Sharp Carousel R-1211 User manual

35
R-1210
R-1211
In the interest of user-safety the oven should be restored to its
originalconditionandonlypartsidenticaltothosespecifiedshould
be used.
WARNING TO SERVICE PERSONNEL: Microwave ovens con-
tain circuitry capable of producing very high voltage and
current. Contact with the following parts may result in a
severe, possibly fatal, electrical shock. (High Voltage Capaci-
tor, High Voltage Power Transformer, Magnetron, High Volt-
age Rectifier 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
CONTROL PANEL.................................................................................................................................................4
OPERATION..........................................................................................................................................................5
TROUBLESHOOTING GUIDE ..............................................................................................................................7
TEST PROCEDURE ..............................................................................................................................................8
TOUCH CONTROL PANEL ASSEMBLY ............................................................................................................14
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ................................................................20
PICTORIAL DIAGRAM ........................................................................................................................................24
POWER UNIT CIRCUIT ......................................................................................................................................25
LSI UNIT CIRCUIT...............................................................................................................................................26
PRINTED WIRING BOARD .................................................................................................................................27
PARTS LIST ........................................................................................................................................................28
PACKING AND ACCESSORIES .........................................................................................................................33
S2203R1510X//
R-1210
R-1211
OVER THE COUNTER
MICROWAVE OVEN
MODELS
SERVICE MANUAL
SHARP CORPORATION This document has been published to be used for after
sales service only.
The contents are subject to change without notice.
ThisisasupplementalServiceManualforModelsR-1210andR-1211.Thesemodelsarequitesimilartobasemodel
R-1200 and R-1201. Use this supplemental manual together with the Base Models Service Manual (Reference No.
is SY130R1200X//) for complete operation, service information, etc..
SENSOR

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R-1210
R-1211
PRECAUTIONS TO BE OBSERVED BEFORE AND
DURING SERVICING TO AVOID POSSIBLE EXPO-
SURE 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
microwavesource,andmakerepairsasnecessary:(1)interlockoperation,(2)properdoorclosing,(3)seal
andsealingsurfaces(arcing,wear,andotherdamage), (4)damagetoorloosening ofhingesandlatches,
(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
andtransmissionsystemsshallberepaired,replaced,oradjustedbyproceduresdescribedinthismanual
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.
Service personnel should inform SHARP ELECTRONICS CORPORATION of any certified unit
found 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.

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R-1210
R-1211
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 (thatis theconnectinglead ofthe high-
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 these 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. Reconnectthepowersupplycord afterthe outercase is
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. Reconnectthepowersupplycord afterthe outercase is
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.Whenthe 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 microwave leakage test should be carried out.
Don't Touch !
Danger High Voltage

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R-1211
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
bya purchaser,andthereafter (throughtheuseful lifeoftheoven), 5mW/cm2atanypoint 5cmormorefrom theexternal
surface of the oven.
2) Safety interlock switches: Primary interlock switch shall prevent microwave radiation emission in excess of the
requirement as above mentioned, secondary interlock relay and door sensing 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:
Surveyinstruments thatcomply withtherequirementforinstrumentationasprescribedbytheperformancestandard
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.
Theplacingof thisstandard loadin theoven isimportantnot onlyto protectthe oven,but alsotoinsure thatany leakage
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,
andthattheprimaryinterlockswitchandthesecondaryinterlock relaydo turnthe ovenOFF beforeanydoormovement.
NOTE: After servicing, record data on service invoice and microwave leakage report.

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R-1211
SHARP ELECTRONICS CORPORATION
SHARP PLAZA, MAHWAH,
NEW JERSEY 07430-2135
SERVICE MANUAL
OVER THE COUNTER
MICROWAVE OVEN
R-1210/ R-1211
FOREWORD
This Manual has been prepared to provide Sharp Electronics Corp. Service Personnel with Operation and Service
Information for the SHARP OVER THE COUNTER MICROWAVE OVEN, R-1210 and R-1211.
The models R-1210 and R-1211 are quite similar to base models R-1200 and R-1201 (Reference No. is SY130R1200X//).
It is recommended that service personnel carefully study the entire text of this manual and base model service 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 not any other visible damage with the oven.
Servicing and repair work must be carried out only by trained service personnel.
DANGER
Certain initial parts are intentionally not grounded and present a risk of electrical shock only during servicing.
Service personnel - Do not contact the following parts while the appliance is energized;
High Voltage Capacitor, Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage
Harness;
If provided, Vent Hood, Fan assembly, Cooling Fan Motor.
All the parts marked “*” on parts list are used at voltages more than 250V.
Removal of the outer wrap gives access to voltage above 250V.
Allthepartsmarked“∆”onpartslistmaycauseunduemicrowaveexposure,bythemselves,orwhentheyaredamaged,
loosened or removed.

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R-1211
NOTE: Some one-touch cooking features such as "MINUTE PLUS" are disabled after three minutes when the oven
isnot used.These features areautomatically enabledwhenthedooris openedand closedor STOP/CLEAR
button is pressed.
CONTROL PANEL
ITEM DESCRIPTION
Power Requirements 120 Volts / 14.1 Amperes
60 Hertz
Single phase, 3 wire grounded
Power Output 1100 watts (IEC TEST PROCEDURE)
Operating frequency of 2450MHz
Case Dimensions Width 23-7/8"
Height 14-1/16"
Depth 15- 9/16"
Cooking Cavity Dimensions Width 17-1/2"
Height 9-7/8"
1.5 Cubic Feet Depth 14-15/16"
Hood lamp 2 bulbs, 20W x 2, Incandescent light bulbs
Control Complement Touch Control System
Clock ( 1:00 - 12:59 )
Timer (0 - 99 min. 99 seconds)
Microwave Power for Variable Cooking
Repetition Rate;
HIGH................................................Full power throughout the cooking time
P-90 .................................................................... approx. 90% of Full Power
P-80 .................................................................... approx. 80% of Full Power
P-70 .................................................................... approx. 70% of Full Power
P-60 .................................................................... approx. 60% of Full Power
P-50 .................................................................... approx. 50% of Full Power
P-40 .................................................................... approx. 40% of Full Power
P-30 .................................................................... approx. 30% of Full Power
P-20 .................................................................... approx. 20% of Full Power
P-10 .................................................................... approx. 10% of Full Power
P-0 .................................................... No power throughout the cooking time
CUSTOM HELP pad, KEEP WARM PLUS pad
ACCENT LIGHT pad, TASK LIGHT pad, REHEAT pads
SENSOR COOK CENTER pad DEFROST CENTER pad
INSTANT SENSOR pads, Number selection pads
POWER LEVEL pad, TIMER / CLOCK pad
STOP/CLEAR pad, START/MINUTE PLUS pad
Oven Cavity Light 20W x 1 Incandescent light bulb
Safety Standard UL Listed FCC Authorized
DHHS Rules, CFR, Title 21, Chapter 1, Subchapter J
Weight Approx. 50 lbs.
PRODUCT SPECIFICATION
1100
WATTS
KEEP
WARM PLUS
CUSTOM
HELP
ACCENT
LIGHT TASK LIGHT
FRESH ROLLS/
MUFFINS FROZEN ROLLS/ MUFFINS
REHEAT
SENSOR
COOK CENTER
POPCORN SENSOR
REHEAT
BEVERAGE DEFROST
CENTER
HOT
WATER BAKED POTATOES FRESH
VEGETABLES
TIMER
CLOCK
POWER
LEVEL
START
MINUTE PLUS
STOP
CLEAR
12345
67890
COOK SENSOR LBS DEF HELP

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OPERATION
DESCRIPTION OF OPERATING SEQUENCE
Thefollowingisadescriptionofcomponentfunctionsduring
oven operation.
OFF CONDITION
Closing the door activates the door sensing switch and
primary 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).
1. The display will show "SHARP SIMPLY THE BEST
PRESS CLEAR AND PRESS CLOCK".
Toset anyprogram orset theclock, youmust firsttouch
the STOP/CLEAR button. The display will clear, and " :
" will appear .
POWER LEVEL P-0 TO P-90 COOKING
When Variable Cooking Power is programmed, the 120
voltsA.C.issuppliedtothepowertransformerintermittently
throughthecontactsofrelay(RY2)whichisoperatedbythe
control unit within an interval second time base.
Microwave power operation is as follows:
VARI-MODE ON TIME OFF TIME
HIGH (100% power) 32 sec. 0 sec.
P-90 (approx. 90% power) 30 sec. 2 sec.
P-80 (approx. 80% power) 26 sec. 6 sec.
P-70 (approx. 70% power) 24 sec. 8 sec.
P-60 (approx. 60% power) 22 sec. 10 sec.
P-50 (approx. 50% power) 18 sec. 14 sec.
P-40 (approx. 40% power) 16 sec. 16 sec.
P-30 (approx. 30% power) 12 sec. 20 sec.
P-20 (approx. 20% power) 8 sec. 24 sec.
P-10 (approx. 10% power) 6 sec. 26 sec.
P-0 (0% power) 0 sec. 32 sec.
Note: The ON/OFF time ratio does not correspond with
the percentage of microwave power, because
approx. 3 seconds are needed for heating of the
magnetron filament.
SENSOR COOKING CONDITION
Using the Sensor Cooking function, the foods are cooked
without figuring time, power level or quantity. When the oven
senses enough steam from the food, it relays the information
toitsmicroprocessorwhichwillcalculatetheremainingcook-
ing time and power level needed for best results. When the
foodiscooked,watervaporisdeveloped.Thesensor“senses”
the vapor and its resistance increases gradually. When the
resistance reaches the value set according to the menu,
supplementarycookingisstarted.Thetimeofsupplementary
cookingisdeterminedbyexperimentwitheachfoodcategory
and inputted into the LSI.
An example of how sensor works (Baked potatoes):
1. Potatoes at room temperature. Vapor is emitted very
slowly.
2. Heatpotatoes. Moistureand humidityis emittedrapidly.
You can smell the aroma as it cooks.
3. Sensor detects moisture and humidity and calculates
cooking time and variable power.
Cooking Sequence.
1. Operatetheoveninsensorcookingmodebyreferringto
operation manual.
NOTE: TheovenshouldnotbeoperatedonSensorCooking
immediately after plugging in the unit. Wait two
minutes before cooking on Sensor Cooking.
2. The coil of shut-off relay (RY1) is energized, the oven
lamp, turntable motor and cooling fan motor are turned
on, but the power transformer is not turned on.
3. Afterabout16seconds,thecookrelay(RY2)isenergized.
The power transformer is turned on, microwave energy
is produced and first stage is started.
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,thedisplayswitchesoverto theremainingcooking
time and the timer counts down to zero.
At this time, the door may be opened to stir food, turn it
or season, etc.
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
timeofdaywillreappearon thedisplay andthe ovenwill
revert to an OFF condition.
MICROWAVE
MICROWAVE
AH SENSOR

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R-1211
Figure O-2. Oven Schematic-Cooking Condition
Figure O-1. Oven Schematic-Off Condition
NOTE: " " indicates components with potential above 250V. SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. CLOCK APPEARS ON DISPLAY.
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. COOKING TIME PROGRAMMED.
3. VARIABLECOOKINGCONTROL"HIGH".
4. "START" BUTTON PRESSED.
MAGNETRON
TEMPERATURE FUSE
FUSE
20A
TURNTABLE MOTOR
FAN MOTOR
MAGNETRON
OVEN LAMP
MONITOR SWITCH
BLKWHT
POWER
TRANSFORMER
HIGH VOLTAGE
CAPACITOR
1.0µF/ AC2300V
HIGH VOLTAGE
RECTIFIER
COM.
N.O.
COM.
CONTROL UNIT
GND
GRN
A1
A3 A5 N.O.
B2
B1
DOOR
SENSING
SWITCH
PRIMARY
INTERLOCK
SWITCH
120 V AC.
60 Hz
HOOD
LAMP
HL
RY1
RY2
SECONDARY
INTERLOCK
RELAY
OVEN LAMP
RELAY
FM
OL
TTM
RY3
RY4
CAVITY
TEMPERATURE FUSE
HL
F1
F2
F3
AH SENSOR
TURNTABLE MOTOR
FAN MOTOR
MAGNETRON
OVEN LAMP
MONITOR SWITCH
POWER
TRANSFORMER
HIGH VOLTAGE
RECTIFIER
COM.
N.O.
COM.
CONTROL UNIT
N.O.
B2
B1
DOOR
SENSING
SWITCH
PRIMARY
INTERLOCK
SWITCH
RY1
RY2
SECONDARY
INTERLOCK
RELAY
OVEN LAMP
RELAY
FM
OL
TTM
MAGNETRON
TEMPERATURE FUSE
FUSE
20A
BLKWHT
HIGH VOLTAGE
CAPACITOR
1.0µF/ AC2300V
GND
GRN
A1
A3 A5
120 V AC.
60 Hz
HOOD
LAMP
HL
RY3
RY4
CAVITY
TEMPERATURE FUSE
HL
F1
F2
F3
AH SENSOR

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R-1211
TROUBLESHOOTING GUIDE
Nevertouch anypart inthecircuitwithyourhandor anuninsulated toolwhilethepowersupplyisconnected.
Whentroubleshootingthe microwaveoven, itis helpfulto followthe Sequenceof Operationinperformingthechecks.Many
ofthepossiblecausesoftroublewillrequirethataspecifictestbeperformed.Thesetestsaregivenaprocedureletterwhich
will be found in the "Test Procedure "section.
IMPORTANT:
If the oven becomes inoperative because of a blown moni-
tor fuse, check the monitor switch, relay (RY1) secondary
interlock relay (RY2), door sensing switch and primary
interlockswitchbeforereplacingthemonitorfuse.If monitor
fuse is replaced, the monitor switch must also be replaced.
Use part FFS-BA016/KiT as an assembly.
IMPORTANT:
Whenever troubleshooting is performed with the power
supplycorddisconnected.Itmayin,somecases,beneces-
sary 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. 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. Reconnectthepowersupplycord afterthe outercase is
installed.
7. Run the oven and check all functions.
JOCK
CONTROL UNIT
AH SENSOR
SHORTED OR OPENED WIRING
The oven stops and "ERROR" is displayed or 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 seconds after starting.
TEST PROCEDURE
PROBLEM
CONDITION
SENSOR
COOKING
CONDITION
POSSIBLE CAUSE
AND
DEFECTIVE PARTS
NOTE: For additional troubleshooting procedures, please refer back to the R-1200/1201 base model Service
Manual.

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R-1211
JTOUCH CONTROL PANEL ASSEMBLY TEST
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
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, and also the Control Unit is divided into two units, LSI Unit and Power Unit,
and troubleshooting by unit replacement is described according to the symptoms indicated.
Before testing,
1) Disconnect the power supply cord, and then remove outer case. Refer to procedure of "
REMOVAL OF OVEN FROM WALL " and " OUTER CASE REMOVAL ".
2) Open the door and block it open.
3) To discharge high voltage capacitor, wait for 60 seconds.
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) Re-install the outer case (cabinet).
3) Reconnect the power supply cord after the outer case is installed.
4) 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, replace the key unit.
2. Control Unit.
The following symptoms indicate a defective control unit. Before replacing the control unit, perform
the Key unit test (Procedure K) 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.
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.
2) Open the door and block it open.
3) To discharge high voltage capacitor, wait for 60 seconds.
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.
KKEY UNIT TEST
1. Disconnect the power supply cord.

9
R-1210
R-1211
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
2. Open the door and block it open.
3. To discharge high voltage capacitor, wait for 60 seconds.
4. If the display fails to clear when the STOP/CLEAR pad is depressed, first verify the flat ribbon cable
ismakinggoodcontact,verifythatthedoorsensingswitchoperatesproperly;thatisthecontactsare
closed when the door is closed and open when the door is open. If the door sensing switch is good,
disconnect the flat ribbon cable that connects the key unit to the control unit and make sure the door
sensing switch is closed (either close the door or short the door sensing switch connecter). Use the
Key unit matrix indicated on the control panel schematic and place a jumper wire between the pins
thatcorrespondtothe STOP/CLEARpadmakingmomentarycontact. Ifthecontrolunitresponds 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.
8. Run the oven and check all functions.
LRELAY TEST
1. Disconnect the power supply cord, and then remove outer case. Refer to procedure of “ REMOVAL
OF OVEN FROM WALL ” and “ OUTER CASE REMOVAL ”.
2. Open the door and block it open.
3. To discharge high voltage capacitor, wait for 60 seconds.
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. Check voltage between normal open terminal of the relay RY2 and the normal open 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, RY2, RY3 and RY4 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. -26.3V D.C. Oven lamp / Fan motor / Turntable motor
RY2(COOK) Approx. -25.3V D.C. Power transformer
RY3 Approx. -26.3V D.C. Hood lamp
RY4 Approx. -26.3V D.C. Hood lamp
8. Disconnect the power supply cord.
9. Open the door and block it open.
G11G12 G 9
G 8
POPCORN
BEVERAGE
SENSOR
REHEAT CUSTOM HELP
FRESH
VEGETABLES
POWER
LEVEL
BAKED
POTATOES
FRESH
ROLLS /
MUFFINS
FROZEN
ROLLS /
MUFFINS
SENSOR
COOK
CENTER
KEEP
WARM
PLUS
TIMER
CLOCK
HOT
WATER DEFROST CENTER TASK LIGHT ACCENT LIGHT
3
8
2
7
1
6
5
0
4
9
G 7 G 6 G 5 G 4 G 3 G 2 G 1
G10
STOP
CLEAR
START
MINUTE PLUS

10
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MDEFROST CENTER TEST
NFOIL PATTERN ON THE PRINTED WIRING BOARD TEST
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
10.To discharge high voltage capacitor, wait for 60 seconds.
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.
(1) Open the door.
(2) Place one cup of water in the center of the turntable tray in the oven cavity.
(3) Close the door.
(4) Touch the “ DEFROST CENTER ” pad. And touch the number pad 2. Then touch the number pad 5.
(5) Touch the “ START ” pad.
(6) The oven is in Defrost center cooking condition.
(7) The oven will operate as follows.
Menu 1ST STAGE 2ND STAGE
Steaks/Chops LEVEL TIME LEVEL TIME
0.5lbs 60% 57sec. 40% 17sec.
(8) If improper operation is indicated, the control unit is probably defective and should be checked.
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.
2) Open the door and block it open.
3) To discharge high voltage capacitor, wait for 60 seconds.
4) Removethepowerunit,referringtotheprocedureof“RIGHTPANELASSEMBLYAND POWER
UNIT REMOVAL ”.
5) 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”.
6) Makeavisualinspectionofthevaristor.Check
for burned damage and examine the
transformer with a tester for the presence of
layer short-circuit (check the primary coil
resistance which is approximately 780Ω±
10%). If any abnormal condition is detected,
replace the defective parts.
7) Reconnect all leads removed from
components during testing.
8) Re-install the power unit to the right panel
and re-install the right panel to the oven.
9) Reconnect the power supply cord.
10) 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. Refer to procedure of “
REMOVAL OF OVEN FROM WALL ” and “ OUTER CASE REMOVAL ”.
RY1 RY2
(J1)
bc
da
T1
13
VRS1

11
R-1210
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TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
2) Open the door and block it open.
3) To discharge high voltage capacitor, wait for 60 seconds.
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, re-connect 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 the normal open terminal of the relay RY2 and Check supply voltage and oven power cord.
the normal open 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.
9) Open the door and block it open.
10) To discharge high voltage capacitor, wait for 60 seconds.
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.
OAH SENSOR TEST
Checking the initial sensor cooking condition
WARNING : The oven should be fully assembled before following procedure.
(1) The oven should be plugged in at least two minutes before sensor cooking.
(2) Room temperature should not exceed 95˚F (35˚C).
(3) The unit should not be installed in any area where heat and steam are generated. The unit should
not be installed, for example, next to a conventional surface unit. Refer to the “INSTALLATION
INSTRUCTIONS” of the operation manual.
(4) Exhaust vents are provided on the back of the unit for proper cooling and air flow in the cavity. To
permit adequate ventilation, be sure to install so as not to block these vents. There should be some
space for air circulation.
(5) Besuretheexteriorofthecookingcontainerandtheinterioroftheovenaredry.Wipeoffanymoisture
with a dry cloth or paper towel.
(6) The Sensor works with food at normal storage temperature. For example, chicken pieces would be
at refrigerator temperature and canned soup at room temperature.
(7) Avoid using aerosol sprays or cleaning solvents near the oven while using Sensor settings. The
sensor will detect the vapor given of by the spray and turn off before food is properly cooked.
(8) If the sensor has not detected the vapor of the food, ERROR will appear and the oven will shut off.
Water load cooking test
WARNING : The oven should be fully assembled before following procedure.
Make sure the oven has been plugged in at least two minutes before checking sensor cook operation.
The cabinet should be installed and screws tightened.
(1) Fill approximately 200 milliliters (7.2 oz) of tap water in a 1000 milliliter measuring cup.
(2) Place the container on the center of tray in the oven cavity.
(3) Close the door.
(4) Touch the TIMER/CLOCK once, the POWER LEVEL pad twice, the START pad once, the number
pad1onceandthenumberpad4once.Now,theovenisinthesensorcookingcondition,and“AH20
”, “ SENSOR ” and “ COOK ” will appear in the display.
(5) The oven will operate for the first 16 seconds, without generating microwave energy.
NOTE: ERROR will appear if the door is opened or STOP/CLEAR pad is touched during first stage of
sensor cooking.

12
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TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
(6) After approximately 16 seconds, microwave energy is produced.
IfERRORisdisplayedortheovendoesnotturnoff,replacetheAHsensororcheckthecontrolunit,refer
toexplanationbelow.Iftheovenstopsafter5minutesandERRORisdisplayed,theAHsensorisnormal.
Check other parts except the AH sensor.
TESTING METHOD FOR AH SENSOR AND/OR CONTROL UNIT
To determine if the sensor is defective, the simplest method is to replace it with a new replacement
sensor.
(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) Remove the AH sensor.
(5) Install the new AH sensor.
(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) Reconnect the oven to the power supply and check the sensor cook operation as follows:
9-1. Fill approximately 200 milliliters (7.2 oz) of tap water in a 1000 milliliter measuring cup.
9-2. Place the container on the center of tray in the oven cavity.
9-3. Close the door.
9-4. Touchthe TIMER/CLOCKpad once,thePOWERLEVEL padtwice, theSTARTpadonce, the
number pad 1 once and the number pad 4 once.
9-5. The control panel is in automatic Sensor operation.
9-6. The oven turns off automatically, and the time for detecting moisture will be displayed.
If new sensor dose not operate properly, the problem is with the control unit, and refer to explanation
below.
CHECKING CONTROL UNIT
(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 sensor connector that is mounted to control panel.
(5) Then connect the dummy resistor circuit (see fig.) to the sensor connector of control panel.
(6) Disconnect the leads to the primary of the power transformer.
(7) Ensurethattheseleadsremainisolatedfromothercomponentsandovenchassisbyusinginsulation
tape.
(8) After that procedure, re-connect the power supply cord.
(9) Check the sensor cook operation proceed as follows:
9-1. Touch the TIMER/CLOCK pad once, the POWER LEVEL pad twice, the START pad once and
the number pad 1 once and the number pad 4 once.
9-2. The control panel is in the sensor cooking operation.
9-3. After approximately 19 seconds, push plunger of select switch for more than 3 seconds. This
condition is same as judgement by AH sensor.
9-4. After approximately 3 seconds, the display shows “ X X . X X ” which is the time for detecting
moisture.
If the above is not the case, the control unit is probably defective.
If the above is proper, the AH sensor is probably defective.
(10) Disconnect the power supply cord, and then remove outer case.
(11) Open the door and block it open.
(12) Discharge high voltage capacitor.
(13) Disconnect the dummy resistor circuit from the sensor connector of control panel.
(14) Carry out necessary repair.
(15) Reconnect all leads removed from components during testing and repairing.
(16) Re-install the outer case (cabinet).

13
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TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
(17) Reconnect the power supply cord after the outer case is installed. Run the oven and check all
functions.
(18) Carry out “Water load cooking test” again and ensure that the oven works properly.
R1, R2 : 22Ω±1% 1/2W
R3 : 4.3kΩ±5% 1/4W
R4 : 1MΩ±5% 1/4W
Sensor Dummy Resistor Circuit
Plunger
NC
NO
COM
COM NO
NC
R3 R4
R1
R2
1
2
3
F-1
F-2
F-3
To connector (F)
on Control Unit.
CONNECTOR

14
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TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOUCH CONTROL PANEL
3) Synchronizing Signal Circuit
The power source synchronizing signal is available in
order to compose a basic standard time in the clock
circuit.Itincorporatesaverysmallerrorbecauseitworks
on commercial frequency.
4) Reset Circuit
A circuit to generate a signals which resetting the LSI to
the initial state when power is applied.
5) Buzzer Circuit
The buzzer is responds to signals from the LSI to emit
audiblesounds(keytouchsoundandcompletionsound).
6) Door Sensing Switch
A switch to inform the LSI if the door is open or closed.
7) Relay Circuit
To drive the magnetron, fan motor, turntable motor and
light the oven lamp and hood lamp.
8) Indicator Circuit
This circuit consists of 25 segments and 4 common
electrodes using a Light Crystal Display.
9) Back Light Circuit
A circuit to drive the back light (Light emitting diodes
LD1-LD4).
10) Absolute Humidity Sensor Circuit
Thiscircuit detectsmoistureofthecooking foodto allow
its automatic cooking.
The touch control section consists of the following units
as shown in the touch control panel circuit.
(1) Key Unit
(2) Control Unit (The Control unit consists of LSI Unit and
Power U nit)
The principal functions of these units and the signals com-
municated among them are explained below.
Key Unit
The key unit is composed of a matrix, signals generated in
theLSIaresenttothekeyunitthroughP20,P21,P22, P23,
P24, P25, P26 and P27.
When a key pad is touched, a signal is completed through
the key unit and passed back to the LSI through P43, P44,
P45 and P46 to perform the function that was requested.
Control Unit
Control unit consists of LSI, power source circuit, synchro-
nizingsignal circuit,reset circuit,buzzercircuit,relaycircuit
indicator circuit, back light circuit and absolute humidity
sensor circuit.
1) LSI
This LSI controls the key strobe signal, relay driving
signal for oven function and indicator signal.
2) Power Source Circuit
Thiscircuitgeneratesvoltagesnecessaryforthecontrol
unit from the AC line voltage.
Inaddition, thesynchronizingsignal isavailablein order
to compose a basic standard time in the clock circuit.
Symbol Voltage Application
VC -5.3V LSI(IC1)

15
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DESCRIPTION OF LSI
LSI
The I/O signal of the LSI is detailed in the following table.
Pin No. Signal I/O Description
1-2 VL2-VL1 IN Power source voltage input terminal.
Standard voltage for LCD.
3-6 AN7-AN4 IN Terminal to change cooking input according to the Model.
By using the A/D converter contained in the LSI, DC voltage in accordance with the
Model in operation is applied to set up its cooking constant.
7 AN3 OUT Back light circuit (Light emitting diodes) driving signal.
8 AN2 IN To input signal which communicates the door open/close information to LSI.
Door close “H” level signal (0V). Door open “L” level signal (-5V).
9 AN1 IN AH sensor input..
This input is an analog input terminal from the AH sensor circuit, and connected to the
A/D converter built into the LSI.
10 AN0 IN Used for initial balancing of the bridge circuit (absolute humidity sensor). This input is
ananaloginputterminalfromtheAHsensorcircuit,andconnectedtotheA/Dconverter
built into the LSI.
11-13 P57-P55 OUT Used for initial balancing of the bridge circuit (absolute humidity sensor).
14 CNTR0 OUT Signal to sound buzzer (2.0 kHz).
A: key touch sound.
B: Completion sound.
15 P53 OUT Used for initial balancing of the bridge circuit (absolute humidity sensor).
16 P52 OUT Oven lamp, fan motor and turntable motor driving signal
To turn on and off shut off relay (RY1). The
squarewaveformvoltageisdeliveredtothe
RY1 driving circuit and RY2 control circuit.
17 P51 OUT Used for initial balancing of the bridge circuit (absolute humidity sensor).
18 P50 OUT Terminal not used.
19 P47 OUT Magnetron high-voltage circuit driving signal.
Toturnonandoffthecookrelay(RY2). The
signals holds “L” level during microwave
cooking and “H” level while not cooking. In
othercookingmodes(variable cooking)the
signal turns to “H” level and “L” level in
repetition according to the power level.
20 P46 IN Signal coming from touch key.
Wheneither G12line onkey matrixis touched,a correspondingsignal outof P20- P27
will be input into P46. When no key is touched, the signal is held at “H” level.
21 P45 IN Signal similar to P46.
WheneitherG11lineonkeymatrixistouched,acorrespondingsignalwillbeinputintoP45.
22 P44 IN Signal similar to P46.
WheneitherG10lineonkeymatrixistouched,acorrespondingsignalwillbeinputintoP44.
23 P43 IN Signal similar to P46.
WheneitherG9lineonkeymatrixistouched,acorrespondingsignalwillbeinputintoP43.
24 INT0 IN Signal synchronized with commercial power source frequency.
This is the basic timing for time processing of LSI.
A
B
0.1 sec.
2.0 sec.
H : GND
L : -5V
H : GND
L : -5V
16.7 msec.
During cooking
H : GND
L : -5V
Maximum
output
70% of maximum
output
H : GND
L : -5V
H : GND
L : -5V
ON
ON
OFF
OFF OFF
24 sec.
8 sec.
16.7 msec.
H : GND
L : -5V

16
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25 P41 OUT Terminal not used.
26 P40 IN Connected to GND through the pull-down resistor R100.
27 RESET IN Auto clear terminal.
Signal is input to reset the LSI to the initial state when power is applied.
28-29 P71-P70 OUT Terminal not used.
30 XIN IN Internal clock oscillation frequency input setting.
The internal clock frequency is set by inserting the ceramic filter oscillation circuit with
respect to XOUT terminal.
31 XOUT OUT Internal clock oscillation frequency control output.
Output to control oscillation input of XIN.
32 VSS IN Power source voltage: -5.0V.
VC voltage of power source circuit input.
33 P27 OUT Key strobe signal.
Signalappliedtotouch-keysection.ApulsesignalisinputtoP43-P46terminalwhileone
of G8 line keys on key matrix is touched.
34 P26 OUT Key strobe signal.
Signalappliedtotouch-keysection.ApulsesignalisinputtoP43-P46terminalwhileone
of G7 line keys on key matrix is touched.
35 P25 OUT Key strobe signal.
Signalappliedtotouch-keysection.ApulsesignalisinputtoP43-P46terminalwhileone
of G6 line keys on key matrix is touched.
36 P24 OUT Key strobe signal.
Signalappliedtotouch-keysection.ApulsesignalisinputtoP43-P46terminalwhileone
of G5 line keys on key matrix is touched.
37 P23 OUT Key strobe signal.
Signalappliedtotouch-keysection.ApulsesignalisinputtoP43-P46terminalwhileone
of G4 line keys on key matrix is touched.
38 P22 OUT Key strobe signal.
Signalappliedtotouch-keysection.ApulsesignalisinputtoP43-P46terminalwhileone
of G3 line keys on key matrix is touched.
39 P21 OUT Key strobe signal.
Signalappliedtotouch-keysection.ApulsesignalisinputtoP43-P46terminalwhileone
of G2 line keys on key matrix is touched.
40 P20 OUT Key strobe signal.
Signalappliedtotouch-keysection.ApulsesignalisinputtoP43-P46terminalwhileone
of G1 line keys on key matrix is touched.
41 P17 OUT Hood lamp driving signal.
To turn on and off relay(RY6). “L” level: During
Hood lamp ON. “H” level: During Hood lamp OFF.
42 P16 OUT Hood lamp driving signal.
To turn on and off relay(RY5). “L” level: During
Hood lamp ON. “H” level: During Hood lamp OFF.
43 P15 OUT Hood motor high / low driving signal.
Toturnon andoffrelay(RY3).“L”level:DuringHood
motor high. “H” level: During Hood motor low.
44 P14 OUT Hood motor driving signal.
To turn on and off relay(RY4). “L” level: During
HoodmotorON.“H”level:DuringHoodmotorOFF.
45-47 P13-P11 OUT Terminal not used.
Pin No. Signal I/O Description

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48-72 SEG24-SEG0 OUT Segment data signal.
Connected to LCD.
The relation between signals are as follows:
LSI signal (Pin No.) LCD (Pin No.) LSI signal (Pin No.) LCD (Pin No.)
SEG 24 (48) ---------------- SEG24 (29) SEG 11 (61) ------------------ SEG11 (16)
SEG 23 (49) ---------------- SEG23 (28) SEG 10 (62) ------------------ SEG10 (15)
SEG 22 (50) ---------------- SEG22 (27) SEG 9 (63) ------------------ SEG 9 (14)
SEG 21 (51) ---------------- SEG21 (26) SEG 8 (64) ------------------ SEG 8 (13)
SEG 20 (52) ---------------- SEG20 (25) SEG 7 (65) ------------------ SEG 7 (12)
SEG 19 (53) ---------------- SEG19 (24) SEG 6 (66) ------------------ SEG 6 (11)
SEG 18 (54) ---------------- SEG18 (23) SEG 5 (67) ------------------ SEG 5 (10)
SEG 17 (55) ---------------- SEG17 (22) SEG 4 (68) ------------------ SEG 4 ( 9)
SEG 16 (56) ---------------- SEG16 (21) SEG 3 (69) ------------------ SEG 3 ( 8)
SEG 15 (57) ---------------- SEG15 (20) SEG 2 (70) ------------------ SEG 2 ( 7)
SEG 14 (58) ---------------- SEG14 (19) SEG 1 (71) ------------------ SEG 1 ( 6)
SEG 13 (59) ---------------- SEG13 (18) SEG 0 (72) ------------------ SEG 0 ( 5)
SEG 12 (60) ---------------- SEG12 (17)
73/74 VCC/VREF IN Connected to GND.
75 AVSS IN Connected to VC.
76 COM3 OUT Common data signal. Connected to LCD signal COM4.
77 COM2 OUT Common data signal. Connected to LCD signal COM3.
78 COM1 OUT Common data signal. Connected to LCD signal COM2.
79 COM0 OUT Common data signal. Connected to LCD signal COM1.
80 VL3 IN Power source voltage input terminal.
Standard voltage for LCD.
Pin No. Signal I/O Description

18
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ABSOLUTE HUMIDITY SENSOR CIRCUIT
(1) Structure of Absolute Humidity Sensor
The absolute humidity sensor includes two thermistors
asshown intheillustration.One thermistoris housedin
the closed vessel filled with dry air while another in the
openvessel.Eachsensorisprovidedwiththeprotective
cover made of metal mesh to be protected from the
external airflow.
(2) Operational Principle of Absolute Humidity Sensor
Thefigurebelowshowsthebasicstructureofanabsolute
humidity sensor. A bridge circuit is formed by two
thermistors and two resistors (R1 and R2).
The output of the bridge circuit is to be amplified by the
operational amplifier.
Each thermistor is supplied with a current to keep it
heated at about 150˚C (302˚F), the resultant heat is
dissipatedintheairandifthetwothermistorsareplaced
in different humidity conditions they show different
degrees of heat conductivity leading to a potential
differencebetweenthemcausinganoutputvoltagefrom
the bridge circuit, the intensity of which is increased as
the absolute humidity of the air increases. Since the
output is very minute, it is amplified by the operational
amplifier.
(3) DetectorCircuitofAbsoluteHumiditySensorCircuit
Thisdetectorcircuitisusedtodetecttheoutputvoltage
oftheabsolutehumiditycircuittoallowtheLSItocontrol
sensor cooking of the unit. When the unit is set in the
sensorcookingmode,16secondsclearingcycleoccurs
than the detector circuit starts to function and the LSI
observestheinitialvoltageavailableatitsAN1terminal.
Withthisvoltagegiven,theswitchesSW1toSW5inthe
LSI are turned on in such a way as to change the
resistance values in parallel with R53 ~ R57. Changing
the resistance values results in that there is the same
potential at both F-3 terminal of the absolute humidity
sensorandAN0terminaloftheLSI.The voltageofAN1
terminal will indicate about -2.5V. This initial balancing
is set up about 16 seconds after the unit is put in the
SensorCookingmode.Asthesensorcookingproceeds,
the food is heated to generate moisture by which the
resistance balance the bridge circuit is deviated to
increase the voltage available at AN1 terminal of the
LSI.
ThentheLSIobservesthatvoltageatAN1terminaland
comparesitwithitsinitialvalue,andwhenthecomparison
ratereachesthepresetvalue(fixedforeachmenutobe
cooked),theLSIcausestheunittostopsensorcooking;
thereafter, the unit goes in the next operation
automatically.
When the LSI starts to detect the initial voltage at AN1
terminal 16 seconds after the unit has been put in the
SensorCooking mode,if itisnot possibletobalance, of
the bridge circuit due to disconnection of the absolute
humiditysensor,ERRORwillappearonthedisplayand
the cooking is stopped.
1) Absolute humidity sensor circuit
ventilation opening for sensing Sensing part
(Open vessel) Sensing part
(Closed vessel)
Thermistors
C
S
R3
R1
R2
+
Operational
amplifier Output
voltage
S : Thermistor
open vessel
C : Thermistor
closed vessel
2
Absolute humidity (g/m )
Output voltage
Absolute humidity vs,
output voltage characteristic
SW1
SW2
SW3
SW4
SW5
P57
P56
P55
P51
P53
LSI
(IC1)
AN0
AN1
620k
300k
150k
75k
37.4k
11
17
15
10
9
13
12
47k
47k
IC2 15k
0.01uF
0.1uF
0.01uF
+
VA : -15V VA : -15V
R50
330
C50
C51
C51
C50
S
F-2 1.8k
F-1
F-3C3.57k
3.32k
VC : -5V
0.1
uF
C. Thermistor in
closed vessel
S. Thermistor in
open vessel
R53
R54
R52
R51
360k
R54
R53
R50 R51
D50
R55
R56
R57
R52