4 L10 FEFZY 2 M/GEAR DE60-10066A SCREW-TAP TH;TH M4 L8 FEFZY 2-SLOT 1 B/HVC DE60-10082H SCREW-A;2S-4X12 TOOTHED 1 P-CO-E DE60-10082H SCREW-A;2S-4X12 TOOTHED 2 CV/BLW DE60-10082H SCREW-A;2S-4X12 TOOTHED 1 B/DR-M DE60-10088A SCREW-TAP PH;PH M3 L8 FEFZY PLAIN 2 P.C.B DE60-10082A SCREW-A;M4 L12 2S TOOTHED 4 OUT-PN DE60-10082A SCREW-A;M4 L12 2S TOOTHED 1 B/DR-M DE60-10082A SCREW-A;M4 L12 2S TOOTHED 2 CON-PA DE60-10012A SCREW-TAP TITE;TH + 3 M4 L10 SWR10 ZPC2 2 HI-UPP DE60-10082A SCREW-A;M4 L12 2S TOOTHED 1 P-CO-E DE60-10012A SCREW-TAP TITE;TH + 3 M4 L10 SWR10 ZPC2 2 HI-LOW

7-4 Samsung Electronics

7-7 Standard Parts List

Exploded Views and Parts List

Page 22

8. P.C.B Diagrams

8-1 P.C.B Diagrams

Samsung Electronics 8-1

Page 23

8-2 Samsung Electronics

Parts No. Description / Specification Q'ty Remarks

0401-001002 DIODE-SWITCHING;1N4148M,100V,200mA,500mW 16 D05~20 0402-000559 DIODE-RECTIFIER;D4G,400V,1A,T-1 1 D01,2,4 0501-000283 TR-SMALL SIGNAL;-,PNP,400mW,TO-92,TP,120 1 Q08 1405-000129 VARISTOR;270V,4500A,17x12mm,TP 1 ZNR1 2202-000121 C-CERAMIC,MLC-AXIAL;100pF,10%,50V,Y5P,1. 1 C09 2202-000127 C-CERAMIC,MLC-AXIAL;10nF,+80-20%,25V,Y5V 1 C10 2202-000780 C-CERAMIC,MLC-AXIAL;100nF,+80-20%,50V,Y5 1 C05 2202-000780 C-CERAMIC,MLC-AXIAL;100nF,+80-20%,50V,Y5 1 C06 2202-000780 C-CERAMIC,MLC-AXIAL;100nF,+80-20%,50V,Y5 1 C07 2202-000780 C-CERAMIC,MLC-AXIAL;100nF,+80-20%,50V,Y5 1 C11 2401-000247 C-AL;100uF,20%,10V,GP,6.3x11mm,5mm, 1 C14 2401-000466 C-AL;10uF,20%,35V,GP,5x7mm,5mm, 1 C08 2401-001412 C-AL;470uF,20%,35V,GP,10x16,5mm,TP 1 C01 2401-001412 C-AL;470uF,20%,35V,GP,10x16,5mm,TP 1 C02 2802-000161 RESONATOR-CERAMIC;4MHz,0.5%,TP,10.0x5.0x 1 X-TAL 3501-001014 RELAY-POWER;24V,21.8mA,17A,1FormA,20mS,8 1 RY02 3501-001016 RELAY-MINIATURE;JV24-KT 24V,12.5MA,5A 1F 1 RY01 3708-000529 CONNECTOR-FPC/FC/PIC;FCZ254-14SL,BLK 14P 1 CON05 3711-000881 CONNECTOR-HEADER;SMW250-03,WHT BOX,3P,1R 1 CON04 A1000-0218 R-CARBON;RD 1/8 T 221-J 1 R09 A1000-0220 R-CARBON;RD 1/8 T 621-J 1 R08 A1000-0225 R-CARBON;RD 1/8 T 392-J 8 R16,18,20,26~30 A1000-0228 R-CARBON;RD 1/8 T 103-J 5 R07,10,14,15,19 A1000-0241 R-CARBON;RD 1/8 T 202-J 1 R13 A1000-0327 R-CARBON;RD 1/8 T 471-J 1 R01 A1000-0327 R-CARBON;RD 1/8 T 471-J 1 R02 A1000-0433 R-CARBON;RD 1/8 T 104-J 2 R17,21, A1000-0473 R-CARBON;RD 1/8 T 102-J 1 R05,6,11,12 A1000-0598 R-CARBON;RD 1/8 T 473-J 20 R31~50 A1000-0620 R-CARBON;RD 1/2 T(S) 331-J 2 R03,4 A1104-0763 C-ELEC;CE 04 -40/85 16V T 220-M NP W/2 1 1 C03 A4060-0008 TR-W/RESISTOR;KSR1005 300MW 100MA 50V EB 1 Q1,6,7,9,10 A4060-0009 TR-W/RESISTOR;KSR2005 300MW -100MA -50V 1 Q2~5 A4106-0154 DIODE-ZENER;TZP5.1B 5.1/5.7V 40MA T 1W 3 ZD1~3 A6010-0461 CONNECTOR-WAFER;YW396-04V WHT 1 CON01 DE07-10035A V.F.DISPLAY;SVM-07SS10 SEA 1 VFD1 DE09-30459A IC-MCU;MB89143AP-159 8K DIP 64PIN 1 IC01 DE13-20009A IC;KA7533 DIP 1 IC02 DE26-20144A TRANS-L.V;DN-5574W,CE-5574W 120V 60HZ AC 1 LVT1 DE30-20016A BUZZER;CBE2220BA STICK 1 BUZ1 DE39-60001A WIRE-SO COPPER;PI0.6 SN T 52MM 25 J01~25 DE41-10330A P.C.B-MAIN;FR-1 T1.6 W88 L163 USA-2ND 1 PCB DE61-90053A HOLDER-DIGITRON;PP-JI350 7G BLK 1

8-2 P.C.B Parts List

P.C.B Diagrams

Page 24

9. Schematic Diagrams

9-1 Schematic Diagrams

9-1

VARISTOR

L.V.TRANS

LAMP

MAIN RELAY

POWER RELAY

(SECONDARY INTERLOCK)

PRIMARY S/W

CAVITY

TCO

FAN

MOTOR

D/MOTOR

MONITOR SWITCH

H. V. TRANS

H. V. CAPACITOR

H. V. DIODE

F FA

MAGNETRON

POWER CORD AC 120V/60Hz

(N)

(L)

BLK

BLU

BLK

BLKBLKBLK

BLK

YEL

WHT

1. INPUT : 120V 60HZ

2. DOOR : OPEN

3. LAMP : ON

4. : P.C.B PATTERN

5. : P.C.B IN/OUT POINT

WHT : WHITE BLK : BLACK YEL : YELLOW BLU : BLUE ORG : ORANGE G : GREEN

MGT TCO

COM

120V

130V 40W

21V

FM DM

ASSY CHOKE P.C.B

FUSE

WHT

GND

0.9mH

500K

2200pF2200pF

BLK BLK

BLK

WHT

BLK BLU

BLK

ORG

COM

ORGNO

COM

DOOR SENSING SWITCH

INTERLOCK MONITOR SWITCH

PRIMARY INTERLOCK SWITCH

(CON1)

RED

ORG

WHT

BLK

MAGNETRON

HIGH VOLTAGE DIODE

TO CHASSIS

FA F

HIGH VOLTAGE TRANSFORMER

HIGH VOLTAGE CAPACITOR

BLK

RED

ORG

WHT

SYMBOL COLOR

BLU

BLK

RED

ORANGE

WHITE

BLUE

BLACK

Samsung Electronics