Sharp R-419CK User manual

R-419CK
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, contact with following parts may result in a severe,
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 ................................................................................................................................. 5
OPERATION ........................................................................................................................................................ 6
TEST PROCEDURE ............................................................................................................................................ 8
PICTORIAL DIAGRAM....................................................................................................................................... 11
LSI UNIT CIRCUIT ............................................................................................................................................. 12
PARTS LIST....................................................................................................................................................... 13
PACKING AND ACCESSORIES ........................................................................................................................ 17
S100M140R419E
R-419CK
MICROWAVE OVEN
MODEL
SUPPLEMENTAL SERVICE MANUAL
SHARP ELECTRONCS CORPORATION This document has been published to be used for after
sales service only.
The contents are subject to change without notice.
Service Headquarters: Sharp Plaza, Mahwah, New Jersey, 07430-2135
R-419CK
This is a supplemental Service Manual for Microwave Oven model R-419CK. This model is quite similar to the base
model R-420CK (S/M# S49M132R420CE).
This supplemental manual must be used in conjunction with the base model service manual for complete operation,
service, safety and replacement parts information.

R-419CK
PRECAUTIONSTO BE OBSERVED BEFORE AND
DURING SERVICING TO AVOID POSSIBLE
EXPOSURE TO EXCESSIVE MICROWAVE
ENERGY
(a) Do not operate or allow the oven to be operated with the door open.
(b) Make the following safety checks on all ovens to be serviced before activating the magnetron or other
microwave source, and make repairs as necessary: (1) interlock operation, (2) proper door closing, (3)
seal and sealing surfaces (arcing, wear, and other damage), (4) damage to or loosening of hinges and
latches, (5) evidence of dropping or abuse.
(c) Before turning on microwave power for any service test or inspection within the microwave generating
compartments, check the magnetron, wave guide or transmission line, and cavity for proper alignment,
integrity, and connections.
(d) Any defective or misadjusted components in the interlock, monitor, door seal, and microwave
generation and transmission systems shall be repaired, replaced, or adjusted by procedures described
in this manual before the oven is released to the owner.
(e) A microwave leakage check to verify compliance with the Federal Performance Standard should be
performed on each oven prior to release to the owner.
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-419CK
WARNINGTO 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. Disconnect the power supply cord , and then
remove 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 (that isthe connecting leadof the high-
voltage rectifier) against the chassis with the use of an
insulated screwdriver.
Whenever troubleshooting is performed the power supply
mustbedisconnected.Itmayin,somecases,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. Reconnect the 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. Reconnect the 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 two minutes haselapsed (timerat zero)
carefully check that the water is now hot. If the water
remainscoldcarryoutBeforeServicing procedureandre-
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
R-419CK
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,and thereafter (throughtheusefullifeof theoven),5mW/cm2atany point 5cmormorefromthe external
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±5O C (68OF) in the center of the oven cavity.
Thewatercontainershallbea low formof600ml(20oz)beaker with aninsidediameterofapprox.8.5cm (3-1/2 in.)and
made of an electrically nonconductive material such as glass or plastic.
Theplacing ofthis standard load in theoven isimportant notonly toprotect the oven, but alsoto insurethat anyleakage
is measured accurately.
4) Set the cooking control on Full Power Cooking Mode.
5) Closethedoorandselectacookcycleofseveralminutes.Ifthewaterbeginstoboilbeforethesurveyiscompleted,replace
it with 275 ml of cool water.
C. Leakage test:
Closed-door leakage test (microwave measurement)
1) Grasptheprobeofthesurveyinstrumentandholditperpendiculartothegapbetweenthedoorandthebodyoftheoven.
2) Movetheprobeslowly,notfasterthan 1in./sec.(2.5cm/sec.)alongthegap,watchingforthemaximumindicationonthe
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-419CK
SHARP ELECTRONICS CORPORATION
SHARP PLAZA, MAHWAH,
NEW JERSEY 07430-2135
SERVICE MANUAL
MICROWAVE OVEN
R-419CK
FOREWORD
This Manual has been prepared to provide Sharp Electronics Corp.
Service Personnel with Operation and Service Information for the
SHARP MICROWAVE OVEN, R-419CK.
Itisrecommendedthatservicepersonnelcarefullystudytheentiretext
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,bythemselves,orwhentheyaredamaged,loosenedor
removed.
PRODUCT DESCRIPTION
GENERAL INFORMATION
OPERATION
TROUBLESHOOTING GUIDE AND
TEST PROCEDURE
WIRING DIAGRAM
PARTS LIST

4
R-419CK
ITEM DESCRIPTION
Power Requirements 120 Volts / 13.3 Amperes/1550Watts
60 Hertz
Single phase, 3 wire grounded
Power Output 1100 watts (IEC-705 TEST PROCEDURE)
Operating frequency of 2450MHz
Case Dimensions Width 21-11/16"
Height 12-3/8"
Depth 17-3/8"
Cooking Cavity Dimensions Width 15"
1.4 Cubic Feet Height 9-7/16"
Depth 16-3/4"
Tray Size 14-1/8" Diameter
ControlComplement Touch Control System
Clock ( 1:00 - 12:59 )
Timer (0 - 99 min. 99 seconds)
Microwave Power for Variable Cooking
Repetition Rate;
P-HI ................................................. 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
BEVERAGE pad
MINUTE PLUS pad, INSTANT ACTION pads
COMPU DEFROST pads, Number selection pads
Power Level pad, Timer/Clock pad
Stop/Clear pad, START 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.
Intheeventofanelectricalshortcircuit,groundingreducestheriskofelectricshockbyprovidinganescapewirefortheelectric
current.
WARNING: Improper use of the grounding plug can result in a risk of electric shock.
ElectricalRequirements
The electrical requirements are a 120 volt 60 Hz, AC only,
15or20amp.fusedelectricalsupply.Itisrecommendedthataseparatecircuitservingonlythisappliancebeprovided.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.
Whereatwo-prongedwall-receptacleisencountered,itisthepersonalresponsibilityandobligationofthecustomertocontact

5
R-419CK
a qualified electrician and have it replaced with a properly grounded
three-pronged wall receptacle or have a grounding adapter properly
groundedandpolarized.Iftheextensioncordmustbeused,itshouldbe
a 3-wire, 15 amp. or higher rated cord. Do not drape over a countertop
ortablewhereitcanbepulledonbychildrenortrippedoveraccidentally.
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. Time display: Digital display, 99
minutes 99 seconds.
10.Coupling.
11.Wave guide cover.
12.Power supply cord
TOUCH CONTROL PANEL
1
65
4
210
11
12
9
7
8
3

6
R-419CK
SENSOR COOKING CONDITION
UsingtheSENSOR function,foodiscookedwithoutfiguring
time,powerlevelorquantity. Whentheovensensesenough
steam from the food, it relays the information to its
microprocessor which will calculate the remaining cooking
timeandpowerlevelneededforbestresults. Whenthefood
is cooked, water vapor is developed. The sensor "senses"
thevapouranditsresistanceincreasegradually. Whenthe
resistance reaches the value set according to the menu,
supplementary cooking is started.
Thetimeofsupplementarycookingisdeterminedbyexperi-
mentwith each foodcategory and inputtedinto the LSI. An
example of how sensor works: (Potatoes)
1. Potatoes at room temperature. Vapor is emitted very
slowly.
2.Heat Potatoes. Moisture and humidity is emitted very
rapidly. You can smell the aroma as it cooks.
3.Sensor detects moisture and humidity and calculates
cooking time and variable power.
Cooking Sequence.
1. Touch one of the SENSOR pads.
NOTE: The oven should not be operated on sensor
immediately after plugging in the unit. Wait two
minutes before cooking on SENSOR.
2. The coil of shut-off relay (RY-1) is energized, the
turntablemotorareturnedon,butthepowertransformer
is not turned on.
3. After about 16 seconds, the cook relay (RY-2) is
energized. The power transformer is turned on,
microwaveenergyisproducedandfirststageisstarted.
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,thedisplayswitchesovertotheremainingcooking
time and the timer counts down to zero.
At this time, the door may be opened to stir, turn or
season food.
5. Whenthetimerreacheszero,anaudiblesignalsounds.
Theshut-offrelayandcookrelayarede-energizedand
the power transformer, oven lamp, etc. are turned off.
6. Opening the door or touching the STOP/CLEAR pad,
the time of the day will reappear on the display and the
oven will revert to an OFF condition. When the timer
reaches zero, an audible signal sounds.
OPERATION
DESCRIPTION OF OPERATING SEQUENCE

7
R-419CK
Figure O-2 Oven Schematic - Cooking Condition
Figure O-1 Oven Schematic - Off Condition
SCHEMATIC
NOTE: CONDITION OF OVEN
1. Door Closed
2. CLOCK APPEARS ON DISPLAY
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
MONITOR
FUSE 20A
MAGNETRON
TEMP.
FUSE
CAPACITOR 1.0µF
AC 2300V
AH SENSOR
SCHEMATIC
3. VARIABLE COOKING CONTROL "HIGH"
2. COOKING TIME PROGRAMMED
1. DOOR CLOSED
NOTE: CONDITION OF OVEN
4. "START" PAD TOUCHED
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
AH SENSOR
Note:* Indicates component s with potentioal above 250V.

8
R-419CK
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.
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
Key Unit
54321
09876
START
BEVERAGE
POPCORN
Power
Level
MINUTE
PLUS Fresh
Rolls/
muffins
Frozen
entrees
CUSTOM
HELP
Ground Meat
(SENSOR COOK)
Stop
Clear
Fresh
vegetables
G 8
G 9
G10
G11
G12
G13
G14
G 7 G 6 G 5 G 4 G 3 G 2 G 1
Chicken
Pieces
Steaks/
Chops Baked
Potatoes
Frozen
Vegetables
Clock Kitchen
Timer
Fish
Seafood
Frozen
Rolls/
muffins
Ground Meat
(COMPU DEFROST)
Reheat
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
contactsareclosedwhenthedoorisclosedandopenwhenthedoorisopen.Ifthedoorsensingswitch
(stopswitch)isgood,disconnecttheflatribboncablethatconnectsthekeyunittothecontrolunitand
make sure the door sensing switch is closed (either close the door or short the door sensing switch
connecter).UsetheKeyunitmatrixindicatedonthecontrolpanelschematicandplaceajumperwire
betweenthepinsthatcorrespondtotheSTOP/CLEARpadmakingmomentarycontact.Ifthecontrol
unitrespondsbyclearingwithabeepthekeyunitisfaultyandmustbereplaced.Ifthecontrolunitdoes
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.
J KEY UNIT 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 " steaks / chops " pad once.
(3)The oven is in Compu Defrost cooking condition.
(4)The oven will operate as follows
1ST STAGE 2ND STAGE
WEIGHT LEVEL TIME LEVEL TIME
0.5lb 60% 27sec. 40% 17sec.
LCOMPU DEFROST TEST
(5) If improper operation is indicated, the control unit is probably defective and should be checked.