Samsung GE87W, MW87W-S, MW87W-S/XEG Service Manual

MICROWAVE OVEN

BASIC : GE87W
MODEL : MW87W-S
MODEL CODE : MW87W-S/XEG

Manual

SERVICE

MICROWAVE OVEN FEATURES

1. Cost Reduction for 0.8 cu.ft of Volume

2. Competitive Price

Refer to the service manual in the itself (http://itself.sec.samsung.co.kr/) for the more information.

Contents

1. Precaution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

1-1 Safety precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

1-2 Special Servicing Precautions (Continued) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

1-3 Special High Voltage Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2. Product Specifications & Comparison Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2-1 Table of Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3. Operating Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

3-1 Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

3-2 Features & External Views

3-3 Accessory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

4. Disassembly and Reassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

4-1 Replacement of Magnetron, Motor Assembly and Lamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-2 Replacement of High Voltage Transformer
4-3 Replacement of Door Assembly

4-3-1 Removal of Door “C” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

4-3-2 Removal of Door “E” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

4-3-3 Removal of Key Door & Spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

4-3-4 Reassembly Test

4-4 Replacement of Fuse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

4-5 Replacement of Drive Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

4-6 Replacement of Control Circuit Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

4-6-1 Removal of Control Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

4-6-2 Removal of Ass’y P.C.B

4-6-3 Removal of Key Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

5. Alignment and Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5-1 High Voltage Transformer

5-2 Low Voltage Transformer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5-3 Magnetron . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

5-4 High Voltage Capacitor
5-5 High Voltage Diode

5-6 Main Relay and Power Control Relay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

5-7 Adjustment of

5-8 Output Power of Magnetron . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

5-9 Microwave Heat Distribution - Heat Evenness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

5-10 Procedure for Measurement of Microwave Energy Leakage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

5-11 Check for Microwave Leakage

5-12 Note on Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5-13 Leakage Measuring Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

6. Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6-1 Electrical Malfunction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

6-2 Error Code Numbering Rule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

7. Exploded Views and Parts List

7-1 Exploded Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7-2 Main Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

7-3 Control & Door Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

7-4 Standard Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

8. Schematic Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

9. P.C.B Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

10. Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

11. Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

11-1 Model name standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

11-2 Customer inquiry cases and countermeasures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

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Primary Switch, Door Sensing Switch and Monitor Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

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3
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7

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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.

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 immediately.

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.

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/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.

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.

- 1 -

1-2 Special Servicing Precautions (Continued)

H. V. Diode

H. V. Capacitor

Short

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)

NOTE : Connect the oven to a 20A. When connect-

ing the oven to a 15A, make sure that circuit
breaker can operate.

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.

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.

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

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.

- 2 -

2. Product Specifications & Comparison Charts

2-1 Table of Specifications

Items

Function

General

NEW MODEL

(MW87W)

Capacity 0.8 cu.ft. (23 Liter) 0.8 cu.ft. (23 Liter)

Cavity Dimension
(W X H X D)

Outside Dimension
(W X H X D)

M/W Distribution Turntable Turntable

Door Open Mehtod Handle Handle

Oven Tray

Oven Material Enamel Enamel

Cavity Structure 4 Pieces 4 Pieces

Control Mehtod Tact Tact

Power Level 6 Level 6 Level

Weight(Net)

Weight(Gross)

Loading Q’ty(40ft) 737(Sets / 40ft) 737(Sets / 40ft)

Input Voltage

Input Hertz 50Hz 50Hz

Input Power 1250 1300

High frequency Level 850W 850W

Cooking Time

high frequency Feedingt Side Side

Auto Reheat 4 4

Auto Defrost 4 4

Auto Crusty Cook 4 4

Aqua Clean No Yes

W330 X H211 X D329 W330 X H211 X D329

W489 X H275 X D401.5 W489 X H275 X D406.5

Glass, 288mm Glass, 288mm

13.5kg 13.5kg

15kg 16.5kg

230V 230V

99’ 99’

BASIC MODEL

(GE87W)

- 3 -

3. Operating Instructions

1

2

3

7

4

8

9

6

10

11

5

3-1 Control Panel

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VENTILATION HOLES

LIGHT

DOOR LATCHES

HANDLE

DOOR

COUPLER

ROLLER RING

SAFETY INTERLOCK HOLES

TURNTABLE

275mm

489mm

342mm

401.5mm

206mm

3-2 Features & External Views

- 5 -

3. Operating Instructions

3-3 Accessory

Depending on the model that you have purchased, you are supplied with several accessories that can be used
in a variety of ways.

Description Code No. Q’ty

Coupler DE68-00140A 1

Roller ring DE97-00193B 1

Turntable DE74-20102E 1

- 6 -

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 contained in one assembly).

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.

NOTE 1: When removing the magnetron, make sure that its antenna does not hit any adjacent parts, or it

may be damaged.

NOTE 2: When replacing the magnetron, be sure to remount the magnetron gasket in the correct position

and make sure the gasket is in good condition.

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

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

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4-3 Replacement of Door Assembly

Door "A"

Door "C"

Spring

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.

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.

- 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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