Sharp R-540DK User manual

R-540DK
R-540DW
Intheinterestofuser-safetytheovenshouldberestoredtoitsoriginal
condition and only parts identical to those specified should be used.
WARNING TO SERVICE PERSONNEL: Microwave ovens con-
tain circuitry capable of producing very high voltage and
current.Contactwiththefollowingpartsmayresultinasevere,
possibly fatal, electrical shock. (High Voltage Capacitor, High
Voltage Power Transformer, Magnetron, High Voltage Recti-
fier Assembly, High Voltage Harness etc..)
TABLE OF CONTENTS Page
PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO
AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY...................INSIDE FRONT COVER
BEFORE SERVICING ......................................................................................................INSIDE FRONT COVER
WARNING TO SERVICE PERSONNEL................................................................................................................1
MICROWAVE MEASUREMENT PROCEDURE ...................................................................................................2
FOREWORD AND WARNING...............................................................................................................................3
PRODUCT SPECIFICATIONS ..............................................................................................................................4
GENERAL INFORMATION...................................................................................................................................4
OPERATION..........................................................................................................................................................6
TROUBLESHOOTING GUIDE ............................................................................................................................10
TEST PROCEDURE............................................................................................................................................12
TOUCH CONTROL PANEL .................................................................................................................................21
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ................................................................29
PICTORIAL DIAGRAM ........................................................................................................................................35
POWER UNIT CIRCUIT ......................................................................................................................................36
LSI UNIT CIRCUIT...............................................................................................................................................37
PRINTED WIRING BOARD .................................................................................................................................40
PARTS LIST ........................................................................................................................................................41
PACKING AND ACCESSORIES .........................................................................................................................43
S5010R540DUW/
R-540DK
R-540DW
MICROWAVEOVEN
MODELS
SERVICEMANUAL
SHARP CORPORATION This document has been published to be used for after
sales service only.
The contents are subject to change without notice.
TOUCH .SCREEN
MINUTE
PLUS STOP
CLEAR START
ONE TOUCH SENSOR
6x6 NO GUESS COOKING
6 Categories + 36 Foods
More From Your Microwave
6 x 6
Reheat Popcorn
Vegetables Meat Poultry
Baked
Potatoes
Fish/
Seafood
Beverage
Center Defrost
3 + 6 Set Up
Frozen
Food Pasta
Grains
123
456
78
0
9
12 : 30 PM
Kitchen
Timer
Minute
Plus +

R-540DK
R-540DW
PRECAUTIONS TO BE OBSERVED BEFOREAND
DURING SERVICING TOAVOID 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.
BEFORE SERVICING
Before servicing an operative unit, perform a microwave emission check as per the Microwave
Measurement Procedure outlined in this service manual.
If microwave emissions level is in excess of the specified limit, contact SHARP ELECTRONICS
CORPORATION immediately @1-800-237-4277.
If the unit operates with the door open, service person should 1) tell the user not to operate the oven
and 2) contact SHARP ELECTRONICS CORPORATION and Food and Drug Administration's
Center for Devices and Radiological Health immediately.
ServicepersonnelshouldinformSHARPELECTRONICSCORPORATIONofanycertifiedunitfound
with emissions in excess of 4mW/cm2. The owner of the unit should be instructed not to use the unit
until the oven has been brought into compliance.

1
R-540DK
R-540DW
WARNING TO SERVICE PERSONNEL
Microwave ovens contain circuitry capable of pro-
ducing very high voltage and current, contact with
following parts
may result in a severe, possibly
fatal, electrical shock.
(Example)
HighVoltageCapacitor,HighVoltagePowerTrans-
former,Magnetron,HighVoltageRectifierAssem-
bly, High Voltage Harness etc..
Read the Service Manual carefully and follow all
instructions.
Before Servicing
1. Disconnectthepowersupplycord ¬,andthenremove
outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
WARNING:RISK OF ELECTRIC SHOCK.
DISCHARGE THE HIGH-VOLTAGE
CAPACITOR BEFORE SERVICING.
The high-voltage capacitor remains charged about 60
secondsaftertheovenhasbeenswitchedoff.Waitfor60
secondsandthenshort-circuittheconnectionofthehigh-
voltagecapacitor (thatisthe connectingleadof thehigh-
voltage rectifier) against the chassis with the use of an
insulated screwdriver.
Whenever troubleshooting is performed the power supply
mustbedisconnected.Itmay,insomecases,benecessary
to connect the power supply after the outer case has been
removed, in this event,
1. Disconnect the power supply cord, and then remove
outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the leads to the primary of the power
transformer.
5. Ensure that the leads remain isolated from other
components and oven chassis by using insulation tape.
6. After that procedure, reconnect the power supply cord.
When the testing is completed,
1. Disconnect the power supply cord, and then remove
outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Reconnect the leads to the primary of the power
transformer.
5. Reinstall the outer case (cabinet).
6. Reconnectthe powersupply cordafter theouter caseis
installed.
7. Run the oven and check all functions.
After repairing
1. Reconnect all leads removed from components during
testing.
2. Reinstall the outer case (cabinet).
3. Reconnectthe powersupply cordafter theouter caseis
installed.
4. Run the oven and check all functions.
Microwave ovens should not be run empty. To test for the
presence of microwave energy within a cavity, place a cup
of cold water on the oven turntable, close the door and set
the power to HIGH and set the microwave timer for two (2)
minutes.When the twominutes haselapsed (timer atzero)
carefully check that the water is now hot. If the water
remainscoldcarryout BeforeServicingprocedureandre-
examine the connections to the component being tested.
When all service work is completed and the oven is fully
assembled,themicrowavepoweroutputshouldbechecked
and a microwave leakage test should be carried out.
Don't Touch !
Danger High Voltage

2
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R-540DW
MICROWAVE MEASUREMENT PROCEDURE
A. Requirements:
1) Microwave leakage limit (Power density limit): The power density of microwave radiation emitted by a microwave oven
shouldnotexceed1mW/cm2atanypoint5cmormorefromtheexternalsurfaceoftheoven,measuredpriortoacquisition
byapurchaser, andthereafter(through theusefullifeof theoven),5 mW/cm2atanypoint 5cmormore fromtheexternal
surface of the oven.
2) Safety interlock switches Primary interlock relay and door sensing switch shall prevent microwave radiation emission in
excess of the requirement as above mentioned, secondary interlock switch shall prevent microwave radiation emission
in excess of 5 mW/cm2at any point 5cm or more from the external surface of the oven.
B. Preparation for testing:
Before beginning the actual measurement of leakage, proceed as follows:
1) Make sure that the actual instrument is operating normally as specified in its instruction booklet.
Important:
Survey instruments that comply with the requirement for instrumentation as prescribed by the performance standard for
microwave ovens, 21 CFR 1030.10(c)(3)(i), must be used for testing.
2) Place the oven tray in the oven cavity.
3) Place the load of 275±15 ml (9.8 oz) of tap water initially at 20±5˚C (68˚F) in the center of the oven cavity.
The water container shall be a low form of 600 ml (20 oz) beaker with an inside diameter of approx. 8.5 cm (3-1/2 in.)
and made of an electrically nonconductive material such as glass or plastic.
Theplacing ofthis standard loadin theoven isimportant notonly toprotect theoven, but alsoto insurethat anyleakage
is measured accurately.
4) Set the cooking control on Full Power Cooking Mode.
5) Close the door and select a cook cycle of several minutes. If the water begins to boil before the survey is completed,
replace it with 275 ml of cool water.
C. Leakage test:
Closed-door leakage test (microwave measurement)
1) Grasptheprobeofthesurveyinstrumentandholditperpendiculartothegapbetweenthedoorandthebodyoftheoven.
2) Move the probe slowly, not faster than 1 in./sec. (2.5 cm/sec.) along the gap, watching for the maximum indication on
the meter.
3) Checkforleakageatthedoorscreen,sheetmetalseamsandotheraccessiblepositionswherethecontinuityofthemetal
has been breached (eg., around the switches, indicator, and vents).
Whiletestingforleakagearoundthedoorpullthedoorawayfromthefrontoftheovenasfarasispermittedbytheclosed
latch assembly.
4) Measure carefully at the point of highest leakage and make sure that the highest leakage is no greater than 4mW/cm2,
and that the secondary interlock switch does turn the oven OFF before any door movement.
NOTE: After servicing, record data on service invoice and microwave leakage report.

3
R-540DK
R-540DW
SHARP ELECTRONICS CORPORATION
SHARP PLAZA, MAHWAH,
NEW JERSEY 07430-2135
SERVICE MANUAL
MICROWAVE OVEN
R-540DK/R-540DW
FOREWORD
This Manual has been prepared to provide Sharp Electronics Corp.
Service Personnel with Operation and Service Information for the
SHARP MICROWAVE OVEN, R-540DK, R-540DW.
It is recommended that service personnel carefully study the entire
text of this manual so that they will be qualified to render satisfactory
customer service.
Check the interlock switches and the door seal carefully. Special
attention should be given to avoid electrical shock and microwave
radiation hazard.
WARNING
Never operate the oven until the following points are ensured.
(A) The door is tightly closed.
(B) The door brackets and hinges are not defective.
(C) The door packing is not damaged.
(D) The door is not deformed or warped.
(E) There is no other visible damage with the oven.
Servicing and repair work must be carried out only by trained service
personnel. DANGER
Certaininitialpartsareintentionallynotgroundedandpresent
a risk of electrical shock only during servicing. Service
personnel - Do not contact the following parts while the
appliance is energized;
HighVoltageCapacitor,PowerTransformer,Magnetron,High
Voltage Rectifier Assembly, High Voltage Harness;
If provided, Vent Hood, Fan assembly, Cooling Fan Motor.
Allthepartsmarked“*”onpartslistareusedatvoltagesmorethan
250V.
Removal of the outer wrap gives access to voltage above 250V.
Allthepartsmarked“∆”onpartslistmaycauseunduemicrowave
exposure, by themselves, or when they are damaged, loosened
or removed.
PRODUCT DESCRIPTION
GENERAL INFORMATION
OPERATION
TROUBLESHOOTING GUIDE AND
TEST PROCEDURE
TOUCH CONTROL PANEL
COMPONENT REPLACEMENT
AND ADJUSTMENT PROCEDURE
WIRING DIAGRAM
PARTS LIST

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R-540DW
ITEM DESCRIPTION
Power Requirements 120 Volts / 13.8 Amperes
60 Hertz
Single phase, 3 wire grounded
Power Output 1200 watts (IEC TEST PROCEDURE)
Operating frequency of 2450MHz
Case Dimensions Width 24"
Height 13-3/8"
Depth 19-1/8"
Cooking Cavity Dimensions Width 17-1/2"
Height 10-1/2"
2.0 Cubic Feet Depth 18-5/8"
Control Complement Touch Control System
Clock ( 1:00 - 12:59 )
Timer (0 - 99 min. 99 seconds)
Microwave Power for Variable Cooking
Repetition Rate;
POWER 100% ................................Full power throughout the cooking time
POWER 90% ................................................... approx. 90% of Full Power
POWER 80% ................................................... approx. 80% of Full Power
POWER 70% ................................................... approx. 70% of Full Power
POWER 60% ................................................... approx. 60% of Full Power
POWER 50% ................................................... approx. 50% of Full Power
POWER 40% ................................................... approx. 40% of Full Power
POWER 30% ................................................... approx. 30% of Full Power
POWER 20% ................................................... approx. 20% of Full Power
POWER 10% ................................................... approx. 10% of Full Power
POWER 0% ................................. No power throughout the cooking time
TOUCH SCREE N, MINUTE PLUS pad, STOP/CLEAR pad
START pad, ONE TOUCH SENSOR pads
6 X 6 NO GUESS COOKING pads
More From Your Microwave pad
Beverage Center pad, Defrost pad, Set Up pad
Oven Cavity Light Yes
Safety Standard UL Listed FCC Authorized
DHHS Rules, CFR, Title 21, Chapter 1, Subchapter J
SPECIFICATION
GENERAL INFORMATION
GROUNDING INSTRUCTIONS
This oven is equipped with a three prong grounding plug. It must be plugged into a wall receptacle that is properly installed
and grounded in accordance with the National Electrical Code and local codes and ordinances. In the event of an electrical
short circuit, grounding reduces the risk of electric shock by providing an escape wire for the electric current.
WARNING: Improper use of the grounding plug can result in a risk of electric shock.
Electrical Requirements
The electrical requirements are a 120 volt 60 Hz, AC only, 15 or 20 amp. fused electrical supply. It is recommended that a
separate circuit serving only this appliance be provided. When installing this appliance, observe all applicable codes and
ordinances.
A short power-supply cord is provided to reduce risks of becoming entangled in or tripping over a longer cord.
Where a two-pronged wall-receptacle is encountered, it is the personal responsibility and obligation of the customer to
contact a qualified electrician and have it replaced with a properly grounded three-pronged wall receptacle or have a

5
R-540DK
R-540DW
grounding adapter properly grounded and polarized. If the extension
cord must be used, it should be a 3-wire, 15 amp. or higher rated cord.
Do not drape over a countertop or table where it can be pulled on by
children or tripped over accidentally.
CAUTION: DO NOT UNDER ANY CIRCUMSTANCES CUT OR RE-
MOVE THE ROUND GROUNDING PRONG FROM THIS
PLUG.
OVEN DIAGRAM
1. One touch door open button.
Push to open door.
2. Door latches.
The oven will not operate unless the
door is securely closed.
3. Removable turntable support.
4. Removable turntable.
The turntable will rotate clockwise or
counterclockwise.
5. Oven lamp.
It will light when oven is operating or
door is opened.
6. Oven door with see-through window.
7. Ventilation openings. (Rear)
8. Auto-Touch control panel.
9. Touch screen.
10.Coupling.
11.Wave guide cover.
12.Power supply cord
3-Pronged
Plug
Grounded
Receptacle Box
Grounding Pin
3-Pronged Receptacle
NOTE:
The directed features are disabled after
three minutes when the oven is not in use.
These features are automatically enabled
when the door is opened and closed or the
STOP/ CLEAR pad is pressed.
1
65
4
210 11
12
9
7
8
3
TOUCH CONTROL PANEL
TOUCH .SCREEN
MINUTE
PLUS STOP
CLEAR START
ONE TOUCH SENSOR
6x6 NO GUESS COOKING
6 Categories + 36 Foods
More From Your Microwave
6 x 6
Reheat Popcorn
Vegetables Meat Poultry
Baked
Potatoes
Fish/
Seafood
Beverage
Center Defrost
3 + 6 Set Up
Frozen
Food Pasta Grains
123
456
78
0
9
12 : 30 PM
Kitchen
Timer
Minute
Plus +
See note

6
R-540DK
R-540DW
OPERATION
DESCRIPTION OF OPERATING SEQUENCE
Thefollowingisadescriptionofcomponentfunctionsduring
oven operation.
OFF CONDITION
Closing the door activates the door sensing switch and
secondary interlock switch. (In this condition, the monitor
switch contacts are opened.)
When oven is plugged in, 120 volts A.C. is supplied to the
control unit (Figure O-1). Page 8
1. "Setclock"key and"Videodemo"keywill beappeared
on the touch screen.
2. Touch"Set clock"key and setthe clockreferring tothe
operation manual.
NOTE: If any keys are not touched for 30 seconds, the
touchscreenwillgoontotheVideoDemomode.To
cancel the Video Demo mode, touch the STOP/
CLEAR pad. And then set the clock.
3. Thetouchscreenwillshowthehomepageaftersetting
the clock.
4. The following is the example of the Home page in the
case the time of the day is set to 12:30 p.m..
NOTE: Evenif the clockis not set,the displaywill show the
Home page by touching the STOP/CLEAR pad
within 30 seconds after plugged in.
COOKING CONDITION
Program desired cooking time by touching the NUMBER
keys on the touch screen. Program the power level by
touching the POWER LEVEL key and then touch the
desired percentage key on the touch screen.
When the START pad is touched, the following operations
occur:
1. The contacts of relays are closed and components
connected to the relays are turned on as follows.
(For details, refer to Figure O-2), Page 8
RELAY CONNECTED COMPONENTS
RY-1 oven lamp/turntable motor/fan motor
RY-2 power transformer
2. 120 volts A.C. is supplied to the primary winding of the
power transformer and is converted to about 3.3 volts
A.C. output on the filament winding, and approximately
2370 volts A.C. on the high voltage winding.
3. The filament winding voltage heats the magnetron
filamentandtheH.V.windingvoltageissenttoavoltage
doubler circuit.
4. The microwave energy produced by the magnetron is
channelled through the waveguide into the cavity feed-
box, and then into the cavity where the food is placed to
be cooked.
5. Upon completion of the cooking time, the power
transformer, oven lamp, etc. are turned off, and the
generation of microwave energy is stopped. The oven
will revert to the OFF condition.
6. When the door is opened during a cook cycle, the
monitorswitch,doorsensingswitch,secondaryinterlock
switch, relay (RY1) and primary interlock relay are
activated with the following results. The circuits to the
turntable motor, the cooling fan motor, and the high
voltage components are de-energized, the oven lamp
remainson,andthedigitalread-outdisplaysthetimestill
remaining in the cook cycle when the door was opened.
7. Themonitorswitchelectrically monitorstheoperationof
the secondary interlock switch and primary interlock
relay and is mechanically associated with the door so
that it will function in the following sequence.
(1) Whenthedooropensfromtheclosedposition,theprimary
interlock relay (RY2) and secondary interlock switch
open their contacts. And contacts of the relay (RY1)
remains closed. Then the monitor switch contacts close.
(2)When the door is closed from the open position, the
monitor switch contacts open first. Then the contacts of
the secondary interlock switch and door sensing switch
close. And contacts of the relay (RY1) open.
Ifthesecondaryinterlock switchandprimaryinterlockrelay
(RY2)failwiththecontactsclosedwhenthedoorisopened,
the closing of the monitor switch contacts will form a short
circuitthroughthemonitorfuse,secondaryinterlockswitch,
relay (RY1) and primary interlock relay (RY2), causing the
monitor fuse to blow.
POWER LEVEL 0% TO 90% COOKING
When Variable Cooking Power is programmed, the 120
voltsA.C.issuppliedtothepowertransformerintermittently
through the contacts of relay (RY-2) which is operated by
the control unit within a 32 second time base. Microwave
power operation is as follows:
VARI-MODE ON TIME OFF TIME
POWER 100% (100% power) 32 sec. 0 sec.
POWER 90% (approx. 90% power) 30 sec. 2 sec.
POWER 80% (approx. 80% power) 26 sec. 6 sec.
POWER 70% (approx. 70% power) 24 sec. 8 sec.
POWER 60% (approx. 60% power) 22 sec. 10 sec.
POWER 50% (approx. 50% power) 18 sec. 14 sec.
POWER 40% (approx. 40% power) 16 sec. 16 sec.
POWER 30% (approx. 30% power) 12 sec. 20 sec.
POWER 20% (approx. 20% power) 8 sec. 24 sec.
POWER 10% (approx. 10% power) 6 sec. 26 sec.
POWER 0% (approx. 0% power) 0 sec. 32 sec.
Minute
Plus + Kitchen Timer
12 : 30 PM
123
456
78
0
9

7
R-540DK
R-540DW
Note: The ON/OFF time ratio does not correspond with
the percentage of microwave power, because
approx. 2 seconds are needed for heating of the
magnetron filament.
SENSOR COOKING CONDITION
Using the Sensor cooking function (See sensor cooking
menus), the food is cooked without figuring time, power
levelorquantity.Whentheovensensesenoughsteamfrom
the food, it relays the information to its microprocessor
which will calculate the remaining cooking time and power
level needed for best results. When the food is cooked,
water vapor is developed. The sensor “senses” the vapor
anditsresistanceincreasesgradually.Whentheresistance
reaches the value set according to the menu, supplemen-
tary cooking is started. The time of supplementary cooking
is determined by experiment with each food category and
input into the LSI.
An example of how sensor works: (BAKED POTATOES)
1. Potatoes at room temperature. Vapor is emitted very
slowly.
2. HeatPotatoes.Moistureandhumidityisemittedrapidly.
You can smell the aroma as it cooks.
3. Sensor detects moisture and humidity and calculates
cooking time and variable power.
Cooking Sequence.
1. TouchoneoftheOneTouchSensorpads(incaseofone
touch sensor).
NOTE: The oven should not be operated on SENSOR
immediately after plugging in the unit. Wait two
minutes before cooking on SENSOR.
2. Thecoilofshut-offrelay(RY-1)isenergized,theturntable
motor, oven lamp and cooling fan motor are turned on,
but the power transformer is not turned on.
3. After about 16 seconds, the cook relay (RY-2) is
energized. The power transformer is turned on,
microwaveenergyis producedandfirst stageisstarted.
The 16 seconds is the cooling time required to remove
any vapor from the oven cavity and sensor.
NOTE: Duringthisfirststage,donotopenthedoorortouch
STOP/CLEAR pad.
4. When the sensor detects the vapor emitted from the
food,thedisplayswitchesovertothe remainingcooking
time and the timer counts down to zero.
At this time, the door may be opened to stir, turn, or
season food.
5. Whenthe timerreaches zero,an audiblesignal sounds.
The shut-off relay and cook relay are de-energized and
the power transformer, oven lamp, etc. are turned off.
6. OpeningthedoorortouchingtheSTOP/CLEARpad,the
timeofdaywill reappearonthedisplayandthe ovenwill
revert to an OFF condition.
The followings are the sensor cooking menus.
Reheat
Popcorn
Baked potatoes
Vegetables
Ground beef or Meat
Boneless Chicken Breast, Bone-in Chicken Pieces and
Ground Poultry or Poultry
Fish / Seafood
Vegetables,Entrees,MainDishesandSnacksofFrozen
food
White Rice and Brown Rice of Pasta Grains
Frozen breakfast food, Meal in cup, Hot dogs in buns,
Soup, Frozen sandwich, Stuffed Acorn Squash,
Ratatouille of More from Your Microwave
MICROWAVE
MICROWAVE
AH SENSOR

8
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R-540DW
Figure O-1. Oven Schematic-Off Condition
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. CLOCK APPEARS ON DISPLAY.
Figure O-2. Oven Schematic-Cooking Condition
120V AC
60 Hz
OVEN
LAMP TURN-
TABLE
MOTOR FAN
MOTOR
MONITOR
SWITCH
H.V. RECTIFIER MAGNETRON
SECONDARY
INTERLOCK
SWITCH
TTM
OL FM
MONITOR
FUSE 20A
CAVITY
TEMP.
FUSE
MAGNETRON
TEMP.
FUSE
A1
A2
COM.
COM.
COM.N.O.
N.C.
N.O.
DOOR
SENSING
SWITCH
(RY-1) (RY-2)
CONTROL UNIT
PRIMARY
INTERLOCK
RELAY
B1 B2
GRN
POWER
TRANSFORMER
CAPACITOR 1.0µF
AC 2300V
F3
F1 F2
AH SENSOR
120V AC
60 Hz
OVEN
LAMP TURN-
TABLE
MOTOR FAN
MOTOR
MONITOR
SWITCH
H.V. RECTIFIER MAGNETRON
SECONDARY
INTERLOCK
SWITCH
TTM
OL FM
CAVITY
TEMP.
FUSE
A1
A2
COM.
COM.
COM.N.O.
N.C.
N.O.
DOOR
SENSING
SWITCH
(RY-1) (RY-2)
CONTROL UNIT
PRIMARY
INTERLOCK
RELAY
B1 B2
GRN
POWER
TRANSFORMER
CAPACITOR 1.0µF
AC 2300V
MONITOR
FUSE 20A
MAGNETRON
TEMP.
FUSE
F3
F1 F2
NOTE: Indicates components with potential above 250 V.
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. COOKING TIME PROGRAMMED.
3. VARIABLE COOKING CONTROL "POWER 100 %
PROGRAMMED".
4. "START" PAD TOUCHED.

9
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DESCRIPTION AND FUNCTION OF COMPONENTS
DOOR OPEN MECHANISM
The door is opened by pushing the open button on the
controlpanel,refertotheFigureD-1.Whentheopenbutton
is pushed, the open button pushes up the switch lever, and
then the switch lever pushes up the latch head. The latch
heads are moved upward and released from latch hook.
Now the door will open.
Figure D-1. Door Open Mechanism
DOOR SENSING AND SECONDARY INTERLOCK
SWITCHES
The secondary interlock switch is mounted in the lower
position of the latch hook. The door sensing switch in the
primaryinterlocksystemismountedintheupperpositionof
thelatchhook.Theyareactivatedby thelatch headsonthe
door. When the door is opened, the switches interrupt the
power to all high voltage components. A cook cycle cannot
take place until the door is firmly closed thereby activating
both interlock switches. The primary interlock system con-
sists of the door sensing switch and primary interlock relay
located on the control circuit board.
MONITOR SWITCH
Themonitorswitchisactivated(thecontactsopened)bythe
latch head on the door while the door is closed. The switch
is intended to render the oven inoperative, by means of
blowing the monitor fuse, when the contacts of the primary
interlock relay (RY2) and secondary interlock switch fail to
open when the door is opened.
Functions:
1. Whenthedoorisopened,themonitorswitchcontactclose
(totheONcondition)duetotheirbeingnormallyclosed.At
this time the primary interlock relay (RY2) and secondary
interlock switch are in the OFF condition (contacts open)
due to their being normally open contact switches.
2. As the door goes to a closed position, the monitor switch
contactsarefirstopenedandthenthedoorsensingswitch
and the secondary interlock switch contacts close. (On
openingthedoor,eachoftheseswitchesoperateinversely.)
3. If the door is opened, and the primary interlock relay
(RY2) and secondary interlock switch contacts fail to
open,themonitorfuseblowssimultaneouslywithclosing
of the monitor switch contacts.
CAUTION: BEFORE REPLACING A BLOWN MONITOR
FUSE TEST THE DOOR SENSING SWITCH,
PRIMARYINTERLOCKRELAY(RY2),RELAY
(RY1), SECONDARY INTERLOCK SWITCH
AND MONITOR SWITCH FOR PROPER OP-
ERATION.(REFERTOCHAPTER"TESTPRO-
CEDURE").
NOTE: MONITOR FUSE AND MONITOR SWITCH ARE
REPLACED AS AN ASSEMBLY.
TURNTABLE MOTOR
The turntable motor rotates the turntable located on the
bottomof theoven cavity,so thatthe foodson the turntable
cookevenlyduringcooking.Theturntablemayturnineither
direction.
COOLING FAN MOTOR
The cooling fan motor drives a blade which draws external
cool air. This cool air is directed through the air vanes
surroundingthemagnetronandcoolsthemagnetron.Thisair
is channelled through the oven cavity to remove steam and
vapors given off from the heating of the food. It is then
exhaustedthroughtheexhaustingairventsattheovencavity.
MONITOR FUSE
1. Themonitorfuseblowswhenthecontacts(COM-NO)of
theprimaryinterlockrelay(RY2)andsecondaryinterlock
switchremainclosedwith theovendooropenandwhen
the monitor switch closes.
2. If the wire harness or electrical components are short-
circuited, this monitor fuse blows to prevent an electric
shock or fire hazard.
CAVITY TEMPERATURE FUSE
The cavity temperature fuse located on the top of the oven
cavity,isdesignedtopreventdamagetotheovenbyfire.Ifthe
foodload isovercooked,by eithererrorin cooktimeor defect
in the control unit, the cavity temperature fuse will open.
Undernormaloperation,thecavitytemperaturefuseremains
closed. However, when abnormally high temperatures are
reachedwithintheovencavity,thecavitytemperaturefusewill
open at 302˚F(150˚C) causing the oven to shut down.
NOTE: This is a fuse. It does not reset.
MAGNETRON TEMPERATURE FUSE
Themagnetrontemperaturefuselocatednearthemagnetron
is designed to prevent damage to the magnetron if an over
heated condition develops in the tube due to cooling fan
failure, obstructed air guide, dirty or blocked air intake, etc.
Under normal operation, the magnetron temperature fuse
remains closed. However, when abnormally high tempera-
tures are reached within the magnetron, the magnetron
temperaturefusewillopenat302˚F(150˚C)causing theoven
to shut down.
NOTE: This is a fuse. It does not reset.
Door Sensing
Switch
Monitor Switch
Switch Lever
Secondary Interlock
Switch
Latch Heads
Door

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TROUBLESHOOTING GUIDE
Never touch any part in the circuit with your hand or an uninsulated tool while the power supply is connected.
Whentroubleshootingthemicrowaveoven, it ishelpfultofollowtheSequenceof Operationin performingthe checks.Many
ofthepossiblecausesoftroublewillrequirethataspecifictestbeperformed.Thesetestsaregivenaprocedureletterwhich
will be found in the "Test Procedure "section.
IMPORTANT: If the oven becomes inoperative because of a blown monitor fuse, check the monitor switch, relay (RY1)
primary interlock relay (RY2), door sensing switch and secondary interlock switch before replacing the
monitorfuse.Ifthemonitorfuseisreplaced,themonitorswitchmustalsobereplaced.UsepartFFS-BA016/
KIT as an assembly.
IMPORTANT: Whenever troubleshooting is performed with the power supply cord disconnected. It may in, some cases,
be necessary to connect the power supply cord after the outer case has been removed, in this event,
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the leads to the primary of the power transformer.
5. Ensurethattheleadsremainisolatedfrom othercomponents andovenchassis byusing insulationtape.
6. After that procedure, reconnect the power supply cord.
When the testing is completed
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Reconnect all leads removed from components during testing.
5. Reinstall the outer case (cabinet).
6. Reconnect the power supply cord after the outer case is installed.
7. Run the oven and check all functions.

11
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CK = Check / RE = Replace
SHORT IN POWER CORD SHORT OR OPENED WIRING MAGNETRON POWER TRANSFORMER H.V. RECTIFIER ASSEMBLY HIGH VOLTAGE CAPACITOR CAVITY TEMPERATURE FUSE MAGNETRON TEMPERATURE FUSE PRIMARY INTERLOCK SYSTEM SECONDARY INTERLOCK SWITCH MONITOR SWITCH MONITOR FUSE OVEN LAMP OR SOCKET COOLING FAN MOTOR TURNTABLE MOTOR TOUCH CONTROL PANEL WRONG OPERATION LOW VOLTAGE DIRTY OVEN CAVITY KEY UNIT RELAY (RY1) COMPU DEFROST FOIL PATTERN ON PWB. AH SENSOR
Home fuse or circuit breaker blows when
power cord is plugged into wall receptacle.
Monitor fuse blows when power cord is
plugged into wall receptacle.
All letters and indicators do not appear in
display when power cord is first plugged
into wall outlet.
Touch screen does not operate properly
when STOP/CLEAR key is touched.
(Buzzer should sound and Home Page
should appear in display.)
Oven lamp does not light when door is
opened.
Oven lamp does not go out when door is
closed.
Oven lamp lights but fan motor and
turntable motor do not operate.
Oven does not go into cook cycle when
START pad is touched
Oven seems to be operating but little or
no heat is produced in oven load. (Food
incompletely cooked or not cooked at all
at end of cook cycle.)
Oven goes into a cook cycle but
extremely uneven heating is produced in
oven load (food).
Oven does not cook properly when
programmed for cooking POWER 50%
mode. (Operates properly on cooking
POWER 100 % mode.)
Oven goes into COMPU DEFROST but
food is not defrosted well.
AH sensor does not end during Sensor
cooking condition. (Oven does not shut
off after a cup of water is boiling by
sensor cooking.)
Oven stops at 16 sec. after starting.
RE RE ABCDEEFFGHRE RE CK ICK CK CK JKLMN
TEST PROCEDURE
POSSIBLE CAUSE
AND
DEFECTIVE PARTS
COOKING
CONDITION
CONDITION PROBLEM
OFF
CONDITION
SENSOR
COOKING
CONDITION

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BPOWER TRANSFORMER TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the primary input terminals and measure the resistance of the transformer with an
ohmmeter. Check for continuity of the coils with an ohmmeter. On the R x 1 scale, the resistance of
the primary coil should be less than 1 ohm and the resistance of the high voltage coil should be
approximately 80 ohms; the resistance of the filament coil should be less than 1 ohm.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. To test for an open filament, isolate the magnetron from the high voltage circuit. A continuity check
across the magnetron filament leads should indicate less than 1 ohm.
5. Totestforashortedmagnetron,connecttheohmmeterleadsbetweenthemagnetronfilamentleads
and chassis ground. This test should indicate an infinite resistance. If there is little or no resistance
the magnetron is grounded and must be replaced.
6. Reconnect all leads removed from components during testing.
7. Reinstall the outer case (cabinet).
8. Reconnect the power supply cord after the outer case is installed.
9. Run the oven and check all functions.
MICROWAVE OUTPUT POWER
The following test procedure should be carried out with the microwave oven in a fully assembled
condition (outer case fitted).
HIGH VOLTAGES ARE PRESENT DURING THE COOK CYCLE, SO EXTREME CAUTION SHOULD
BE OBSERVED.
Power output of the magnetron can be measured by performing a water temperature rise test. This test
shouldonlybeusedifabovetestsdonotindicateafaultymagnetronandthereisnodefectinthefollowing
componentsorwiring:siliconrectifier,highvoltagecapacitorandpowertransformer.Thistestwillrequire
a 16 ounce (453cc) measuring cup and an accurate mercury thermometer or thermocouple type
temperature tester. For accurate results, the following procedure must be followed carefully:
1. Fillthemeasuringcupwith16oz.(453cc)oftapwaterandmeasurethetemperatureofthewaterwith
a thermometer or thermocouple temperature tester. Stir the thermometer or thermocouple through
the water until the temperature stabilizes. Record the temperature of the water.
2. Place thecup ofwater inthe oven.Operate ovenat POWER100% selecting morethan 60seconds
cook time. Allow the water to heat for 60 seconds, measuring with a stop watch, second hand of a
watch or the digital read-out countdown.
3. Remove the cup from the oven and again measure the temperature, making sure to stir the
thermometer or thermocouple through the water until the maximum temperature is recorded.
4. Subtractthe coldwatertemperature fromthehot watertemperature.The normalresult shouldbe33
to 62˚F(18.6 to 34.5˚C) rise in temperature. If the water temperatures are accurately measured and
tested for the required time period the test results will indicate if the magnetron tube has low power
output (low rise in water temperature) which would extend cooking time or high power output (high
risein water temperature)which would reducecooking time.Because cooking timecan beadjusted
to compensate for power output, the magnetron tube assembly should be replaced only if the water
temperaturerisetestindicatesapoweroutputwellbeyondthenormallimits.Thetestisonlyaccurate
if the power supply line voltage is 120 volts and the oven cavity is clean.
AMAGNETRON ASSEMBLY TEST

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TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. If the capacitor is open, no high voltage will be available to the magnetron. Disconnect input leads
and check for short or open between the terminals using an ohmmeter.
Checking with a high ohm scale, if the high voltage capacitor is normal, the meter will indicate
continuity for a short time and should indicate an open circuit once the capacitor is charged. If the
above is not the case, check the capacitor with an ohmmeter to see if it is shorted between either of
the terminals and case. If it is shorted, replace the capacitor.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
DHIGH VOLTAGE CAPACITOR TEST
E CAVITY TEMPERATURE FUSE TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Acontinuitycheckacrossthecavitytemperaturefuseterminalsshouldindicateaclosedcircuitunless
thetemperatureofthe cavitytemperaturefusereachesapproximately302˚F(150˚C). Anopen cavity
temperaturefuseindicatesoverheatingoftheoven,exchangethe cavitytemperaturefuseandcheck
inside of oven cavity and for improper setting of cooking time or operation of control unit. Check for
restricted air flow through the vent holes of the oven cavity, especially the cooling fan and air guide.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
MAGNETRON TEMPERATURE FUSE TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge the high voltage capacitor.
4. Acontinuity checkacross themagnetron temperaturefuse terminalsshould indicatea closedcircuit
unlessthetemperatureofthemagnetrontemperaturefusereachesapproximately302˚F(150˚C).An
open magnetron temperature fuse indicates overheating of the magnetron. Check for restricted air
flow to the magnetron, especially the cooling fan air guide.
C HIGH VOLTAGE RECTIFIER TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Isolate the rectifier from the circuit. Using the highest ohm scale of the meter, read the resistance
across the terminals and observe, reverse the leads to the rectifier terminals and observe meter
reading. If a short is indicated in both directions, or if an infinite resistance is read in both directions,
the rectifier is probably defective and should be replaced.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
NOTE:Besureto use an ohmmeter that will supplya forward biasvoltage of morethan 6.3 volts.
(HIGHVOLTAGESARE PRESENTATTHEHIGHVOLTAGE TERMINAL,SODONOT ATTEMPTTO
MEASURE THE FILAMENT AND HIGH VOLTAGE.)

14
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TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Before performing this test, make sure that the secondary interlock switch and the primary interlock
relayareoperatingproperly,accordingtotheaboveSwitchTestProcedure.Disconnectthewirelead
fromthe monitorswitch (COM)terminal. Checkthe monitorswitch operation by using theohmmeter
asfollows.Whenthedoorisopen,themetershouldindicateaclosedcircuit.Whenthemonitorswitch
actuatoris pushedby a screwdriver throughthe lowerlatch holeon thefront plateof the ovencavity
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
CAUTION: IF THE TEMPERATURE FUSE INDICATES AN OPEN CIRCUIT AT ROOM TEMPERA-
TURE, REPLACE TEMPERATURE FUSE.
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Isolatetheswitchandconnecttheohmmetertothecommon(COM.)andnormallyopen(NO)terminal
of the switch. The meter should indicate an open circuit with the door open and a closed circuit with
the door closed. If improper operation is indicated, replace the secondary interlock switch.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
PRIMARY INTERLOCK SYSTEM TEST
DOOR SENSING SWITCH
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Isolatetheswitchandconnecttheohmmetertothecommon(COM.)andnormallyopen(NO)terminal
of the switch. The meter should indicate an open circuit with the door open and a closed circuit with
the door closed. If improper operation is indicated, replace the door sensing switch.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
NOTE: If the door sensing switch contacts fail in the open position and the door is closed, the cooling
fan, turntable and oven light will be activated by RY1.
PRIMARY INTERLOCK RELAY (RY2)
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect two (2) wire leads from the male tab terminals of the Primary Interlock Relay. Check the
stateoftherelaycontactsusingaohmmeter.Therelaycontactsshouldbeopen.Iftherelaycontacts
are closed, replace the circuit board entirely or the relay itself.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
F SECONDARY INTERLOCK SWITCH TEST
GMONITOR SWITCH TEST

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H BLOWN MONITOR FUSE TEST
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. If the monitor fuse is blown when the door is opened, check the primary interlock relay, secondary
interlockswitchandmonitorswitchaccordingtothe"TESTPROCEDURE"forthoseswitchesbefore
replacing the blown monitor fuse.
CAUTION: BEFORE REPLACING A BLOWN MONITOR FUSE, TEST THE PRIMARY INTERLOCK
RELAY,SECONDARYINTERLOCKSWITCH,DOORSENSINGSWITCHANDMONITOR
SWITCH FOR PROPER OPERATION.
If the monitor fuse is blown by improper switch operation, the monitor fuse and monitor switch must
be replaced with "monitor fuse and monitor switch assembly" part number FFS-BA016/KIT, even if
the monitor switch operates normally. The monitor fuse and monitor switch assembly is comprised
of a 20 ampere fuse and switch.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore,
unlike conventional microwave ovens, proper maintenance cannot be performed with only a voltmeter
and ohmmeter.
In this service manual, the touch control panel assembly is divided into two units, Control Unit and Key
Unit. Also the Control Unit is divided into two units, LSI Unit and Power Unit. Troubleshooting by unit
replacement is described according to the symptoms indicated.
Before testing,
1) Disconnect the power supply cord, and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Disconnect the leads to the primary of the power transformer.
5) Ensure that these leads remain isolated from other components and oven chassis by using
insulation tape.
1. Key Unit.
NOTE ;
1) Check Key unit ribbon connection before replacement.
2) Reconnect all leads removed from components during testing.
3) Re-install the outer case (cabinet).
I TOUCH CONTROL PANEL ASSEMBLY TEST
withthedooropened(inthisconditiontheplungerofthemonitorswitchispushedin),themetershould
indicate an open circuit. If improper operation is indicated, the switch may be defective. After testing
the monitor switch, reconnect the wire lead to the monitor switch (COM) terminal and check the
continuity of the monitor circuit.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply
cord after the outer case is
installed.
8. Run the oven and check all
functions.
Monitor
Switch
Secondary Interlock Switch
Screw Driver
Ohmmeter
RED WHT/WHT

16
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4) Reconnect the power supply cord after the outer case is installed.
5) Run the oven and check all functions.
The following symptoms indicate a defective key unit.
a) When touching the pads, a certain pad produces no signal at all.
b) When touching a number pad, two figures or more are displayed.
c) When touching the pads, sometimes a pad produces no signal.
If the Key unit is defective.
1) Disconnect the power supply cord, and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Replace the Key unit.
5) Reconnect all leads removed from components during testing.
6) Re-install the outer case (cabinet).
7) Reconnect the power supply cord after the outer case is installed.
8) Run the oven and check all functions.
2. Control Unit
The following symptoms indicate a defective control unit. Before replacing the control unit, perform
the Key unit test (Procedure J) to determine if control unit is faulty.
2-1 In connection with pads.
a) When touching the pads, a certain group of pads do not produce a signal.
b) When touching the pads, no pads produce a signal.
2-2 In connection with indicators
a) At a certain digit, all or some segments do not light up.
b) At a certain digit, brightness is low.
c) Only one indicator does not light.
d) The corresponding segments of all digits do not light up; or they continue to light up.
e) Wrong figure appears.
f) A certain group of indicators do not light up.
g) The figure of all digits flicker.
h) The following symptoms indicate a defective LSI unit.
• When touching the keys on the touch screen, a certain key produces no signal at all.
• When touching a number key on the touch screen, two figures or more are displayed.
• When touching the keys on the touch screen, sometimes a key produces no signal.
2-3 Other possible problems caused by defective control unit.
a) Buzzer does not sound or continues to sound.
b) Clock does not operate properly.
c) Cooking is not possible.
When testing is completed,
1) Disconnect the power supply cord, and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Reconnect all leads removed from components during testing.
5) Re-install the outer case (cabinet).
6) Reconnect the power supply cord after the outer case is installed.
7) Run the oven and check all functions.
J KEY UNIT TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. If the display fails to clear when the STOP/CLEAR pad is depressed, first verify the flat ribbon cable
ismakinggoodcontact,verifythatthedoorsensingswitch(stopswitch)operatesproperly;thatisthe
contacts are closed when the door is closed and open when the door is open. If the door sensing
switch (stop switch) is good, disconnect the flat ribbon cable that connects the key unit to the control
unitand makesure thedoorsensing switchis closed(either closethe doororshort thedoor sensing
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST

17
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TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
switch connector). Use the Key unit matrix indicated on the control panel schematic and place a
jumperwirebetween thepinsthat correspondtotheSTOP/CLEAR padmakingmomentary contact.
If the control unit responds by clearing with a beep the key unit is faulty and must be replaced. If the
control unit does not respond, it is faulty and must be replaced. If a specific pad does not respond,
the above method may be used (after clearing the control unit) to determine if the control unit or key
pad is at fault.
5. Reconnect all leads removed from components
during testing.
6. Re-install the outer case (cabinet).
7. Reconnect the power supply cord after the outer
case is installed.
8. Run the oven and check all functions.
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the leads to the primary of the power transformer.
5. Ensurethattheseleadsremainisolatedfromothercomponentsandovenchassisbyusinginsulation
tape.
6. After that procedure, re-connect the power supply cord.
7. Remove the outer case and check voltage between Pin No. 1 of the 2 pin connector (A) and the
common terminal of the relay RY1 on the control unit with an A.C. voltmeter.
The meter should indicate 120 volts, if not check oven circuit.
RY1 and RY2 Relay Test
These relays are operated by D.C. voltage
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation.
DC. voltage indicated ......................Defective relay.
DC. voltage not indicated ................Check diode which is connected to the relay coil. If diode
is good, control unit is defective.
RELAY SYMBOL OPERATIONAL VOLTAGE CONNECTED COMPONENTS
RY1 Approx. 24.8V D.C. Oven lamp / Turntable motor / Cooling fan motor
RY2 Approx. 23.9V D.C. Power transformer
8. Disconnect the power supply cord, and then remove outer case.
9. Open the door and block it open.
10. Discharge high voltage capacitor.
11. Reconnect all leads removed from components during testing.
12. Re-install the outer case (cabinet).
13. Reconnect the power supply cord after the outer case is installed.
14. Run the oven and check all functions.
KRELAY TEST
WARNING : The oven should be fully assembled before following procedure.
(1) Place one cup of water in the center of the turntable tray in the oven cavity.
(2) Close the door, touch the Defrost pad and select compu Defrost. Then select Steaks/Chops/Fish.
LCOMPU DEFROST TEST
Set Up
Pasta
Grains
Beverage
Center
Frozen
Food START
Vegetables
MINUTE
PLUS
Defrost
3+6
More from
Your
Microwave
Baked
Potatoes Reheat
Poultry Fish /
Seafood
Meat
Popcorn
STOP
CLEAR
G 1
G 5
G 6
G13
G12
G11
G15
G 2 G 3 G14

18
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To protect the electronic circuits, this model is provided with a fine foil pattern added to the primary on
the PWB, this foil pattern acts as a fuse.
1. Foil pattern check and repairs.
1) Disconnect the power supply cord, and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Follow the troubleshooting guide given below for repair.
STEPS OCCURRENCE CAUSE OR CORRECTION
1 Only pattern at "a" is broken. *Insert jumper wire J1 and solder.
2 Pattern at "a" and "b" are broken. *Insert the coil RCILF2003YAZZ between "c" and "d".
5) Makeavisual inspectionofthe varistor.
Check for burn damage and examine
the transformer with a tester for the
presence of layer short-circuit (check
the primary coil resistance which is
approximately 133Ω±10%). If any
abnormalconditionisdetected,replace
the defective parts.
6) Reconnect all leads removed from components during testing.
7) Re-install the outer case (cabinet).
8) Reconnect the power supply cord after the outer case is installed.
9) Run the oven and check all functions.
2. Follow the troubleshooting guide given below, if indicator does not light up after above check and
repairs are finished.
1) Disconnect the power supply cord, and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Disconnect the leads to the primary of the power transformer.
5) Ensure that these leads remain isolated from other components and oven chassis by using
insulation tape.
6) After that procedure, reconnect the power supply cord.
7) Follow the troubleshooting guide given below for repair.
STEPS OCCURRENCE CAUSE OR CORRECTION
The rated AC voltage is not present between
1 Pin No. 1 of the 2-pin connector (A) and the Check supply voltage and oven power cord.
common terminal of the relay RY1.
2The rated AC voltage is present at primary Low voltage transformer or secondary circuit defective.
side of low voltage transformer. Check and repair.
8) Disconnect the power supply cord, and then remove outer case.
9) Open the door and block it open.
M FOIL PATTERN ON THE PRINTED WIRING BOARD TEST
(Now, weight 0.5lb is set.) And then touch the start pad.
(3) The oven is in Compu Defrost cooking condition.
(4) The oven will operate as follows
WEIGHT 1ST STAGE 2ND STAGE
LEVEL TIME LEVEL TIME
0.5lb 70% 30sec. 40% 15sec.
(5) If improper operation is indicated, the control unit is probably defective and should be checked.
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
(J1)
VRS1
RY1
a
bd
c