SAMSUNG MR5491GXAA Service Manual

MICROWAVE OVEN

MR5491G / MR5492W

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

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.

Samsung Electronics

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).

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/cm2

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.

CENTRAL SERVICE CENTER

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, 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.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.

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Pretaution

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 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.

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.

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.

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.

1-2	Samsung Electronics

2. Specifications

2-1 Table of Specifications

ITEM	MODEL	MR5491G / MR5492W
TIMER		99 MINUTES 99 SECONDS
POWER SOURCE		120V/60HZ, AC
POWER CONSUMPTION		MICROWAVE : 1,400W
OUTPUT POWER		FROM 100W TO 1000W (10 LEVEL POWER)
		(IEC-705 TEST PROCEDURE)
OPERATING FREQUENCY		2,450MHz
MAGNETRON		OM75PH(31)ESS
COOLING METHOD		COOLING FAN MOTOR
OUTSIDE DIMENSIONS		2011/32(W) x 1111/32(H) x 145/8(D)
NET WEIGHT		35.3 lbs.
SHIPPING WEIGHT		40.8 lbs

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3. Operating Instructions

3-1 Control Panel

Instant Cook Buttons

Instant setting to cook popular foods.

Auto Defrost Button

Set weight of food to be defrosted.

Power Level Selection Button

Sets power to level other than high.

Clock Button

Sets current time.

Pause Canel Button

Press to pause oven or correct a mistake.

One Minute +

Popcorn	Diet Cook
Potato	Baby Food
Fresh	Frozen
Vegetable	Dinner
Auto	Auto
Defrost	Reheat

1 2 3

4 5 6

7 8 9

	Power Level 0	More/Less
	Clock	Kitchen
		Timer

Pause

Cancel Start

One Minute + Button

Press once for every minute of cooking at High power.

Auto Reheat Button

Sets type of dish to be reheated.

Number Buttons

Sets cooking times or amounts.

More/Less Button

Increases or decreases cooking time.

Kitchen Timer Button

Start Button

Press to start cooking.

3-2 Features & External Views

Door	Ventilation Holes	Light
Door Latches
	Glass Plate	Guide Roller

Safety Interlock Holes

Control Panel

Open Door Push

297.3 mm

216.4 mm

369 mm

517 mm	317.4 mm

3-1	Samsung Electronics

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 which are		Cover Air
contained in one assembly).
	Lamp
1. Disconnect all lead wires from the magnetron and lamp.		Fan Motor

2.Remove the air cover.

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

4. Take out the magnetron very carefully.

Screw

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.

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	Magnetron H. V. Trans
remount the magnetron gasket in the correct
position and make sure the gasket is in good	H. V. Capacitor
condition.

4-1 -1 Installation Instructions

CAUTION

•THIS OVEN WAS MANUFACTURED FOR USE IN A RECREATIONAL VEHICLE ONLY.

•THIS OVEN REQUIRES INSTALLATION INTO A CABINET STRUCTURE ONLY.

•THIS OVEN IS NOT DESIGNED FOR USE IN NON-CABINET INSTALLATIONS OR

FREESTANDING APPLICATIONS 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 cabinet)

SCREW

(Trim to outcase)

(Fig. 1)

(Fig. 2)

OVEN INSTALLATION

•ALIGN THE SCREW HOLES ON UPPER AND LOWER TRIMS TO THE HOLES ON THE TOP ENCLOSURE AND BOTTOM ENCLOSURE AND SECURE SCREWS. (Fig. 1)

•PLUG POWER CORD INTO RECEPTACLE, AND SLIDE OVEN INTO CABINET.

•SECURE OVEN TO CABINET THROUGH HOLES IN UPPER AND LOWER TRIMS. (Fig. 2)

•OVEN FEET MUST SIT ON CABINET FLOOR OR SUPPORT RUNNERS THAT ARE FLUSH WITH BOTTOM EDGE OF CABINET OPENING. (Fig. 2)

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