MICROWAVE OVEN
SERVICE MANUAL
MODEL: MV-1525W,
CAUTION
http://www.LGEservice.com
BEFORE SERVICING THE UNIT, READ THE
SAFETY PRECAUTIONS IN THIS MANUAL.
MV-1525B
CAUTION
SAFETY PRECAUTIONS
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.
• Proper operation of the microwave ovens requires that the magnetron be assembled to the
wave guide and cavity. Never operate the magnetron unless it is properly installed.
• Be sure that the magnetron gasket is properly installed around the dome of the tube whenever
installing the magnetron.
• Routine service safety procedures should be exercised at all times.
• Untrained personnel should not attempt service without a thorough review of the test
procedures and safety information contained in this manual.
FOREWORD
Read this Manual carefully. Failure to adhere to or observe the information in this Manual may result in exposing
yourself to the Microwave Energy normally contained within the oven cavity.
TABLE OF CONTENTS
(Page)
SAFETY PRECAUTIONS ......................................................................................................... Inside front page
SPECIFICATIONS.......................................................................................................................................... 1-1
CAUTIONS..................................................................................................................................................... 2-1
INSTALLATIONS............................................................................................................................................ 3-1
OPERATING INSTRUCTIONS....................................................................................................................... 4-1
CONTROL PANEL ................................................................................................................................. 4-1
CONTROL PANEL INSTRUCTIONS ..................................................................................................... 4-2
OVERALL CIRCUIT DIAGRAM...................................................................................................................... 5-1
SCHEMATIC DIAGRAM......................................................................................................................... 5-1
MATRIX CIRCUIT FOR TOUCH KEY BOARD...................................................................................... 5-2
GENERAL INFORMATION FOR SERVICE................................................................................................... 6-1
GENERAL PRECAUTIONS IN USE ...................................................................................................... 6-1
TRIAL OPERATION ............................................................................................................................... 6-1
FEATURES AND SPECIFICATIONS FEATURES................................................................................. 6-1
SERVICE INFORMATION ............................................................................................................................. 7-1
PRECAUTIONS AND REPAIR SERVICE TIPS..................................................................................... 7-1
MICROWAVE LEAKAGE TEST............................................................................................................. 7-2
POWER OUTPUT MEASUREMENT ..................................................................................................... 7-3
DISASSEMBLY INSTRUCTIONS .......................................................................................................... 7-4
INTERLOCK SYSTEM .......................................................................................................................... 7-12
INTERLOCK CONTINUITY TEST.......................................................................................................... 7-14
TEST AND CHECKOUT PROCEDURES AND TROUBLE SHOOTING................................................ 7-15
A. TEST PROCEDURES................................................................................................................ 7-15
B. CHECKOUT PROCEDURES..................................................................................................... 7-18
C. TROUBLE SHOOTING.............................................................................................................. 7-21
EXPLODED VIEW.......................................................................................................................................... 8-1
REPLACEMENT PARTS LIST............................................................................................................... 8-8
SCHEMATIC DIAGRAM OF PCB .......................................................................................................... 8-15
PRINTED CIRCUIT BOARD .................................................................................................................. 8-16
PCB PARTS LIST................................................................................................................................... 8-17
1-1
Rated Power Consumption 1,500W maximum (Microwave oven only)
1,600W maximum (Microwave oven+Cook top lamps+Ventilation fan)
Microwave Output
1000W (IEC 705 TEST PROCEDURE)
Adjustable 100W through 1000W, 10 steps
Frequency 2,450 MHz
+
_
50 MHz
Power Supply 120 VAC, 60 Hz
Rated Current 13 Amp. (Microwave oven only)
14 Amp. (Microwave oven+Cook top lamps+Ventilation fan)
Magnetron Cooling Forced Air Cooling
Rectification Rectification Voltage Double Half-Wave
Door Sealing Choke System
Safety Devices Magnetron Thermal Fuse:
Open at 109
°
C
+
_
4°C
Oven Cavity Thermostat:
Open at 110
°
C
+
_
50°C
Fuse(20A)
Primary Interlock Switch
Secondary Interlock Switch
Interlock Monitor
Magnetron 2M246-310GF or 2M248E
High Voltage Capacitor Capacitor: 1.0µF, 2.1 KV AC
High Voltage Diode Diode; 350mA, 9.0 KV
Cook top Lamp 125 V, 30 W or 40 W
Cavity Lamp 125 V, 30 W or 40 W
Timer Digital, up to 99 mim. 99 sec. (in each cooking stage)
Tray Tempered Safety Glass
Overall Dimensions 29
15
/16”(W)x167/16”(D)x153/8”(H)
Oven Cavity Size 19
7
/8”(W)x145/32”(D)x815/16”(H)
Effective Capacity of Oven Cavity 1.5 Cu.ft.
Accessories Owner’s Manual & Cooking Guide, Installation Manual,
Exhaust Adapter, Exhaust Damper, Mounting Kit and Two
Filters, Rotating Ring Assembly, Metal Rack.
SPECIFICATIONS
2-1
CAUTIONS
• DO NOT operate on a 2-wire extension cord during
repair and use.
• NEVER TOUCH any oven components or wiring during
operation.
• BEFORE TOUCHING any parts of the oven, always
remove the power plug from the outlet.
• For about 30 seconds after the oven stops, an electric
charge remains in the high voltage capacitor. When
replacing or checking, you must discharge the high
voltage capacitor by shorting across the two terminals
with an insulated screwdriver.
•
Remove your watches whenever working close to or
replacing the Magnetron.
• DO NOT touch any parts of the control panel circuit. A
resulting static electric discharge may damage this
P.C.B.
• NEVER operate the oven with no load.
• NEVER injure the door seal and front plate of the oven
cavity.
• NEVER put iron tools on the magnetron.
• NEVER put anything into the latch hole and the interlock
switches area.
• Proper operation of the microwave oven requires that
the magnetron be assembled to the waveguide and
cavity. Never operate the magnetron unless it is
properly installed.
• Be sure that the magnetron gasket is properly
installed around the dome of the tube whenever
installing the magnetron.
Unlike other appliances, the microwave oven is
high-voltage and high-current equipment.
Though it is free from danger in ordinary use,
extreme care should be taken during repair.
THE OVEN IS TO BE SERVICED ONLY
BY PROPERLY QUALIFIED SERVICE
PERSONNEL.
MICROWAVE RADIATION
Personnel should not be exposed to the
microwave energy which may radiate from the
magnetron or other microwave generating
device if it is improperly used or connection.
All input and output microwave connections,
waveguide, flange, and gasket must be secure
never operate the device without a microwave
energy absorbing load attached.
Never look into an open waveguide or antenna
while the device is energized.
Gasket
ANTENNA
COOLING FIN
MAGNETRON
CHASSIS GROUND
FILAMENT
TERMINALS
MAGNETRON
3-1
INSTALLATIONS
PRECAUTIONS ON INSTALLATION
A. Plug the power supply cord into a 120V AC, 60Hz,
single-phase power source with a capacity of 15A
or 20A.
B. Avoid placing the unit in a location where there is
direct heat or splashing water.
C. Install the unit on the mounting plate firmly.
D. Place the unit as far away as possible from TV,
radio, etc. to prevent interference.
GROUNDING INSTRUCTIONS
For personal safety, this appliance must be fully
grounded at all times.
In the event of an electrical short circuit, grounding
reduces the risk of electrical shock.
The plug must be plugged into an outlet that is
properly installed and grounded.
BEFORE YOU BEGIN, READ THE FOLLOWING INSTRUCTIONS COMPLETELY AND CAREFULLY.
WARNING
Improper use of the grounding plug can result in a
risk of electric shock.
Do not, under any circumstances, cut or remove the
third ground prong from the power cord plug.
CAUTION
This unit is equipped with a 3-prong plug for your
safety. If the wall outlet is a grounded 3-hole type,
the unit will be grounded automatically.
Plug with Ground
Prong
Properly Polarized
and Grounded
Outlet
CONTROL PANEL
4-1
OPERA TING INSTRUCTIONS
CUSTOM
COOK
TURNTABLE
ON/OFF
FAN
HI/LO/OFF
LIGHT
HI/LO/OFF
KITCHEN
TIMER
CUSTOM
SET
CLOCK
AM/PM
LIGHT TIMER
AM/PM
POTATO
PIZZA
RICE
DINNER
PLATE
SOUP
SAUCE
FROZEN
ENTREE
BACON
FRESH
VEGETABLE
FROZEN
VEGETABLE
POPCORN
BEVERAGE
CASSEROLE
POWER
HELP
HOLD
WARM
AUTO TOUCH
1
23
4
56
7
8
0
9
Ez OnEz On
DEFROST
MOREMORE
LESSLESS
STOP
CLEAR
START
CONTROL PANEL INSTRUCTIONS
4-2
The entire operation is done by simple touch control
pads.
(1) Display Window
Numbers and letters are shown in the display
window (Vacuum Fluorescent Tube).
Each Indicator Light shows which function is set
and involved in the course of cooking by turning
itself on. Indicator Lights automatically go out
upon completion of cooking.
(2) MORE, LESS Key
Used to add or subtract ten seconds of cooking
time each time pressing it.
(3) POWER Key
Used to select cooking power level.
(4) EZ on Key
Used to cook for one minute at 100% power level.
It can be used to extend cooking time in multiples
of one minute up to 99 minutes.
(5) CLOCK(TIME OF DAY) Key
Used in setting Time of Day.
(6) STOP/CLEAR Key
Used to stop the oven or clear all entries except
Time of Day.
(7) START Key
Touch the START key after setting the desired
cooking times etc. Also touch the START key to
resume cooking after the cooking is temporarily
stopped by opening the door. The key will not
function unless the door is closed.
(8) DEFROST Key
Used to defrost for frozen foods by weight.
(9) AUTO TOUCH
Used to cook the preprogrammed food
automatically.
(10) HELP Key
This HELP key display feature information and
helpful hints.
(11) LIGHT TIMER
Used to set the cooktop light to turn on and off
automatically at any time you want. The light
comes on at the same time every day until reset.
(12) KITCHEN TIMER
Used to set the timer.
(13) TURNTABLE ON/OFF
Touch this pad to turn off the turntable.
“T/TABLE OFF” will appear in the display.
(14) CUSTOM SET Key
Touch this pad to change the oven’s default
setting for sound, clock, display speed, defrost
weight, and demo mode operations.
(15) FAN HI/LO/OFF Key
Touch FAN once for HIGH fan speed, twice for
low fan speed, or threetimes to turn the fan off.
(16) LIGHT HI/LO/OFF Key
Touch LIGHT once for bright light, twice for the
night light, or three times to turn the light off.
5-1
1
RY 1
RY 3
RY 4
RY 5
PH 1
VR 2
PK
(NO)
PRIMARY
SWITCH
(BOTTOM)
(C)
BL
CN 1
RY6 RY2
123
CN 2
RD
1
1
1
2
2
1
2
2
3
3
1
23
456
123456
RD
RD
RD
6 uF
CAPACITOR
RD
S.M F.M
FAN
MOTOR
TURNTABLE
MOTOR
SECONDARY
SWITCH
(TOP)
RD
RD
RD
RDBRBR
BR
(NC)
H.V.TRANSFORMER
H.V.CAPACITOR
MAGNETRON
FA
F
RECTIFIER
CONTROL MODULE
(C)
MONITOR
SWITCH
(MIDDLE)
BK
BK
WH
RESISTOR
BK
BK
BK
GY
15 PIN CONNECTOR(CN 1)
* NOTE
1. DOOR OPENED & COOK OFF MODE.
2. BLUE MARK ON LAMP SOCKET MUST BE CONNECTED
TO LIVE PART(BLACK WIRE).
3. ONLY CERTAIN MODELS USE THE ABSOLUTE HUMIDITY SENSOR.
BK
BK
BK
OVEN LAMP
COOK TOP
LAMPS
O.L
BK
SINGLE PHASE
ONLY
AC 120V
60Hz
BL
BL
BL
C
Hi
Low
BL
GN
LN
BL
PK
PK
YL
GY
YL
YL
WH
WH
WH
WH
WH
WH
WH
C.L C.L
WH
WH
WH
STIRRER
MOTOR
YL
(C)
(NO)
WH
WH
WH
SYMBOL COLOR
WHITE
BLACK
RED
YELLOW
PINK
BLUE
BROWN
GREEN
BK
RD
YL
PK
BL
BR
GN
GREY
GY
WIRE COLORS
13579111315
WH
WH
WH
RD
BK
BK
BK
VENT
MOTOR
V.M
FUSE 20A
MGT
THERMAL
FUSE
(109 C/228 F)
MICRO COMPUTER BOARD
POWER
TRANS
3
5
7
9
11
13
15
OVEN
THERMOSTAT
(110 C/230 F)
BASE
THERMOSTAT
(56 C/133 F)
3 PIN (CN 2)
(For not provided
Temp Probe)
BL
PK
13
T.M
SCHEMATIC DIAGRAM
OVERALL CIRCUIT DIAGRAM
MATRIX CIRCUIT FOR TOUCH KEY BOARD
7654321
FROZEN
VEGETABLE
POPCORN
FAN(VENT)
HI/LO/OFF
HELP N.C 5 0
POTATO
FROZEN
ENTREE
LIGHT
HI/LO/OFF
CUSTOM
SET
DEFROST
61
BEVERAGE
DINNER
PLATE
EZ on CLOCK 7 2
RICE
HOLD
WARM
POWER
KITCHEN
TIMER
FRESH
VEGETABLE
LIGHT
TIMER
N.C 8 3
PIZZA
CASSEROLE
START
STOP/
CLEAR
94
SOUP/
SAUCE
BACON CUSTOM
COOK
LESS MORE N.C
TURNTABLE
ON/OFF
8
9
10
11
12
13
5-2
6-1
GENERAL PRECAUTIONS IN USE
A. Never operate the unit when it is empty.
Operating the oven with no load may shorten the
life of the magnetron. Whenever cooking dry foods
(dried fish, bread, etc.) or a small amount of food,
be sure to put a glass of water into the cooking
compartment. The glass turntable may become hot
after operating, be careful when touching it.
B. Aluminum foil should be avoided because it will
disrupt cooking and may cause arcing. However,
small pieces may be used to cover some parts of
food to slow the cooking. Any aluminum foil used
should never be closer than 2.5 cm to any side wall
of the oven.
TRIAL OPERATION
After installation, the following sequences and results
should be checked carefully.
A. Put a container filled with water (about 1 liter) into
the oven, and close the door tightly.
B. Set cooking time for 10 minutes by touching “1”
and then “0” three times. “1, 0, 0, 0” appears in
the display window.
C. Touch the START key.
Make sure the cavity light comes on. The unit will
begin cooking and the display window will show the
time counting down by seconds.
D. After about 5 minutes, make sure the primary
interlock switch, the secondary interlock switch and
the interlock monitor switch operate properly by
opening and closing the door several times. Touch
the START key each time the door is closed.
E. Continue operating the unit. Two short and a long
beep sound signal is heard when the time is up.
The unit will shut off automatically.
F. Confirm the water is hot.
G. Finally, measure the output power according to
“POWER OUTPUT MEASUREMENT” on
page 7-3.
FEATURES AND SPECIFICATIONS
FEATURES
A. The safety systems incorporated in this model are:
(1) Primary interlock switch
(2) Secondary interlock switch
(3) Interlock monitor switch
(4) Choke system
(5) Magnetron thermal fuse
(6) Oven cavity thermostat
(Note: This thermostat located on the oven
cavity will open and stop the unit from operation
only if a high temperature is reached, such as,
a fire created by overcooking food.)
B. Any one of 10 power output levels ranging 100W to
1000W can be selected by the touch control and
electronic computer system.
GENERAL INFORMATION FOR SERVICE
PRELIMINARY
A. SINCE NEARLY 2,100 VOLTS EXISTS IN SOME
CIRCUITS OF THIS UNIT REPAIRS SHOULD BE
CARRIED OUT WITH GREAT CARE.
The filament leads of magnetron carry High
Voltage with respect to ground. Extreme caution
must be exercised. Never plug the unit into a
power source to determine which component is
defective in high voltage section.
B. TO AVOID POSSIBLE EXPOSURE TO
MICROWAVE ENERGY LEAKAGE, THE
FOLLOWING PRECAUTIONS MUST BE TAKEN
BEFORE SERVICING.
(1) Before the power is applied:
(a) Make sure the primary interlock switch, the
secondary interlock switch and the interlock
monitor switch operate properly by opening
and closing the door several by opening and
closing the door several times.
(b) Make sure the perforated screen and the
dielectric choke of the door are correctly and
firmly mounted.
(2) After power is applied:
(a) Make sure the interlock switch mechanism
is operating properly by opening and closing
the door.
(b) Check microwave energy leakage must bebelow
the limit of 5 mW/cm
2
.
(All service adjustments should be made for
minimum microwave energy leakage
readings).
(3) Do not operate the unit until it is completely
repaired, if any of the following conditions exist.
The unit must not be operated.
(a) The door does not close firmly.
(b) The hinge is broken.
(c) The door seal is damaged.
(d) The door is bent or warped, or there is any
other visible damage on the unit that may
cause microwave energy leakage.
NOTE: Always keep the seal clean.
(e) Make sure that there are no defective parts
in the interlock mechanism.
(f) Make sure that there are no detective parts
in the microwave generating and transmission
assembly (especially waveguide).
(4) The following items should be checked after the
unit is repaired:
(a) The interlock monitor switch is connected
correctly and firmly.
(b) The magnetron gasket is properly positioned
and mounted.
(c) The waveguide and the oven cavity are intact.
(no microwave energy leakage)
(d) The door can be properly closed and the
safety switches work properly.
(e) The unit must stop when the door is opened or
the time is up.
The unit must not be operated with any of the above
components removed or by-passed.
7-1
PRECAUTIONS AND REPAIR SERVICE TIPS
SERVICE INFORMATION
7-2
CAUTIONS
• Be sure to check microwave leakage prior to
servicing the oven if the oven is operative prior to
servicing.
• The service personnel should inform the
manufacture importer, or assembler of any certified
oven unit found to have a microwave emission level
in excess of 5 mW/cm2and should repair any unit
found to have excessive emission levels at no cost to
the owner and should ascertain the cause of the
excessive leakage. The service personnel should
instruct the owner not to use the unit until the oven has
been brought into compliance.
• If the oven operates with the door open, the service
personnel should:
- Tell the user not to operate the oven.
- Contact the manufacturer and CDRH
(Center for Devices and Radiological Health)
immediately.
NOTE: Address on CDRH
Office of Compliance(HFZ-312)
Center for Devices and Radiological
Healthe 1390, Piccard Drive,
Rockville. MD 20850
• The service personnel should check all surface and
vent openings for microwave leakage.
• Check for microwave leakage after every servicing. The
power density of the microwave radiation leakage
emitted by the microwave oven should not exceed
4 mW/cm2. Always start measuring of an unknown field
to assure safety for operating personnel from radiation
leakage.
EQUIPMENT
• TESTER (VOLTS-DC, AC, Ohmmeter)
• Microwave survey meter
- Holaday HI-1500
HI-1501
- Narda 8100
8200
• 600 cc non conductive material beaker (glass or
plastic), inside diameter: approx. 8.5 cm (3
1
/2
in.)
• Glass thermometer: 100°C or 212°F (1 deg scale)
MEASURING MICROWAVE ENERGY
LEAKAGE
• Pour 275±15cc of 20±5°C(68±9°F) water in a beaker
which is graduated to 600 cc, and place the beaker
on the center of the turntable.
• Set the energy leakage monitor to 2,450 MHz and
use it following the manufacturer's recommended
test procedure to assure correct result.
• When measuring the leakage, always use the 2-inch
(5cm) spacer supplied with the probe.
• Operate the oven at its maximum output.
• Measure the microwave radiation using and
electromagnetic radiation monitor by holding the
probe perpendicular to the surface being measured.
Move probe along shaded area.
Probe scanning speed
Less than 2.5 cm/sec. ( 1 in/sec)
MICROWAVE LEAKAGE TEST
MEASUREMENT WITH THE OUTER CASE
REMOVED
(1) When you replace the magnetron, measure for
microwave energy leakage before the outer case
is installed and after all necessary components
are replaced or adjusted. Special care should be
taken in measuring the following parts.
- Around the magnetron
- The waveguide
WARNING: AVOID CONTACTING ANY HIGH
VOLTAGE PARTS.
MEASUREMENT WITH A FULLY
ASSEMBLED OVEN
(1) After all components, including the outer
panels, are fully assembled, measure for
microwave energy leakage around the door
viewing window, the exhaust opening and air
inlet openings.
(2) Microwave energy leakage must not exceed the
values prescribed below.
NOTES:
Leakage with the outer panels removed - less
than 5 mW/cm
2
.
Leakage for a fully assembled oven (“Before the
latch switch (primary) is interrupted”) with the door
in a slightly opened position - less than 2 mW/cm
2
.
NOTE WHEN MEASURING
(1) Do not exceed meter full scale deflection.
(2) The test probe must be removed no faster than
1 inch/sec (2.5cm/sec) along the shaded area,
otherwise a false reading may result.
(3) The test probe must be held with the grip portion
of the handle. A false reading may result if the
operator’s hand is between the handle and the
probe.
(4) When testing near a corner of the door, keep
the probe perpendicular to the surface making
sure the probe horizontally along the oven
surface, this may possibly cause probe damage.
RECORD KEEPING AND NOTIFICATION
AFTER MEASUREMENT
(1) After adjustment and repair of any microwave
energy interruption or microwave energy blocking
device, record the measured values for future
reference. Also enter the information on the
service invoice.
(2) Should the microwave energy leakage not be
more than 2 mW/cm2after determining that all
parts are in good condition, functioning properly
and genuine replacement parts which are listed in
this manual have been used.
(3) At least once a year, have the electromagnetic
energy leakage monitor checked for calibration
by its manufacturer.
(1)
Microwave power output measurement is made with
the microwave oven supplied at its rated voltage and
operated at its maximum microwave power setting
with a load of (1000±5) g of potable water.
(2)
The water is contained in a cylindrical borosilicate
glass vessel having a maximum material thickness of
1/8” (3 mm) and an outside diameter of
approximately 7.6” (190mm).
(3)
The oven and the empty vessel are at ambient
temperature prior to the start of the test.
(4)
The initial temperature (T1) of the water is (10±2)°C
(50°F) It is measured immediately before the water is
added to the vessel. After addition of the water to the
vessel, the load is immediately placed on the center
of the turntable which is in the lowest position and the
microwave power switched on.
(5)
The time T for the temperature of the water to rise by
a value ∆ T of (10±2)°K is measured, where T is the
time in seconds and ∆T is the temperature rise. The
initial and final water temperatures are selected so
that the maximum difference between the final water
temperature and the ambient temperature is 5°K.
(6)
The microwave power output P in watts is
calculated from the following formula :
4187 x (∆T)
T
is measured while the microwave generator is
operating at full power. Magnetron filament heat-up
time is not included. (about 3 sec)
(7)
The water is stirred to equalize temperature
throughout the vessel, prior to measuring the final
water temperature.
(8)
Stirring devices and measuring instruments are
selected in order to minimize addition or removal of
heat.
7-3
WATER LOAD
TURNTABLE
P =
POWER OUTPUT MEASUREMENT
IMPORTANT NOTES:
UNIT MUST BE DISCONNECTED FROM ELECTRICAL OUTLET WHEN MAKING REPAIRS, REPLACEMENTS, ADJUSTMENTS AND CONTINUITY CHECKS. WAIT AT LEAST ONE MINUTE,
UNTIL THE HIGH VOLTAGE CAPACITOR IN THE
HIGH VOLTAGE POWER SUPPLY HAS FULLY
DISCHARGED.
THE CAPACITOR SHOULD BE DISCHARGED BY
USING INSULATED WIRE - I.E. TEST PROBE
CONNECTED TO 10K-OHM RESISTOR IN SERIES
TO GROUND.
WHEN RECONNECTING THE WIRE LEADS TO
ANY PART, MAKE SURE THE WIRING CONNECTIONS AND LEAD COLORS ARE CORRECTLY
MATCHED ACCORDING TO THE OVERALL CIRCUIT DIAGRAM. (ESPECIALLY SWITCHES AND
HIGH VOLTAGE CIRCUIT.)
A. REMOVING POWER AND CONTROL
CIRCUIT BOARD (Figures 1, 2 and 3)
(1) Remove a screw securing the control panel
assembly to the oven cavity.
(2) Remove the control panel with pushing it upward.
(3) Remove the three connectors (CN1, CN2) and
wire leads (Relay2 and Relay6) from the circuit
board.
CAUTION:The relay connector 2(White) and 6(Red)
must be correctly connected Relay 2 and Relay 6 for
each.These two connectors are not interchangeable.
(4) Remove 3 screws securing the circuit board.
(5) Remove the FPC connector from the terminal
socket following “HOW TO REMOVE THE FPC
CONNECTOR” on the next page.
(6) Remove the circuit board from the control bracket
carefully.
7-4
Circuit Board
T
FPC Connector(S1)
Control Bracket
Circuit Board
Relay 2
Relay 6
Figure 1
Figure 2
Figure 3
DISASSEMBLY INSTRUCTIONS
Control Panel
Relay 2
Relay 6
(Relay 6)-Red
(Relay 2)-White
(CN1)
(CN2)
Screw
Power
Transformer
7-5
HOW TO REMOVE THE F.P.C. CONNECTOR
Follow the steps below as illustrated in Figures 4
and 5 to remove the F.P.C. connector.
(1) Hold the edges of the plastic fastener with
thumb and forefinger.
(Figure 4)
(2) Lift up the lever of the plastic fastener from
the terminal socket by lightly pressing the
lever end with forefinger.
(Figure 5)
(3) Remove the F.P.C. connector from the
terminal socket.
HOW TO INSERT THE F.P.C. CONNECTOR
Follow the steps below as illustrated in Figures 6
and 7 to insert the F.P.C. connector.
(1) Insert the F.P.C. connector into the terminal
socket securely with the fingers.
(2) Hold the plastic fastener with thumb and
forefinger of the other hand, and push it
slowly into the terminal socket. (Figure 6)
NOTE: When reconnecting the F.P.C
connector make sure that the holes
on the F.P.C. connector are properly
engaged with the hooks on the plastic
fastener
(3) Lock the level of the plastic fastener into the
hook of the terminal socket securely by
releasing the fingers.
(Figure 7)
Figure 4
Figure 7
Figure 6
Figure 5
Plastic fastener
Plastic fastener
Hook
F.P.C.
Connector
Plastic fastener
Holes
Terminal
socket
F.P.C.
Connector
Hook
Terminal
socket
Holes
F.P.C.
Connector
Terminal
socket
Plastic
fastener
F.P.C.
Connector
Terminal
socket
B. REMOVING THE OUT CASE(Figure 8)
(1) Remove the vent grille by removing two screws
securing it to the out case.
(2) Remove two screws securing it to the front
bracket.
(3) Remove two screws securing it to the air duct.
(4) Remove the mounting plate by turning the two
screws securing it to the out case.
(5) Remove the base plate by removing six screws
securing it to the out case. Remove the Mount,
All from the out case by removing two screws
securing it to the out case and one screw securing
it to the ventilation motor ASS'Y and cavity.
(6) Remove the power cord cover from outcase by
removing a screw.
(7) Remove the power cord to the inner of the out
case with turning power cord and remove the out
case with pushing it back.
Vent Grille
Controller
Mounting
Plate
Door
Out Case
Mount,All
Power cord cover
Figure 8
7-6
7-7
C REMOVING THE DOOR INTERLOCK
SWITCHES (Figures 9,10)
(1) Disconnect the wire leads from the interlock
switches.
(2) Remove two screws securing the Latch Board.
(3) Make necessary replacements and check
microwave energy leakage according to
“ADJUSTMENT PROCEDURE” on page 7-12.
Latch Board
Secondary
Interlock Switch
Interlock
Monitor Switch
Primary
Interlock Switch
Latch Board
WH
(from H.V.Transformer)
YL(from Fan Motor
)
WH
(
from Power Cord)
WH
(
from cooktop lamp
)
Secondary Interlock Switch
Monitor Interlock Switch
Primary Interlock Switch
PK(from P.C.B)
BL
(
from P.C.B)
WH
(from H.V.Transformer)
BR
(from T urntable Motor)
RD
(from H.V.Transformer)
Figure 9
Figure 10
WIRE COLOR
SYMBOL COLOR
WH
BK
BR
RD
BL
PK
GY
N.P.
WHITE
BLACK
BROWN
RED
BLUE
PINK
GREY
Not Provided
D. REMOVING MAGNETRON
(Figures 11 Through 14)
(1) Remove the vent grille by removing two screws.
(Figure 11)
(2) Remove the controller by removing a screw and
disconnect all wire leads. (Figure 11)
(3) Remove the mount all from the out case by
removing two screws securing it to the out case
and one screw securing it to the ventilation motor
ASS'Y and cavity. (Figure 12)
(4) Remove the base plate by removing six screws
securing it to the oven front plate and outcase,
remove the outcase by removing nine screws
securing it to the oven back plate, air duct, and
front bracket. (Figure 13)
(5) Remove four tap tite screws securing the
magnetron to the wave guide. (Figure 14)
(6) Remove the magnetron VERY CAREFULLY.
NOTES:
• When removing the magnetron, make sure that its
dome does not hit any adjacent parts, or it may be
damaged.
• When replacing the magnetron, be sure to install the
magnetron gasket in the correct position and be sure
that the gasket is in good condition.
• After replacing the magnetron, check for microwave
energy leakage with a survey meter Check
microwave energy leakage must be below the limit
of 5 mW/cm2. (All service adjustments should be
made for minimum microwave energy leakage
readings.)
mount, all
Figure 11
Figure 13
Figure 14
Figure 12
7-8
E. REMOVING STIRRER FAN DISK
(Figures 15 and 16)
(1) Remove 1 rivet ASS'Y securing it to the oven
upper plate by using knife blade.
(2) Rotate slightly and pull out the stirrer fan cover.
(3) Remove the stirrer fan disk.
F. REMOVING DOOR (Figure 17)
(1) Remove the vent grille by removing two screws
securing it to the front bracket.
(2) Lift up and push the door.
G. DISASSEMBLING DOOR (Figure 18)
(1) Remove the dielectric choke by using knife
blade or small screw driver, etc.
(2) Remove two screws securing it to the door handle.
CAUTION: Be careful not to damage door seal
plate with the screwdriver.
NOTES:
• After replacing the door, be sure to check that the
primary interlock switch, the secondary interlock
switch and the interlock monitor switch operate
normally.
• After replacing the door, check for microwave energy
leakage with a survey meter. Microwave energy
leakage must be below the limit of 5mW/cm2. (With a
275 ml water load)
7-9
Door Screen
Figure 16
Figure 15
Figure 18
Figure 17
H. ASSEMBLING DOOR
(1) When mounting the door assembly to the oven
assembly, be sure to adjust the door assembly
parallel to the chassis. Also adjust so the door has no
play between the inner door surface and oven frame
assembly. If the door assembly is not mounted
properly, microwaves may leak from the clearance
between the door and the oven.
I. REMOVING THE VENTILATION FAN
ASS'Y
(1) Remove the mounting plate by removing two
screws securing it to the back plate.
(See Figure 19)
(2) Remove the two screws securing the MOUNT,
ALL and one screw securing the ventilation fan
ASS'Y. (See Figure 20-a)
(3) Carefully pull the ventilation motor ASS'Y out of
the microwave oven. (See Figure 20-b)
7-10
MOUNT, ALL
Figure 19
Figure 20-a
Figure 20-b
Space
K. REMOVING THE TURNTABLE MOTOR
(1) Remove the turntable.
(2) Remove the turntable shaft VERY CAREFULLY
with a slotted screwdriver. (Figure 21)
(3) Remove the base plate by removing 6 screws
securing it to the oven cavity. (Figure 22)
(4) Disconnect the leadwire from the turntable motor
terminals.
(5) Remove the 2 screws securing the turntable motor
to the oven cavity ASS'Y. (Figure 23)
NOTES:
• Remove the leadwire from the turntable motor
VERY CAREFULLY.
• Be sure to grasp the connector not the wires when
removing.
K. REMOVING THE STIRRER FAN MOTOR
(1) Remove all screws from out case and remove
the out case.
(2) Remove 5 screws securing the air duct to the
oven cavity, and remove 2 screws securing the
stirrer fan motor to the bracket. (Figure 24)
(3) Lift the air duct and disconnect the leadwire from
the stirrer fan motor. (Figure 25)
(4) Remove the stirrer fan motor.
Wire Leads
Turntable Motor
Figure 23
Figure 21
Figure 22
Figure 24
Figure 25
7-11
7-12
ADJUSTMENT PROCEDURES
To avoid possible exposure to microwave energy
leakage, adjust the door latches and interlock
switches, using the following procedure.
The Interlock Monitor and Primary Interlock Switch act
as the final safety switch protecting the user from
microwave energy. The terminals between “COM” and
“NC” of the Interlock Monitor must close when the door
is opened. After adjusting the Interlock Monitor Switch,
make sure that it is correctly connected.
Mounting of the primary/monitor/secondary switches to
the latch board.
CHECK THE DOOR LATCH AND SWITCH
CLOSING.
NOTE:
The outer cover of the microwave oven is
removed.
(1) Set the microwave oven on its side so that you can
see the latch board and the switches, as shown in
Figure 26-a.
(2) Close the door tightly and check gaps A and B to
be sure they are no more than 1/64” (0.5 mm).
See Figure 26-b for close-up view of gaps A and B
(door latches). If all gaps are less than 1/64”
(0.5 mm), adjustment of the latch board may not
be necessary. Go to Steps 5 and 6 to check the
sequence of the switches.
NOTE:
To correct sequence of the Primary Interlock
Switch, Secondary Interlock Switch and the
Interlock Monitor Switch is very important.
If any gap is larger than 1/64” (0.5 mm), you will
need to adjust the latch board”. Go to step 3
and follow all steps in order.
ADJUST THE LATCH AND SWITCH CLOSING
(3) Loosen the two screws holding the plastic latch
board as shown.
(4) With the oven door closed tightly, move the latch
board upward toward the top of the oven and/or
away from the door latch until the gaps are less
than 1/64” (0.5 mm).
Hold the latch board tightly in this position until you
check the sequence of the switches in steps 5
and 6.
Latch Board
Secondary Interlock Switch
Interlock Monitor Switch
Primary Interlock Switch
LATCH
LATCH BOARD
0-1/64"
0-1/64"
Figure 26-a
Figure 26-b
INTERLOCK SYSTEM
INTERLOCK MECHANISM
The door lock mechanism is a device which has been specially designed to eliminate completely microwave
activity when the door is opened during cooking and thus to prevent the danger resulting from the microwave
leakage.
7-13
TEST THE LATCH AND SWITCH SEQUENCE
(5) Open the oven door slowly. Watch the door latch,
the Secondary Switch. Release Rod and Lever
on the switches to make sure they are zero to the
body of the switches in the following sequence:
- Primary Interlock Switch
- Secondary Interlock Switch
- Interlock Monitor Switch
Adjust the latch board until the switches operate in
this sequence. See Steps 3 and 4.
(6) Close the oven door slowly and be sure it is tightly
closed. Watch the three switches to make sure
they are zero to the body of the switches in the
following sequence:
- Interlock Monitor Switch
- Primary Interlock Switch
- Secondary Interlock Switch
NOTE: The Interlock Monitor Switch is an added
safety check on the Primary and
Secondary Interlock Switches. If the
Primary and Secondary Interlock Switches
allow the oven to operate with the door
open, the Monitor Switch will blow the
fuse.
(7) When you achieve the proper sequence of
switches in Steps 5 and 6, tighten the latch board
screws at that point.
TEST THE MICROWAVE ENERGY LEAKAGE
Make sure the microwave energy leakage is below the
limit of 1mW/cm2 (with a 275 ml water load) and
5mW/cm2 (with a 275 ml water load without the
cabinet) when measured with a survey meter.
7-14
A. PRIMARY INTERLOCK SWITCH TEST
When the door is opened slowly, an audible click
should be heard at the same time or successively
at intervals and the latches should activate the
switches with an audible click.
If the latches do not activate the switches when the
door is closed, the switches should be a adjusted
in accordance with the adjustment procedure.
Disconnect the wire lead from the primary switch.
Connect the ohmmeter leads to the common
(COM) and normally open (NO) terminal of the
switch. The meter should indicate an open circuit
in the door open condition.
When the door is closed, the meter should indicate
a closed circuit.
When the primary switch operation is abnormal,
make the necessary adjustment or replace the
switch only with the same type of switch.
B. SECONDARY INTERLOCK SWITCH TEST
Disconnect the wire lead from the secondary
switch.
Connect the ohmmeter leads to the common
(COM) and normally open (NO) terminals of the
switch. The meter should indicate a open circuit in
the door open condition. When the door is closed,
meter should indicate an closed circuit. When the
secondary switch operation is abnormal, make the
necessary adjustment or replace the switch only
with the same type of switch.
C. MONITOR SWITCH TEST
Disconnect the wire lead from the monitor switch.
Connect the ohmmeter leads to the common
(COM) and normally closed (NC) terminals of the
switch. The meter should indicate closed circuit in
the door open condition. When the door is closed,
meter should indicate an open circuit. When the
monitor switch operation is abnormal, replace with
the same type of switch.
NOTE: After repairing the door or the interlock
system, it is necessary to do this continuity
test before operating the oven.
WARNING : FOR CONTINUED PROTECTION AGAINST EXCESSIVE RADIATION
EMISSION, REPLACE ONLY WITH IDENTICAL REPLACEMENT PARTS.
TYPE NO. SZM-V16-FA-63 OR VP-533A-OF FOR PRIMARY SWITCH
TYPE NO. SZM-V16-FA-62 OR VP-532A-OF FOR MONITOR SWITCH
TYPE NO. SZM-V16-FA-63 OR VP-533A-OF FOR SECONDARY SWITCH
COMPONENTS TEST PROCEDURE RESULTS
SWITCHES Check for continuity of the Door Door
(Wire leads removed) switch with an Ohm-meter open closed
Primary
Switch
Monitor
Switch
Secondary
Switch
NOTE : After checking for the continuity of switches, make sure that they are
connected correctly.
INTERLOCK CONTINUITY TEST
COM
NO
NC
COM
COM
NO
7-15
- CAUTIONS -
- DISCONNECT THE POWER SUPPLY CORD
FROM THE WALL OUTLET WHENEVER
REMOVINGING THE CABINET FROM THE UNIT.
PROCEED WITH THE TESTS ONLY AFTER
DISCHARGING THE HIGH VOLTAGE CAPACITOR
AND REMOVING THE WIRE LEADS FROM THE
PRIMARY WINDING OF THE HIGH VOLTAGE
TRANSFORMER. (SEE FIGURE 27)
- ALL OPERATIONAL CHECKS WITH MICROWAVE
ENERGY MUST BE DONE WITH A LOAD (1 LITER
OF WATER IN CONTAINER) IN THE OVEN.
A. TEST PROCEDURES
COMPONENTS TEST PROCEDURES RESULTS
MAGNETRON
(Wire leads are
removed)
HIGH-VOLTAGE
TRANSFORMER
(Wire leads are
removed)
1) Measure the resistance: Across the
filament terminals of the magnetron
with an ohm-meter on Rx1 scale.
2) Measure the resistance: Between
each filament terminal of the
magnetron and the chassis ground
with an ohm-mater on high test scale.
1) Measure the resistance:
With an ohm-meter on Rx1 scale.
a. Primary winding;
b. Filament winding;
c. Secondary winding;
2) Measure the resistance:
With an ohm-meter on highest scale.
a. Primary winding to ground;
b. Filament winding to ground;
Normal reading:
Less than 1 ohm.
Normal reading:
Infinite ohms.
NOTE: Replace the magnetron, if the
magnetron checks and all of the
high voltage component tests are
good, but the unit still does not heat
a load.
Normal readings:
Approx. 0.3 to 0.5 ohm.
Less than 0.1 ohm.
Approx. 65 to 120 ohms.
Normal readings:
Infinite ohms.
Infinite ohms.
NOTE: A MICROWAVE ENERGY LEAKAGE TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS
SERVICED FOR ANY REASON.
Primary
Winding
Secondary
Winding
Filament
Winding
Figure 27
TEST AND CHECKOUT PROCEDURES, AND TROUBLE SHOOTING
7-16
COMPONENTS TEST PROCEDURES RESULTS
HIGH-VOLTAGE
CAPACITOR
HIGH-VOLTAGE
DIODE
Measure the resistance:
(1) Terminal to terminal
Ohmmeter
Figure 28-a
(2) Terminal to case
Ohmmeter
Figure 28-b
Measure the continuity:
(1) Forward
Ohmmeter
Figure 29-a
(1) Reverse
Ohmmeter
Figure 29-b
Normal reading:
Momentarily indicates several ohms,
and then gradually returns to infinite
ohms.
Abnormal reading:
Indicates continuity or infinite ohms
from the beginning.
Normal readings:
Infinite.
Abnormal reading:
Indicates continuity.
Normal readings:
continuity.
Abnormal reading:
Infinite.
Normal readings:
Infinite.
Abnormal reading:
continuity.
Measure the resistance between terminal
pins of connector KEY CONNECTOR.
NOTE:
When reconnecting the FPC connector,
make sure that the holes on the FPC
connector are properly engaged with hooks
on the plastic fastener.
MATRIX CIRCUIT FOR
TOUCH KEY BOARD
CONNECTOR(KEY CON)
7-17
COMPONENTS TEST PROCEDURES RESULTS
TOUCH KEY
BOARD
RESISTOR
CIMENT
Resistance
value
When When not
touched touched
Less than More than
400 ohms 1 mega ohm
1
2
3
4
5
6
7
8
9
10
11
12
13
FPC CONNECTOR
Top
Figure 31
Figure 30
Figure 32
Normal reading:
Approx. 15 ohm
Abnormal reading:
Infinite
Measure the resistance
7654321
FROZEN
VEGETABLE
8
POTATO
9
BEVERAGE
10
CASSEROLE
11
PIZZA
12
BACON CUSTOM
13
FAN(VENT)
POPCORN
FROZEN
ENTREE
DINNER
PLATE
FRESH
VEGETABLE
RICE
SOUP/
SAUCE
HELP N.C 5 0
HI/LO/OFF
CUSTOM
LIGHT
SET
HI/LO/OFF
EZ on CLOCK 7 2
LIGHT
N.C 8 3
TIMER
STOP/
START
CLEAR
LESS MORE N.C
COOK
DEFROST
KITCHEN
TIMER
POWER
HOLD
WARM
61
94
TURNTABLE
ON/OFF
7-18
COMPONENTS TEST PROCEDURES RESULTS
RELAY2
Check for continuity of relay 2 with an
ohm-meter.
(Remove wire leads from relay 2 and
operate the unit.)
NOTES:
• A MICROWAVE ENERGY TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS SERVICED FOR
ANY REASON.
• MAKE SURE THE WIRE LEADS ARE IN THE CORRECT POSITION.
• WHEN REMOVING THE WIRE LEADS FROM THE PARTS, BE SURE TO GRASP THE CONNECTOR, NOT
THE WIRES.
B. CHECKOUT PROCEDURES
(1) CHECKOUT PROCEDURES FOR FUSE BLOWING
CAUTION: REPLACE BLOWN FUSE WITH 20 AMPERE FUSE.
Fuse blows immediately after
the door is closed.
Fuse blows immediately after
the door is opened.
Fuse blows when the door is closed and START
key is touched.
Improper operation of the primary interlock, secondary
interlock switches and/or the interlock monitor switch.
Malfunction of the high voltage transformer; the high
voltage capacitor including the diode, the magnetron,
the blower motor or the circuit board.
PROBLEMS CAUSES
POWER
LEVEL
1
2
3
4
5
6
7
8
9
10
4 sec
6 sec
8 sec
10 sec
12 sec
14 sec
16 sec
18 sec
20 sec
22 sec
18 sec
16 sec
14 sec
12 sec
10 sec
8 sec
6 sec
4 sec
2 sec
0
NOTES:
• If the fuse is blown by an improper switch operation, replace the defective switches and the fuse at the same
time. After replacing the defective switches with new ones, make sure that they are correctly connected.
• Check for microwave energy leakage according to INTERLOCK ADJUSTMENT PROCEDURES on page 712 when the primary interlock, secondary interlock switches and/or the interlock monitor switches are
adjusted or replaced.
Relay 2
Relay 6
Figure 33
CAUTION: The relay connector 2(White)
and 6(Red) must be correctly connected
Relay 2 and Relay 6 for each.
These two connectors are not interchangeable.
7-19
(2) CHECKOUT PROCEDURES FOR RELAY.
- PROBLEM (A) -
FAN motor and oven lamp turn on without touching
START key when the door is closed.
Remove the mate connector of I/O
CON from the circuit board.
Does the unit still operate?
GOOD
Replace the
circuit board
Replace
RELAY1
- PROBLEM (B) FAN motor and oven lamp turn on When the door is
closed and START key is touched.
Measure the voltage at pin NO.
35 of U01 or 7of U03
Voltage reading: 0 Vdc
Replace the
circuit board
Defective
RELAY1 or poor
connection of
RELAY1
Defective
RELAY1
Replace
RELAY1 or correct
the connection.
NO
NO
YES
YES
NO
NO
YES
YES
GOOD
7-20
NOTE: A MICROWAVE ENERGY LEAKAGE TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS
SERVICED FOR ANY REASON.
(3) CHECKOUT PROCEDURES FOR CIRCUIT
BOARD
The following symptoms indicate a defective circuit
board.
1) The start function fails to operate but the high
voltage Systems, the interlock switches, the door
sensing and the relay check good.
2) The unit with a normal relay continuously operates.
3) Proper temperature measurement is not obtained.
4) The buzzer does not sound or continues to sound.
5) Some segments of one or more digits do not light
up, or they continue to light up, or segments light
when they should not.
6) Wrong figures appear.
7) The figures of all digits.
8) Some of the indicators do no flicker light up.
9) The clock does not keep time properly.
7-21
PROBLEM - A: “PLEASE SET TIME OF DAY” does not appear in display window when power supply cord is
plugged into wall outlet.
PROBLEM - B: Display does not show correct numbers and/or
correct indications when programmed.
Check: 1. POWER SUPPLY
2. FUSE (See “CHECKOUT PROCEDURES FOR FUSE BLOWING: on page 7-18)
3. OVEN CAVITY THERMOSTAT
1
1
C. TROUBLE SHOOTING
Before following this troubleshooting read “TRIAL OPERATION” on page 6-1.
ƒU “DISPLAY” Problems, “A” thru “C”
ƒU “HELP UP” Problems, “D” thru “E” ƒU “BUZZER Problems, “F”
WH
RD
Measure voltage between pin 1
and pin 3 of connector CN1.
Runs
Runs
Runs
Runs
Runs
0
120
Measure resistance of touch
key board after removing
connector S1.
(See page 7-4 and 7-17)
0
120
120V
Replace
circuit board
Normal
circuit board
Normal
resistance
Voltage
incorrect
Normal
resistance
Resistance
incorrect
Replace touch
key board.
Normal touch
key board
Poor
contact
Correct
seating
Contact
ok
Replace
circuit board
Normal
circuit board
Normal
contact
Check contact
of connector S1
Correct
connections
7-22
PROBLEM - C: Display does not start countdown when START key is touched.
PROBLEM - D: Unit operation seems to be normal but little or
no heating is produced in oven load.
Check: 1. TOUCH KEY BOARD (START KEY FUNCTION)
Check: 1. AIR VENTS
1
1
Check continuity of connector
CN2 between Pin 1(PK) and
pin 3(BL) when the door is
closed
Check operation of fan
motor when START key
is touched.
Continuity
OK
Check contact of
connector S1
Contact
OK
Replace
Circuit board
Correct
seating
Normal
circuit board
Normal
contact
Poor
contact
Normal Primary
switch
No
continuity
Adjust or replace door
sensing switch.
Measure resistance
of H.V.capacitor
(see page 7-16)
Resistance
incorrect
Normal
resistance
Normal
operation
No
operation
Replace
thermostat
Normal
thermostat
Measure resistance
of fan motor
38.8 ohms
Resistance
incorrect
Replace
fan motor
Normal
fan motor
Normal
circuit board
Replace
circuit board
Normal
resistance
Replace H.V.C.
Normal H.V.C.
Normal
magnetron
Replace
magnetron
Normal
operation
No
operation
THERMOSTAT
Jumper across
terminals of
THERMOSTAT by
using jumper lead
Runs
Runs
Runs
Runs
Runs
Runs
Runs
Runs
33
7-23
PROBLEM - E: Unit does not heat up even if display counts down when
START key is touched for “HIGH POWER” cooking.
Check: 1. PRIMARY AND SECONDARY INTERLOCK SWITCHES
2. THERMOSTAT
1
2
Runs
Runs
Runs
Contact
OK
Resistance
incorrect
Check the continuity of
H.V.C. (see page 7-16)
Normal H.V.T.
Resistance
incorrect
Normal H.V.C.
Abnormal
Replace H.V.D.
Normal
Magnetron
Replace
Magnetron
Normal
Normal
H.V.D.
Check the
continuity of H.V.D.
(see page 7-16)
Replace H.V.C.
Normal
resistance
Replace H.V.T.
Normal
resistance
NO
continuity
Replace
circuit board
Normal
circuit board
Poor contact
Replace
circuit board
Normal
circuit board
Contact OK
Normal
contact
Correct
seating
Check contact of
connector S1
Runs
Runs
Runs
Runs
Check the contact of
relay 2(see page 7-18)
Measure resistance of
H.V.Transformer
(see page 7-15)
7-24
PROBLEM - F: No buzzing when touching the key, between
stages or at end of cooking
1
Normal
circuit board
Check normal
operation
circuit board
Replace
circuit board
Runs
7-25
PROBLEM - G: Ventilation fan does not operate when “FAN HIGH/LOW” key is touched.
1
Check: 1. POWER SUPPLY
2. FUSE
Runs
Runs
Runs
Contact
OK
NO
contact
Replace
magnetron thermal fuse
and oven thermostat
Poor contact
Replace
circuit board
Normal
circuit board
Contact OK
Normal
contact
Correct
seating
Check contact
of connector S1
(see page 7-4)
Runs
Replace
ventilation
motor ASS’Y
NO runs
Normal
ventilation
motor ASS’Y
Check the contact of
magnetron thermal
fuse and oven thermostat
8-1
EXPLODED VIEW
DOOR PARTS
1000
1008
1002
1001
1006
1005
1007
1004
1003
W105
8-2
CONTROLLER PARTS
2000
2005
2001
2003
2002
2004
2007
W083
2010
8-3
OVEN CAVITY PARTS
3003
3007
3019
3020
3015
3030
3015
3013
3008
3030
W106
W106
W106
3031
3031
3009
3010
3017
3018
3002
3001
3000
3016
3006
3011
W101
3014
8-4
LATCH BOARD PARTS
4001
4002
4001
4003
4000
W030
8-5
INTERIOR PARTS (I)
TOP
5000
5019
5018
5017
5016
5012
5013
5014
5009
5005
W081
W067
W074
5004
W067
5008
5010
5006
5001
5002
5003
W067
5015
W101
W101
W101
W049
5020
8-6
INTERIOR PARTS (II)
5111
5100
W110
5115
W106
5101
5106
W106
5109
5108
5105
5110
W091
5113
5114
5104
W067
5102
5112
5117
8-7
INSTALLATION PARTS
6011
W141
W106
6002
6001
6005
6003
6008
6006
6004
6007
6013
6012
6009
6010
6007
8-15
SCHEMATIC DIAGRAM OF P.C.B
8-16
PRINTED CIRCUIT BOARD
NO. PART NO. SPECIFICATION Q’TY
CAPACITORS
C63 0CK2210K518 CERAMIC 220pF/50V 1
C64 0CK2210K518 CERAMIC 220pF/50V 1
C65 0CK2210K518 CERAMIC 220pF/50V 1
C66 0CK2230H518 CERAMIC 0.022uF/25V 1
RESISTORS
AR1 0RZ1503G610 ARRAY 150K 1/4W 5% 1
R01 0RD1001F608 CARBON 1.0K 1/6W 5% 1
R02 0RD2202F608 CARBON 22K 1/6W 5% 1
R03 0RD1001F608 CARBON 1.0K 1/6W 5% 1
R04 0RD2001F608 CARBON 2.0K 1/6W 5% 1
R05 0RD1001F608 CARBON 1.0K 1/6W 5% 1
R06 0RD1002F608 CARBON 10K 1/6W 5% 1
R07 0RD1000F608 CARBON 100 1/6W 5% 1
R08 0RD1003F608 CARBON 100K 1/6W 5% 1
R09 0RD1004F608 CARBON 1.0M 1/6W 5% 1
R10 0RD1001F608 CARBON 1.0K 1/6W 5% 1
R21 0RD4702F608 CARBON 47K 1/6W 5% 1
R23 0RD4702F608 CARBON 47K 1/6W 5% 1
R24 0RD4702F608 CARBON 47K 1/6W 5% 1
R27 0RD4702F608 CARBON 47K 1/6W 5% 1
R28 0RD4702F608 CARBON 47K 1/6W 5% 1
R30 0RD0102F608 CARBON 10 1/6W 5% 1
R31 0RD5601F608 CARBON 5.6K 1/6W 5% 1
R32 0RD1001F608 CARBON 1.0K 1/6W 5% 1
R35 0RD1001G608 CARBON 1.0K 1/4W 5% 1
R36 0RD2001F608 CARBON 2.0K 1/6W 5% 1
R37 0RD2001F608 CARBON 2.0K 1/6W 5% 1
R46 0RD4702F608 CARBON 47K 1/6W 5% 1
R50 0RD2202F608 CARBON 22K 1/6W 5% 1
R52 0RD1001F608 CARBON 1.0K 1/6W 5% 1
R53 0RD3900F608 CARBON 390 1/6W 5% 1
R60 0RD5601F608 CARBON 5.6K 1/6W 5% 1
R61 0RD5601F608 CARBON 5.6K 1/6W 5% 1
R62 0RD5601F608 CARBON 5.6K 1/6W 5% 1
R63 0RD5601F608 CARBON 5.6K 1/6W 5% 1
R64 0RD5601F608 CARBON 5.6K 1/6W 5% 1
R65 0RD5601F608 CARBON 5.6K 1/6W 5% 1
8-17
(See Illustration “PRINTED CIRCUIT BOARD”)
PCB PARTS LIST
NO. PART NO. SPECIFICATION Q’TY
INTEGRATED CIRCUITS
U01 0IHI404339U HD404339S-A80S 1
U03 0IKE650040A KID65004AP 1
PH1 0ISH201200A S201DH2 1
TRANSISTORS
Q01 OTR101509AB
“
KTA1015,KTA1266 KEC
”
1
Q02 OTR101509AB“KTA1015,KTA1266 KEC”1
Q20 OTR107009AE KRA107M KEC 1
DIODES
ZD1 0DZ510009AB MTZ5.1B 0.5W 1
ZD2 0DZ560009AB UZ-5.6BS 0.5W 1
D01 0DD400209AA RECTIFIRE 1N4002 1
D02 0DD400209AA RECTIFIRE 1N4002 1
D03 0DD400209AA RECTIFIRE 1N4002 1
D04 0DD400209AA RECTIFIRE 1N4002 1
D08 0DD414809AA SWITCHING 1N4148 1
D11 0DD414809AB SWITCHING 1N4148M 1
D13 0DD414809AB SWITCHING 1N4148M 1
D14 0DD414809AB SWITCHING 1N4148M 1
D15 0DD414809AB SWITCHING 1N4148M 1
D16 0DD414809AB SWITCHING 1N4148M 1
D17 0DD414809AB SWITCHING 1N4148M 1
D20 0DD414809AA SWITCHING 1N4148 1
D21 0DD414809AA SWITCHING 1N4148 1
D30 0DD414809AB SWITCHING 1N4148M 1
CAPACITORS
C02 0CK2230H518 CERAMIC 0.022uF/25V 1
C03 0CK2230H518 CERAMIC 0.022uF/25V 1
C04 0CE2272H638 ELECT. 220uF/25V 1
C05 0CE2272H638 ELECT. 220uF/25V 1
C06 0CE1061K638 ELECT. 10uF/50V 1
C07 0CK1040K518 CERAMIC 0.1uF/50V 1
C09 0CE4761K638 ELECT. 47uF/50V 1
C30 0CK2230H518 CERAMIC 0.022uF/25V 1
C31 0CK2230H518 CERAMIC 0.022uF/25V 1
C60 0CK2210K518 CERAMIC 220pF/50V 1
C61 0CK2210K518 CERAMIC 220pF/50V 1
C62 0CK2210K518 CERAMIC 220pF/50V 1
8-18
(See Illustration “PRINTED CIRCUIT BOARD”)
NO. PART NO. SPECIFICATION QTY
RESISTORS
R66 0RD5601F608 CARBON 5.6K 1/6W 5% 1
R67 0RD2202F608 CARBON 22K 1/6W 5% 1
R68 0RD2202F608 CARBON 22K 1/6W 5% 1
R69 0RD2202F608 CARBON 22K 1/6W 5% 1
R70 0RD2202F608 CARBON 22K 1/6W 5% 1
R71 0RD2202F608 CARBON 22K 1/6W 5% 1
R72 0RD2202F608 CARBON 22K 1/6W 5% 1
R98 0RD0202F608 CARBON 20 1/6W 5% 1
R99 0RD0202F608 CARBON 20 1/6W 5% 1
NO. PART NO. SPECIFICATION QTY
MISCELLANEOUS
CU1 4850W4C001A CUSHION 3.5MM 1
DP1 6302W5A002A
“SVM-07SS15,7-MT-213GN”
1
RY1 6920W2D010A RELAY OJ-SS-112LM 1
RY2 6920W2D014A RELAY DU1PU 1
RY3 6920W2D010A RELAY OJ-SS-112LM 1
RY4 6920WRD007A RELAY VG12HE 1
RY5 6920W2D010A RELAY OJ-SS-112LM 1
RY6 6920W2YD04A RELAY OZF-S-112LM1P 1
BZ1 6908W3YA01A
BUZZER GPB-B-26B2.1ES
1
VR1 CQ33026A VARISTOR INR14D271 1
VR2 CQ33026A VARISTOR INR14D271 1
CN1 6630W5V012A
CON. YW396-15(EVEN VOID)
1
CN2 CQ52212A CON. YW396-03(2VOID) 1
CN3 6630W5YA19E CON. FCZ254-13D 1
CN3 CQ52186A CON. 2635S13V000 *
CN3 6630W5V017D CON.JE501S *
‘*’ : ALTERNATE PARTS.
P/NO : 3828W5S0813
June, 1998
Printed in Korea
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