SAMSUNG CO88RBWT Service Manual

MICROWAVE OVEN

CO88R

SERVICE

Manual

MICROWAVE OVEN

CONTENTS

1. Precautions

2. Specifications

3. Operating Instructions

4. Disassembly and Reassembly

5. Alignment and Adjustments

6. Circuit Description

7. Troubleshooting

8. Exploded Views and Parts List

9. PCB Diagrams

10. Schematic Diagrams

BWT

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

1. Precaution

1-1 Safety precautions ( )

Samsung Electronics 1-1

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.

SMSC "JV SAMSUNG SERVICE" LTD RUSSIA, 123308 MOSCOW,MARSHALA ZHUKOVAPR,1,OFFICE 201

SESPO SAMSUNG ELECTRONICS CO.,LTD ST.PETERSBERG OFFICE 5,1TALIANSKAYASTR. ST.PETERSBERG,191011,RUSSIA

SUSC SAMSUNG UKRAINE SERVICE CO.LTD 7 ZHILIYANSKAYA STREET. KIEV 252033. UKRAINE

SALSC SAMSUNG ALMATY SVC CO. 52A MICROREGION ORIBITA-3 ALMATY.480043 REPUBLIC OF KAZAHSTAN

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.

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.

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.

17. 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.

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 for about 30 seconds after disconnection. Short the negative terminal of the highvoltage 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.

1-2

Pretaution

Samsung Electronics

1-2 Special Servicing Precautions (Continued)

1-3 Special High Voltage Precautions

Fig. 1-1 Touch chassis side first then short to the high voltage

capacitor terminal by using a scredriver or jumper wire.

2. Specifications

2-1 Table of Specifications

Samsung Electronics 2-1

TIMER MWO : 60 MINUTES

GRILL : 60 MINUTES

CONVECTION : 90 MINUTES POWER SOURCE 230V 50Hz, AC POWER CONSUMPTION MICROWAVE : 1,200W

GRILL (Upper Heating Element): 1,300W

CONVECTION :

(Upper Heating Element): 1,300W (Lower Heating Element): 1,500W

OUTPUT POWER FROM 70W TO 700W (10 LEVEL POWER)

(IEC-705 TEST PROCEDURE) OPERATING FREQUENCY 2,450MHz MAGNETRON OM75PH(21)ESS COOLING METHOD COOLING FAN MOTOR OUTSIDE DIMENSIONS 498(W) x 330(H) x 461(D)

POWER LEVEL

% Output

10% 70W 4 sec 26 sec 20% 140W 7 sec 23 sec 30% 210W 10 sec 20 sec 40% 280W 13 sec 17 sec 50% 3505W 16 sec 14 sec 60% 420W 19 sec 11 sec 70% 490W 22 sec 8 sec 80% 560W 25 sec 5 sec 90% 630W 28 sec 2 sec

100% 700W 30 sec 0 sec

ON TIME OFF TIME

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3. Operating Instructions

3-1 Control Panel

Samsung Electronics 3-1

DISPLAY

SENSOR REHEAT FEATURE SELECTION

SENSOR COOKING/REHEAT /DEFROSTING TIME ADJUSTMENT BUTTONS

TEMPERATURE CONTROL BUTTONS

POWER LEVEL SELECTION

START / 1MIN + KNOB

CANCELLATION BUTTON

CLOCK SETTING

GRILL MODE SELECTION

MICROWAVE MODE

SELECTION

CONVECTION MODE

SELECTION

AUTOMATIC COOKING

MENU BUTTONS

SENSOR DEFROST

FEATURE SELECTION

3-2 Samsung Electronics

3-2 Features & External Views

Operating Instructions

UPPER HEATING ELEMENT CABINET

VENTILATION SLOTS(TOP)

VENTILATION SLOTS(SIDE) DISPLAY

POWER SUPPLY CORD

PLUG

DOOR HANDLE

DOOR

LOWER HEATING ELEMENT

RUNGS

CERAMIC PROCELAINENAMELED INTERIOR

VENTILATION SLOTS(BACK

ROTATING AXLE

CONTROL PANEL

498MM

461MM

330MM

1. Pull off the plug.

2. Unfasten outer panel bracket- chimney and setting screws (six pieces).

3. Draw the outer panel backward just as making widening both sides of lower part on the back of outer panel.

1. Remove the wiring. (Don't assert force on the lead of the terminal for relay but hold the positive cable to remove it.)

2. Unscrew and remove the panel setting screws(1 piece)

3. When lifting the control panel, the parts like toenail(four locations) will fall down.

4. Draw them as they are to remove them.

1. Remove the operating panel as under (4-2).

2. Remove the connector CN6 above the PC board.

3. Remove four screws for PC board fixing.

4. Remove parts like toenail on the operating panel and then the PC board A.

5. Remove eleven screws for PC board fixing.

6. Remove the PC board B from the operating panel.

7. Remove two screws for volume installing plate attachment.

4. Disassembly and Reassembly

4-1 Removal of Outer Panel

Samsung Electronics 4-1

4-2 Removal of Control Panel

4-3 Replacement of PC board A,B and Volume installation plate

Scr

Screwew

Contr

ol Panel

Screws

Attachment screws(4 pieces)

Screws for PC board B fixing (5 pieces)

Screws for PC board B fixing (6 pieces)

Connector CN6

PC board A

PC board B

Screws(2) for volume installing plate fixing

Volume installing plate

1. Remove the wiring(CN3).

2. Remove the screw(1 piece) for temperature sensor attachment.

3. Remove the temperature sensor.

1. Remove the screw for the sensor attachment on the back of exhaust duct.

2. Remove the gas sensor from the housing.

1. Remove the wiring.

2. Remove the screws(five pieces) for Bkt-cover heater(u) setting.

3. Remove the heater attachment nut(2) with 7mm driver. (Then the gasket stopper and gasket get apart)

4. Press the plate to remove the supportheater(two pieces).

5. Remove the upper heater.

4-4 Replacement of Temperature Seneor

4-5 Replacement of Gas Sensor

4-6 Replacement of Upper Heater(Bkt-cover heater(U), Gasket stopper,Gasket, Plate spring, Support heater)

4-2 Samsung Electronics

Disassembly and Reassembly

Temperature sensor

Temperature sensor attachment screws

GAS sensor

attachment screws

GAS sensor

SUPPORT-HEATER

*Hold on A part and push in direction of B.

PLATE SPRING

CAVITY

*Assembly procedure of gasket

UPPER HEATER

GASKET

GASKET GASKET

STOPPER

BKT-cover heater(U) attachment screw (5 pieces)

Plate spring

SupportHeater

Upper heater(U) attachment nut (2 pieces)

BKT-cover heater(U)

4-7 Replacement of Fuse

Samsung Electronics 4-3

1. Plug off the power cord.

2. Remove fuse cover and the fuse.

After replacement of fuse the fuse cover must be reset.

1. Remove the wiring.

2. Remove the lamp attachment screw(1 piece) and the lamp.

1. Remove the wiring

2. Remove the support-MGT.(Screw 1 piece).

3. Remove the back-panel. (Screw seven piece)

4. Remove the BKT-HVT.(Screw: upper resp. lower each two)

5. Remove the magnetron attachment screws(four pieces) and then the magnetron.

6. Thermo switch is removed together with.

Care the high tension voltage when removing wiring.

4-8 Replacement of Lamp

4-9 Replacement of Magnetron, Thermometal switch

Disassembly and Reassembly

LAMP

LAMP attachment screw

Support MGT

Back Panel

BKT HVT

MAGNETRON

Magnetron attachment

screws(four pieces)

THERMOMETAL

Fuse cover

FUSE

1. Remove the magnetron from the BKT-HVT removed as under (4-9).

2. Remove wiring.

3. Remove BKT-HVR.(Four screws)

4. Remove BKT-HVC.(one screw)

5. Remove high voltage condenser.

6. Remove high voltage transformer.

In case that condenser is charged with electricity make short-circuit between chassis and the high tension circuit.

1. Remove wiring.

2. Remove the noise filter attachment screws with 13mm wrench.

3. Remove the noise filter.

1. Remove spring arm with radio pincers. (left and right each one)

2. Remove arm slider. (left and right each one)

3. Remove the spring-stopper.(one at the lower left).

4. Open the door to remove it pressing lefthand.

4-10 Replacement of High Voltage Trans, Condenser and Diode

4-11 Replacement of Noise Filter

4-4 Samsung Electronics

Disassembly and Reassembly

HIGH VOLTAGE TRANSFORMER

BKT-HVC

HIGH VOLTAGE CONDENSER

HIGH VOLTAGE DIODE

BKT-HVR

BKT-HVT

Noise Filter

attachment screws

ARM-SLIDER(RIGHT)

SPRING-ARM(RIGHT)

Noise Filter

SPRING-ARM (LEFT)

ARM-SLIDER(LEFT)

4-12 Replacement of Door assembly

Method to detach the spring-arm

SPRING-ARM

This part is despatched by turning the radio pincers in the direction of A.

SPRING-STOPPER

1. Remove the wiring(High voltage transformer primary, fan motor, low voltage transformer, Power cord input).

2. Remove the back-panel.(seven screws)

3. Remove the decoration-foot. (two screws)

4. Remove four BKT-holder slider(R,L) attachment screws and eight base-plate attachment screws.

5. Remove the nuts of noise filter.

6. Remove the base-plate.

7. Remove the wiring.

8. Remove the weight sensor assembly.

9. Remover the BKT-weight-sensor B.

10.Remove the lower heater attachment screws.

11.Remove the lower heater.

1. Remove the wiring(fan motor, low tension transformer primary and secondary).

2. Remove the screws(two for fan motor and two for low voltage transformer).

3. Remove the fan heater.

4. Remove the low voltage transformer.

4-13 Replacement of Lower Heater and Weight Sensor assembly

Samsung Electronics 4-5

4-14 Replacement of Fan Motor and Lower Voltage Transformer

Disassembly and Reassembly

Base-plate fixing screws

Lower heater

Holder

Weight sensor assembly

Lower heater fixing screws(two)

Noise filter fixing nut

Decoration

foot

BKT-Holder Slider R L fixing screws

Lower voltage transformer

Fan motor

Fan motor fixing screws(two).

Lower voltage transformer

fixing screws(two).

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