SAMSUNG M183STR Service Manual

MICROWAVE OVEN

M183STR

Manual

SERVICE

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

BWT

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)properdoorclosing, (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 beforetheovenisreleasedtothe 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

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 immediately.

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,besuretorestoreallprotective devices, including: nonmetallic control knobs and compartment covers.

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, 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.

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.

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 emission in excess of 5 mW/cm 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.

CENTRAL SERVICE CENTER

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

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.

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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

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.)

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.

H. V. Capacitor

H. V. Diode

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

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

Never touch any circuit wiring with your hand nor with uninsulated tool during operation.

PRECAUTION

Servicemen should remove their watches whenever working close to or replacing the magnetron.

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2. Specifications

2-1 Table of Specifications

TIMER

POWER SOURCE

POWER CONSUMPTION

OUTPUT POWER

OPERATING FREQUENCY

MAGNETRON

COOLING METHOD

OUTSIDE DIMENSIONS

NET WEIGHT

99 MINUTES 90SECONDS

230V 50Hz

MICROWAVE : 1,250W

FROM 100W 850W ( 10 LEVEL POWER )

2,450MHz

OM75SH(31)ESS

COOLING FAN MOTOR

489275385mm

13.5 kg

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3. Operating Instructions

3-1 Control Panel

3-2 Features & External Views

DOOR LATCHES

HANDLE

DOOR

355mm

489mm

VENTILATION HOLES

TURNTABLE

ROLLER RING

COUPLER

LIGHT

SAFETY INTERLOCK HOLES

m m

5 7 2

180mm

400mm

WINDOW DISPLAY

CONTROL PANEL

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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 capacitors (all of whicharecontainedinoneassembly).

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.

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

positionandmakesurethegasketisingoodcondition.

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.

Servicemen should remove their watches whenever working close to or replacing the magnetron.

PRECAUTION

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4-3 Replacement of Door Assembly

4-3-1 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. Then remove the door assembly.

Door "A"

Door "C"

4-3-2 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.

1. Insertion depth of the thin metal plate should be

0.5mm or less.

4-3-3 Removal of Key Door & Spring

Remove pin hinge from Door "E" Detach spring from Door "E" and key door.

Door "E"

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SAMSUNG M183STR Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual