SHARP R2110J, R-2110JK, R-2110JW, R-2120JK, R-2120JW Service Manual
SERVICE MANUAL
S54M1R2110JW/
OVER THE RANGE
MICROWAVE OVEN
R-2110JK
R-2110JW
R-2120JK
R-2120JW
MODELS
R-2110JK
R-2110JW
R-2120JK
R-2120JW
In the interest of user-safety the oven should be restored to its original condition and only parts identical to those specified should
be used.
WARNING TO SERVICE PERSONNEL: Microwave ovens contain circuitry capable of producing very high voltage
and current. Contact with the following parts may result in a severe, possibly fatal, electrical shock. (Inverter unit
that includes High Voltage Capacitor, High Voltage Power Transformer, High Voltage Rectifier and Heat sink etc.,
and Magnetron, 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 .......................................................................................................................................................... 7
TROUBLESHOOTING GUIDE ............................................................................................................................ 11
TEST PROCEDURE ............................................................................................................................................ 13
TOUCH CONTROL PANEL ASSEMBLY ............................................................................................................ 22
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ................................................................ 29
PICTORIAL DIAGRAM ........................................................................................................................................ 38
POWER UNIT CIRCUIT ...................................................................................................................................... 39
LSI UNIT CIRCUIT ............................................................................................................................................... 41
PRINTED WIRING BOARD ................................................................................................................................. 43
PARTS LIST ........................................................................................................................................................ 44
PACKING AND ACCESSORIES ......................................................................................................................... 49
SHARP CORPORATION
This document has been published to be used for after
sales service only.
The contents are subject to change without notice.
R-2110JK
R-2110JW
R-2120JK
R-2120JW
PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO AVOID POSSIBLE EXPOSURE TO
EXCESSIVE MICROWAVE ENERGY
(a) Do not operate or allow the oven to be operated with the door open.
(b) Make the following safety checks on all ovens to be serviced before activating the magnetron or other microwave
source, and make repairs as necessary: (1) interlock operation, (2) proper door closing, (3) seal and sealing
surfaces (arcing, wear, and other damage), (4) damage to or loosening of hinges and latches, (5) evidence of
dropping or abuse.
(c) Before turning on microwave power for any service test or inspection within the microwave generating
compartments, check the magnetron, wave guide or transmission line, and cavity for proper alignment, integrity,
and connections.
(d) Any defective or misadjusted components in the interlock, monitor, door seal, and microwave generation and
transmission systems shall be repaired, replaced, or adjusted by procedures described in this manual before the
oven is released to the owner.
(e) A microwave leakage check to verify compliance with the Federal Performance Standard should be performed
on each oven prior to release to the owner.
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/cm
oven has been brought into compliance.
2
. The owner of the unit should be instructed not to use the unit until the
DANGER CAUTION
HIGH VOLTAGE
Do not energize a microwave oven with the outer case cabinet removed, because a microwave oven
generates High Voltage in the circuit.
If you intend to operate the oven employing the high frequency switching power converter circuit, you should
take special precautions to avoid an electrical shock hazard.
The high voltage transformer, high voltage capacitor and high voltage diode have energized high voltage
potential approx. 8 KV.
The aluminium heat sink is connected to the switching power transistor Collector pole, and has an energized
high voltage potential approx. 650V peak.
DO NOT ACCESS THE HIGH VOLTAGE TRANSFORMER, HIGH VOLTAGE CAPACITOR, HIGH
VOLTAGE DIODE AND HEAT SINK WHEN THE POWER SUPPLY IS CONNECTED TO AN ELECTRICAL
OUTLET.
WARNING TO SERVICE PERSONNEL
Microwave ovens contain circuitry capable of producing very high voltage and current, contact with
following parts
fatal, electrical shock.
(Example)
Inverter unit that includes High Voltage Capacitor,
High Voltage Power Transformer, High Voltage
Rectifier, Heat sink etc., and Magnetron, High
Voltage Harness etc..
Read the Service Manual carefully and follow all
instructions.
may result in a severe, possibly
Don't Touch !
Danger High Voltage
R-2110JK
R-2110JW
R-2120JK
R-2120JW
Before Servicing
1. Disconnect the power supply cord , and then
remove outer case.
2. Open the door and block it open.
3. To discharge high voltage capacitor, wait for 60 seconds.
WARNING:RISK OF ELECTRIC SHOCK.
DISCHARGE THE HIGH-VOLTAGE
CAPACITOR BEFORE SERVICING.
The high-voltage capacitor remains charged about 60
seconds after the oven has been switched off. Wait for 60
seconds and then short-circuit the connection of the highvoltage capacitor (that is the connecting lead of the highvoltage rectifier) against the chassis with the use of an
insulated screwdriver.
Whenever troubleshooting is performed the power supply
must be disconnected. It may in, some cases, be necessary
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. To discharge high voltage capacitor, wait for 60 seconds.
4. Disconnect the leads to the primary of the inverter unit.
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.
1. Disconnect the power supply cord, and then remove
outer case.
2. Open the door and block it open.
3. To discharge high voltage capacitor, wait for 60 seconds.
4. Reconnect the leads to the primary of the inverter unit.
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.
After repairing
1. Reconnect all leads removed from components during
testing.
2. Reinstall the outer case (cabinet).
3. Reconnect the power supply cord after the outer case 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. When the two minutes has elapsed (timer at zero)
carefully check that the water is now hot. If the water
remains cold carry out Before Servicing procedure and reexamine the connections to the component being tested.
When all service work is completed and the oven is fully
assembled, the microwave power output should be checked
and microwave leakage test should be carried out.
When the testing is completed,
1
R-2110JK
R-2110JW
R-2120JK
R-2120JW
SERVICING FOR INVERTER UNIT
WARNING
This inverter unit contains circuitry capable of producing high voltage and high current. Contact with any part
of the high voltage will result in electrocution.
DO NOT ACCESS ANY PARTS OF INVERTER UNIT WITH POWER SUPPLY CONNECTED.
DO NOT OPERATE INVERTER UNIT ITSELF.
It is dangerous because this unit contains high voltage components.
MICROWAVE MEASUREMENT PROCEDURE
A. Requirements:
1) Microwave leakage limit (Power density limit): The power density of microwave radiation emitted by a microwave oven
should not exceed 1mW/cm
by a purchaser, and thereafter (through the useful life of the oven), 5 mW/cm
2
at any point 5cm or more from the external surface of the oven, measured prior to acquisition
2
at any point 5cm or more from the external
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 switch shall prevent microwave radiation emission in excess of
5 mW/cm
2
at 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.
The placing of this standard load in the oven is important not only to protect the oven, but also to insure that any 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) Grasp the probe of the survey instrument and hold it perpendicular to the gap between the door and the body of the oven.
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) Check for leakage at the door screen, sheet metal seams and other accessible positions where the continuity of the metal
has been breached (eg., around the switches, indicator, and vents).
While testing for leakage around the door pull the door away from the front of the oven as far as is permitted by the closed
latch assembly.
4) Measure carefully at the point of highest leakage and make sure that the highest leakage is no greater than 4mW/cm
and that the primary interlock switch and secondary interlock switch do turn the oven OFF before any door movement.
NOTE: After servicing, record data on service invoice and microwave leakage report.
2
2
,
SERVICE MANUAL
R-2110JK
R-2110JW
R-2120JK
R-2120JW
OVER THE RANGE
MICROWAVE OVEN
R-2110JK / R-2110JW / R-2120JK / R-2120JW
FOREWORD
This Manual has been prepared to provide Sharp Electronics Corp.
Service Personnel with Operation and Service Information for the
SHARP OVER THE RANGE MICROWAVE OVEN, R-2110JK, R2110JW, R-2120JK, R-2120JW.
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.
PRODUCT DESCRIPTION
GENERAL INFORMATION
OPERATION
TROUBLESHOOTING GUIDE AND
TEST PROCEDURE
TOUCH CONTROL PANEL
COMPONENT REPLACEMENT
AND ADJUSTMENT PROCEDURE
WIRING DIAGRAM
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;
Inverter unit that includes High Voltage Capacitor, High
Voltage Power Transformer, High Voltage Rectifier, Heat
sink, etc., and Magnetron, High Voltage Harness etc.;
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 wrapper gives access to voltage above 250V.
All the parts marked “∆” on parts list may cause undue microwave
exposure, by themselves, or when they are damaged, loosened
or removed.
SHARP ELECTRONICS CORPORATION
PARTS LIST
SHARP PLAZA, MAHWAH,
NEW JERSEY 07430-2135
3
R-2110JK
R-2110JW
R-2120JK
R-2120JW
PRODUCT SPECIFICATION
ITEM DESCRIPTION
Power Requirements 120 Volts / 14 Amperes
60 Hertz
Single phase, 3 wire grounded
Power Output 1200 watts (IEC TEST PROCEDURE)
Operating frequency of 2450MHz
Case Dimensions Width 29-15/16"
Height 17"
Depth 15- 9/16"
Cooking Cavity Dimensions Width 22-9/16"
Height 10-9/16"
2.1 Cubic Feet Depth 15"
Hood lamp 2 bulbs, 20W x 2, Incandescent light bulbs
Hood fan Approx. 300 C.F.M./ 270 C.F.M.
Control Complement 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
R-2110JK/W
KEEP WARM pad, EASY DEFROST pad, POPCORN pad, SHORT CUTS pads
QUICK BREAKFAST pad, SNACK TIME pad, DINNER FAVORITS pad
TIMER/CLOCK pad, CUSTOM HELP pad, Numer selection pads
POWER LEVEL pad, STOP/CLEAR pad, START/MINUTE PLUS pad
FAN: HI/LO, LIGHT: HI/LO
R-2120JK/W
SENSOR CENTER pads, MEAL TIME pads
CUSTOM HELP pad, KEEP WARM PLUS pad, EASY DEFROST pad
SHORT CUTS pads, Numer selection pads, POWER LEVEL pad
Timer/Clock pad, Stop/Clear pad, START/Minute Plus pad
FAN: HI/LO, LIGHT: HI/LO
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. 44 lbs.
4
R-2110JK
3-Pronged Plug
Grounded
Receptacle Box
Grounding Pin
3-Pronged Receptacle
R-2110JW
R-2120JK
R-2120JW
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 oven is equipped with a 3-prong grounding plug. DO NOT UNDER ANY CIRCUMSTANCES CUT OR REMOVE THE
GROUNDING PIN FROM THE PLUG.
The power supply cord and plug must be connected to a separate 120 Volt AC, 60 Hz, 15 Amp. or more dedicated line, using
a grounded receptacle. The receptacle should be located inside the cabinet directly above the Microwave Oven/Hood
system mounting location.
OVEN DIAGRAM
8
1
2
3
4
1. Oven door with see-through window.
2. Door hinges.
3. Oven lamp.
It will light when oven is operating or door is open.
4. Door latches.
The oven will not operate unless the door is securely closed.
5. One touch door open button
6. Auto-Touch control panel.
7. Timer display: Digital display, 99 minutes 00 seconds.
8. Ventilation openings.
9. Light Cover.
10. Grease filters.
11. Power supply cord
CONTROL PANEL
8
11
7
6
8
5
10
109
5
R-2110JK
R-2110JW
R-2120JK
R-2120JW
R-2110JW R-2120JW
NOTE:
Some one-touch cooking features such as "MINUTE PLUS" 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.
6
OPERATION
DESCRIPTION OF OPERATING SEQUENCE
R-2110JK
R-2110JW
R-2120JK
R-2120JW
The following is a description of component functions during
oven operation.
OFF CONDITION
Closing the door activates the stop switch, primary interlock
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).
1. The display will show flashing "88 : 88".
To set any program or set the clock, you must first
touch the STOP/CLEAR button. The display will clear,
and " : " will appear .
COOKING CONDITION
Program desired cooking time touching the NUMBER pads.
When the START button 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)
RELAY CONNECTED COMPONENTS
RY1 Oven lamp / Fan motor / Stirrer motor
RY3, RY4 Hood fan motor
2. 120 volts A.C. is supplied to the inverter unit and is
converted in order to power of the magnetron by the high
frequency switching power circuit. The frequency is
approx. 33 _ 45 KHz.
3. The filament winding voltage of H.V. transformer heats
the magnetron filament and the H.V. winding gives a high
voltage approx. 2 KV to activaite a voltage doubler
circuit. Then approx. 4KV peak voltage power is supplied
to the magnetron cathode terminal.
4. The microwave energy produced by the magnetron is
channelled through the waveguide into the cavity feedbox, and then into the cavity where the food is placed to
be cooked.
5. Upon completion of the cooking time, the inverter unit,
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 monitor
switch, stop switch, secondary interlock switch and primary
interlock switch are activated with the following results.
The circuits to the stirrer motor, the cooling fan motor, the
turntable motor, and the inverter unit are de-energized,
and the touch screen displays the time still remaining in
the cook cycle when the door was opened.
7. The monitor switch is electrically monitoring the operation
of the secondary interlock switch and primary interlock
switch and is mechanically associated with the door so
that it will function in the following sequence.
(1) When the door opens from a closed position, the
primary interlock switch and secondary interlock
switch open their contacts, and then the monitor
switch contacts close. And contacts of the relay
(RY1) remain closed.
(2) When the door is closed from the open position, the
monitor switch contacts first open and the stop
switch contacts open, and then the contacts of the
secondary interlock switch and primary interlock
switch close. And contacts of the relay (RY1) open.
If the secondary interlock switch and primary interlock
switch fail with their contacts closed when the door is
opened, the closing of the monitor switch contacts will form
a short circuit through the monitor fuse, secondary interlock
switch, primary interlock switch and relay (RY1) causing the
monitor fuse to blow.
VARIABLE COOKING
When Variable Cooking Power is programmed, the 120
volts A.C. is supplied to the inverter unit which is operated
by the control unit. Microwave power operation is as follows:
The oven can be set for any of 11 power levels: 0% to
100%(HIGH). The variable cooking power less than 40% is
programmed at the ratio of ON time and OFF time within 32
sec./ cycle time base.
CONNECTION BETWEEN POWER SETTING AND ON/
OFF TIME OF INVERTER UNIT.
OUTPUT POWER SETTING ON TIME OFF TIME
Power 100%
Power 90%
Power 80%
Power 70% Continue operation
Power 60%
Power 50%
Power 40% 26 sec. 6 sec.
Power 30% 22 sec. 10 sec.
Power 20% 16 sec. 16 sec.
Power 10% 8 sec. 24 sec.
Power 0% 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 FOR R-2120J
Using the Sensor cooking function the food is cooked without
figuring time, power level or quantity. When the oven senses
enough steam from 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 and its resistance increases gradually. When the
7
R-2110JK
R-2110JW
R-2120JK
R-2120JW
resistance reaches the value set according to the menu,
supplementary 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.
MICROWAVE
2. Heat Potatoes. Moisture and humidity is emitted rapidly.
You can smell the aroma as it cooks.
AH SENSOR
MICROWAVE
VENTILATION METHODS HOT AIR EXHAUST
1. VERTICAL VENTING
For this venting method, hot air rising from the
conventional range below is drawn in by the hood fan
motor through the grease filters at the right and left sides
of the base cover, up through the right and left sides of
the oven cavity, then discharged vertically at rear center
top of the oven, into the customer's vent system.
: AIR FLOW
TO DUCT
HOOD FAN MOTOR
HOOD
INTAKE
DUCT R
GREASE
FILTER
2. HORIZONTAL VENTING
The air handing is the same as VERTICAL VENTING
except that the final air discharge is directed horizontally
out from the top rear of the oven into the customer's vent
system.
: AIR FLOW
HOOD FAN MOTOR
TO DUCT
3. Sensor detects moisture and humidity and calculates
cooking time and variable power.
Cooking Sequence.
1. Operate the oven in sensor cooking mode by referring to
the operation manual.
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 turntable
motor, oven lamp and cooling fan motor are turned on,
but the inverter unit is not turned on.
3. After about 32 seconds, the cook relay (RY-2) is
energized. The power transformer is turned on,
microwave energy is produced and first stage is started.
The 32 seconds is the cooling time required to remove
any vapor from the oven cavity and sensor.
NOTE: During this first stage, do not open the door or touch
STOP/CLEAR pad.
4. When the sensor detects the vapor emitted from the
food, the display switches over to the remaining cooking
time and the timer counts down to zero.
At this time, the door may be opened to stir, turn, or
season food.
5. When the timer reaches zero, an audible signal sounds.
The shut-off relay is de-energized and the inverter unit,
oven lamp, etc. are turned off.
6. Opening the door or touching the STOP/CLEAR pad, the
time of day will reappear on the display and the oven will
revert to an OFF condition.
HOOD
INTAKE
DUCT R
GREASE
FILTER
3. RE-CIRCULATION (INSIDE VENTING)
The air handing is the same as VERTICAL VENTING
except that the final air discharge is directed horizontally
through the upper front of the oven into the kitchen. In
this case, the accessory charcoal filter RK-260 must be
provided to filter the air before it leaves the oven.
: AIR FLOW
HOOD FAN MOTOR
HOOD EXHAUST
LOUVER
HOOD
INTAKE
DUCT R
GREASE
FILTER
CHARCOAL
FILTER
TO DUCT
8
FUSE
20A
120 V AC.
60 Hz
NOTE: CONDITION OF OVEN
SCHEMATIC
1. DOOR CLOSED
2. CLOCK APPEARS ON DISPLAY
BLKWHT
GRN
GND
HOOD FAN
THERMAL
CUT OUT
A5
B1
C5
B3
HOOD
MOTOR
RY4
RY3
High
N.C.
Low
HOOD
CAPACITOR
A1 A3 A9 A7
RY6
CONTROL UNIT
RY5
OVEN THERMAL
CUT-OUT
OVEN LAMP
RELAY
RY1
N.O.
COM.
R-2110JK
R-2110JW
R-2120JK
R-2120JW
PRIMARY INTERLOCK
SWITCH
C3
E2
E1
H1
H3
F3
F2
F1
HUMIDITY SENSOR
(Only for R-2120J)
STOP
SWITCH
A1
A3
INVERTER
UNIT
FA
FA
F
F
MAGNETRON
FUSE
20A
120 V AC.
60 Hz
HOOD
LAMP
HL
HL
Figure O-1. Oven Schematic-Off Condition
NOTE: CONDITION OF OVEN
1. DOOR CLOSED
2. COOKING TIME PROGRAMMED
3. VARIABLE COOKING CONTROL "HIGH"
4. "START" PAD TOUCHED
HOOD FAN
BLKWHT
THERMAL
CUT OUT
GRN
GND
SCHEMATIC
A5
B1
High
C5
B3
Low
HOOD
CAPACITOR
HOOD
A1 A3 A9 A7
MOTOR
RY4
RY3
N.C.
CONTROL UNIT
RY5
RY6
OVEN THERMAL
CUT-OUT
OVEN LAMP
RELAY
RY1
N.O.
COM.
OL
OVEN LAMP
C3
STMSTM
SECONDARY
INTERLOCK SWITCH
E2
STOP
SWITCH
E1
H1
H3
F3
F2
F1
HUMIDITY SENSOR
(Only for R-2120J)
FM
STIRRER MOTOR
PRIMARY INTERLOCK
SWITCH
MONITOR
SWITCH
FAN MOTOR WITH
TEMPERATURE FUSE
AC3
M
A1
A3
INVERTER
UNIT
FA
FA
F
F
MAGNETRON
HOOD
HL
LAMP
HL
OL
OVEN LAMP
STM
STM
SECONDARY
INTERLOCK SWITCH
STIRRER MOTOR
Figure O-2. Oven Schematic-Cooking Condition
9
FM
MONITOR
SWITCH
FAN MOTOR WITH
TEMPERATURE FUSE
AC3
M
R-2110JK
R-2110JW
R-2120JK
R-2120JW
DESCRIPTION AND FUNCTION OF COMPONENTS
DOOR OPEN MECHANISM
The door is opened by pushing the open button on the
control panel, refer to the Figure D-1.
When the open button is pushed, the open button pushes up
the open lever, and then the open lever pushes up the latch
head. The latch heads are moved upward and released
from latch hook. Now the door will open.
Latch heads
Latch hook
Stop switch
Door
Open lever
Primary
interlock switch
Monitor switch
Secondary
interlock switch
Figure D-1. Door Open Mechanism
STOP, PRIMARY INTERLOCK AND SECONDARY
INTERLOCK SWITCHES
The secondary interlock switch is mounted in the lower
position of the latch hook and the stop switch is mounted in
the upper position of the latch hook. The primary interlock
switch is also in the upper position of the latch hook. They
are activated by the latch heads on the door. When the door
is opened, the switches interrupt the circuit to all components. A cook cycle cannot take place until the door is firmly
closed thereby activating both interlock switches.
MONITOR SWITCH
The monitor switch is activated (the contacts opened) by the
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 switch and secondary interlock switch fail to open
when the door is opened.
Functions:
1. When the door is opened, the monitor switch contact
close (to the ON condition) due to their being normally
closed. At this time the primary interlock switch and
secondary interlock switch are in the OFF condition
(contacts open) due to their being normally open contact
switches. And the contacts of relay (RY1) are in the ON
condition (contacts close).
2. As the door goes to a closed position, the monitor switch
contacts are first opened and the stop switch contacts
close, and then the primary interlock switch and the
secondary interlock switch contacts close. (On opening
the door, each of these switches operate inversely.)
3. If the door is opened, and the primary interlock switch
and secondary interlock switch contacts fail to open, the
monitor fuse blows simultaneously with closing of the
monitor switch contacts.
CAUTION: BEFORE REPLACING A BLOWN MONITOR
FUSE TEST THE STOP SWITCH, PRIMARY
INTERLOCK SWITCH, SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH FOR
PROPER OPERATION. (REFER TO CHAPTER "TEST PROCEDURE").
NOTE: MONITOR FUSE AND SWITCH ARE REPLACED
AS AN ASSEMBLY
THERMAL CUT-OUT (HOOD )
This thermal cut-out located on the right base plate. It is
designed to automatically turn on the hood fan motor
whenever the hot air rising from the conventional range
below causes the temperature at the thermal cut-out to rise
to 140˚F (60˚C) or higher, thus removing this hot air from
around microwave oven. When the temperature around the
thermal cut-out drops to 113˚F (45˚C) or lower, the thermal
cut-out shuts off the hood fan motor.
THERMAL CUT-OUT (OVEN )
This thermal cut-out is located on the top of the oven cavity.
It is designed to prevent damage to the oven unit if the food
in the oven catches fire due to overheating produced by
improper setting of cooking time or failure of control unit.
Under normal operation, the thermal cut-out remains closed.
However, the thermal cut-out will open at 293˚F (145˚C)
causing the oven to shut down.
COOLING FAN MOTOR
The cooling fan motor drives a blade which draws external
cool air. This cool air is directed through the air vanes
surrounding the magnetron and cools the magnetron. This air
is channelled through the oven cavity to remove steam and
vapors given off from the heating foods. It is then exhausted
through the exhausting air vents at the oven cavity.
HOOD FAN MOTOR
The hood fan motor is a two-speed, single-phase, double
pole induction type, requiring a hood fan capacitor. It is
located outside the upper rear part of the oven cavity, is to
remove, from around the oven, hot air rising from the
conventional electric or gas range over which it is installed.
This air is then expelled either vertically or horizontally
through the customer supplied duct system, or discharged
back into the kitchen.
STIRRER MOTOR
The stirrer motors drive the stirrer fans to stir the microwave
radiation from the waveguide.
HOOD LAMP
The hood lamps are mounted at the hood lamp angle. The
hood lamps can be turned off and on by touching the Light
Options pad. And also the brightness can be varied to high
or low by touching the Light Options pad.
10
R-2110JK
R-2110JW
R-2120JK
R-2120JW
TROUBLESHOOTING GUIDE
Never touch any part in the circuit with your hand or an uninsulated tool while the power supply is connected.
When troubleshooting the microwave oven, it is helpful to follow the Sequence of Operation in performing the checks. Many
of the possible causes of trouble will require that a specific test be performed. These tests are given a procedure letter which
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 switch and secondary interlock switch before replacing the monitor fuse. 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 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. To discharge high voltage capacitor, waite for 60 seconds.
4. Disconnect the leads to the primary of the inverter unit.
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. To discharge high voltage capacitor, waite for 60 seconds.
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
R-2110JK
R-2110JW
R-2120JK
R-2120JW
CK LOW VOLTAGE
CK NO POWER AT OUTLET
RE SHORTED IN POWER CORD
CK OPENED OR SHORTED WIRING
CK HOOD MOTOR CAPACITOR
RE HOOD LAMP OR SOCKET
RE STIRRER MOTOR
RE FAN MOTOR
RE OVEN LAMP OR SOCKET
O HUMIDITY SENSOR (R2120J)
N FOIL PATTERN ON P.W.B.
M EASY DEFROST
L RELAY (RY-4)
L RELAY (RY-3)
L RELAY (RY-5, RY-6)
L RELAY (RY-1)
K KEY UNIT
J CONTROL UNIT
I HOOD FAN MOTOR
H HOOD THERMAL CUT-OUT
G MONITOR FUSE
F MONITOR SWITCH
E
STOP SWITCH
D PRIMARY INTERLOCK SWITCH
D SECONDARY INTERLOCK SWITCH
C OVEN THERMAL CUT-OUT
B INVERTER UNIT
A MAGNETRON
CK = Check / RE = Replace
POSSIBLE CASE AND
DEFECTIVE PARTS
TEST PROCEDURE
PROBLEM
Home fuse blows when power cord is plugged into wall receptacle.
Monitor fuse blows when power cord is plugged into wall receptacle.
Display does not illuminate when power cord is first plugged into wall receptacle.
Display does not operate properly when STOP/CLEAR key is touched. (The
time of day should appear on the display with beep sound during normal con-
dition.)
Oven lamp does not light with door is opened.
Hood fan motor operates when power cord is first plugged into wall receptacle.
Temperature of oven base seems more than 140˚F (60˚C) because of operation
of the range below. But hood fan motor does not turn on automatically. (Normal-
ly, food fan motor should be operating at low speed.)
Hood lights do not turn on when Light pad is pressed.
Hood fan motor does not rotate at all with touched Fan pad.
Speed of the hood fan motor does not change when the Fan Options pad is
touched for this function.
Oven lamp does not light in cook cycle. (But it does light when door is opened.)
Fan motor does not operate. (Oven lamp and strrer motor 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).
Variable cooking does not operate properly except Cooking Power 100% mode.
Stirrer motor does not operate. (Other parts operate.)
Oven goes into EASY DEFROST but food is not defrosted well.
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 32 seconds after starting.
CONDITION
OFF
CONDITION
12
IDLE
CONDITION
COOKING
CONDITION
MICROWAVE
SENSOR
COOKING
CONDITION
TEST PROCEDURES
R-2110JK
R-2110JW
R-2120JK
R-2120JW
PROCEDURE
LETTER
A MAGNETRON ASSEMBLY TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. To discharge high voltage capacitor, wait for 60 seconds.
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. To test for a shorted magnetron, connect the ohmmeter leads between the magnetron filament leads 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 should
only be used if above tests do not indicate a faulty magnetron and there is no defect in the following
components or wiring: inverter unit. This test will require 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. Fill the measuring cup with 16 oz. (453cc) of tap water and measure the temperature of the water with 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 the cup of water in the oven. Operate oven at POWER 10(HIGH) selecting more than 60 seconds
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. Subtract the cold water temperature from the hot water temperature. The normal result should be 39.2 to
63˚F(21.8 to 35˚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 rise in water
temperature) which would reduce cooking time. Because cooking time can be adjusted to compensate for
power output, the magnetron tube assembly should be replaced only if the water temperature rise test
indicates a power output well beyond the normal limits. The test is only accurate if the power supply line
voltage is 120 volts and the oven cavity is clean.
COMPONENT TEST
B INVERTER UNIT TEST
WARNING: DO NOT TOUCH THE COMPONENTS OF THE INVERTER UNIT WHILE INVERTER
UNIT IS ENERGIZED. IT IS DANGEROUS BECAUSE THIS HAS HIGH VOLTAGE
COMPONENTS.
CAUTION: DO NOT OPERATE INVERTER UNIT BY ITSELF.
CAUTION: DO NOT CONNECT THE OVEN TO WALL OUTLET WITHOUT THE OUTER CASE
INSTALLED.
Before checking the inverter unit, curry out following 4 steps.
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. To discharge high voltage capacitor, wait for 60 seconds.
4. Make sure that the wire leads and the connectors are connected correctly to the inverter unit, control unit
and magnetron.
13
R-2110JK
R-2110JW
R-2120JK
R-2120JW
TEST PROCEDURES
PROCEDURE
LETTER
Chart for checking the defective inverter unit
No power at full power output cooking
Magnetron is defective. Exchange the magnetron.
NO
Exchange the Inverter unit
Brown monitor fuse
The secondary interlock switch, primary interlock
switch and the monitor switch are operating properly.
YES
Exchange the Inverter unit
C OVEN THERMAL CUT-OUT TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. To discharge high voltage capacitor, wait for 60 seconds.
4. A continuity check across the thermal cut-out terminals should indicate a closed circuit unless the
temperature of the thermal cut-out reaches approximately 293˚F(145˚C).
An open thermal cut-out indicates overheating of the oven, exchange the oven thermal cut-out and
check 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.
CAUTION: IF THE THERMAL CUT-OUT INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE,
REPLACE THERMAL CUT-OUT.
COMPONENT TEST
YES
NO
Check the switches according to
the switch Test Procedure
D PRIMARY INTERLOCK SWITCH AND SECONDARY INTERLOCK SWITCH TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. To discharge high voltage capacitor, wait for 60 seconds.
4. Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (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 primary interlock switch or 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.
E STOP SWITCH TEST
STOP SWITCH
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. To discharge high voltage capacitor, wait for 60 seconds.
14
Loading...