Sharp R-21HC Service manual

R-21HC
SERVICE MANUAL
S7813R21HCP//
LIGHT DUTY
COMMERCIAL
MICROWAVE OVEN
MODEL
1000W/ R-21HC
TIME GUIDE FOR ONE
15 - 30 sec.
Bagel, Roll
Muffin, Pastry
Pie Slice
1 - 2 min.
Beverage, Soup
Large Sandwich
40 50
30 D E
20 C
1
F
1.5
G
H
I
B
2
J
A
0
K
L
M
COMM
ERCIA
N
L MICR
O
T
WAVE O
VEN
R-21HC
2 - 3 min.
Casserole, Stew
Chili, Chowder
Popcorn, 3.5 oz.
Popcorn, 1.5 oz.
10
SERVING
30 - 60 sec.
Hot Dog
Pizza Slice
Small Sandwich
6
O
S
R
P
Q
2.5
3
4
5
INSTRUCTIO
NS
With the door
closed,turn the
timer to
the desired
time. Oven
will begin
operating immedia
tely.
To shut oven
off manually,return
to "0".
timer
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 following parts may result in a severe,
possibly fatal, electrical shock. (High Voltage Capacitor, High
Voltage Power Transformer, Magnetron, High Voltage 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
GENERAL INFORMATION ................................................................................................................................... 4
OPERATION .......................................................................................................................................................... 6
TROUBLESHOOTING GUIDE .............................................................................................................................. 9
TEST PROCEDURE ............................................................................................................................................ 10
CONTROL PANEL ............................................................................................................................................... 16
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ................................................................ 19
PICTORIAL DIAGRAM ........................................................................................................................................ 26
CONTROL PANEL CIRCUIT .............................................................................................................................. 27
PRINTED WIRING BOARD ................................................................................................................................. 28
PARTS LIST ........................................................................................................................................................ 29
PACKING AND ACCESSORIES ......................................................................................................................... 31
SHARP CORPORATION
This document has been published to be used for after
sales service only.
The contents are subject to change without notice.
R-21HC
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 oven 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 the 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.
R-21HC
WARNING TO SERVICE PERSONNEL
Microwave ovens contain circuitry capable of producing very high voltage and current, contact with
following parts may result in a severe, possibly
fatal, electrical shock.
(Example)
High Voltage Capacitor, High Voltage Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..
Read the Service Manual carefully and follow all
instructions.
Don't Touch !
Danger High Voltage
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 power supply cord after the outer case is
installed.
7. Run the oven and check all functions.
Before Servicing
1. Disconnect the power supply cord ,
remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
and then
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.
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.
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. 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.
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.
1
R-21HC
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/cm2 at any point 5cm or more from the external surface of the oven, measured prior to acquisition
by a purchaser, and thereafter (through the useful life of the oven), 5 mW/cm2 at any point 5cm or more from the 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/cm2 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/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.
2
R-21HC
SERVICE MANUAL
PRODUCT DESCRIPTION
LIGHT DUTY
COMMERCIAL
MICROWAVE OVEN
GENERAL INFORMATION
R-21HC
FOREWORD
This Manual has been prepared to provide Sharp Electronics Corp.
Service Personnel with Operation and Service Information for the
SHARP MICROWAVE OVEN, R-21HC.
OPERATION
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.
TROUBLESHOOTING GUIDE AND
TEST PROCEDURE
Check the interlock switches and the door seal carefully. Special
attention should be given to avoid electrical shock and microwave
radiation hazard.
CONTROL PANEL
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.
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;
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.
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
SHARP PLAZA, MAHWAH,
NEW JERSEY 07430-2135
3
PARTS LIST
R-21HC
SPECIFICATION
ITEM
Power Requirements
Power Output
Case Dimensions
Cooking Cavity Dimensions
(1.0 Cubic Feet )
DESCRIPTION
120 Volts
14 Amperes
60 Hertz / Single phase, 3 wire grounded
1000 watts (IEC 705 Test Procedure)
Operating frequency of 2450MHz
Width 20-1/2" (520mm)
Height 12-1/8" (309mm)
Depth 16"
(406mm)
Width 13-7/8" (353mm)
Height 8-1/8" (207mm)
Depth 14-5/8" (370mm)
Control Complement
Light Up Dial (6 minutes)
No cooking control
Oven Cavity Light
Safety Standard
Yes
UL Listed
FCC Authorized
DHHS Rules, CFR, Title 21, Chapter 1, Subchapter J, NSF Certified
GENERAL INFORMATION
GROUNDING INSTRUCTIONS
This oven is equipped with a three prong grounding plug. It must be plugged into a wall receptacle that is properly installed
and grounded in accordance with the National Electrical Code and local codes and ordinances.
In the event of an electrical short circuit, grounding reduces the risk of electric shock by providing an escape wire for the
electric current.
WARNING: Improper use of the grounding plug can result in a risk of electric shock.
Electrical Requirements
The electrical requirements are a 120 volt 60 Hz, AC only, 15 amp. or
more protected electrical supply. It is recommended that a separate
Grounded
circuit serving only this appliance be provided. When installing this
3-Pronged Plug
Receptacle Box
appliance, observe all applicable codes and ordinances.
A short power-supply cord is provided to reduce risks of becoming
entangled in or tripping over a longer cord.
Where a two-pronged wall-receptacle is encountered, it is the personal
responsibility and obligation of the customer to contact a qualified
electrician and have it replaced with a properly grounded three-pronged
Grounding Pin
wall receptacle or have a grounding adapter properly grounded and
polarized. If the extension cord must be used, it should be a 3-wire, 15
amp. or higher rated cord. Do not drape over a countertop or table where
3-Pronged Receptacle
it can be pulled on by children or tripped over accidentally.
CAUTION: DO NOT UNDER ANY CIRCUMSTANCES CUT OR REMOVE THE ROUND GROUNDING PRONG FROM THIS PLUG.
4
R-21HC
OVEN DIAGRAM
12
9
1
3
2
14
13
11
4
15
16
8
1.
2.
3.
4.
5.
6.
7.
8.
10
6
5
7
9. Door hinges
10.Door seals and sealing surfaces
11.Door handle
12.Oven door with see-through window
13.Air ventilation cover and openings
14.Power supply cord
15.Air intake openings
16.Outer case cabinet
Back splash cover
Side splash cover
Oven light
Ceramic shelf
Control panel
Cavity face plate
Door latch openings
Door latches
TOUCH CONTROL PANEL
TIME GUIDE FOR ONE SERVING
15 - 30 sec.
Bagel, Roll
Muffin, Pastry
Pie Slice
30 - 60 sec.
Hot Dog
Pizza Slice
Small Sandwich
1 - 2 min.
Beverage, Soup
Large Sandwich
Popcorn, 1.5 oz.
2 - 3 min.
Casserole, Stew
Chili, Chowder
Popcorn, 3.5 oz.
50
40
30 D E
20 C
1
F
G
1.5
H
I
10
2
J
B
A
K
0
L
2.5
M
N
O
T
6
S
R
Q
5
P
3
4
INSTRUCTIONS
With the door closed,turn the timer to
the desired time. Oven will begin
operating immediately.
To shut oven off manually,return timer
to "0".
5
Light Up Dial for setting cooking time.
R-21HC
OPERATION
DESCRIPTION OF OPERATING SEQUENCE
If the secondary interlock switch and primary interlock relay
(RY1) fail with the 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,
and primary interlock relay(RY1), causing the monitor fuse
to blow.
The following is a description of component functions during
oven operation.
OFF CONDITION
Closing the door activates door sensing switch and secondary interlock switch. (In this condition, the monitor switch
contacts are opened.)
When oven is plugged in, 120 volts A.C. is supplied to the
control unit (Figure O-1).
COOKING CONDITION
When the Light Up Dial is turned, 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
RY-1
RY-2
CONNECTED COMPONENTS
Oven lamp/ Antenna motor/ Fan motor
Power transformer
2. 120 volts A.C. is supplied to the primary winding of the
power transformer and is converted to about 3.2 volts
A.C. output on the filament winding, and approximately
2150 volts A.C. on the high voltage winding.
3. The filament winding voltage heats the magnetron
filament and the H.V. winding voltage is sent to a voltage
doubler circuit.
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 power
transformer, oven lamp, etc. are turned off, and the
generation of microwave energy is stopped. The oven
will revert to the OFF condition.
6. When the door is opened during a cook cycle, monitor
switch, door sensing switch, secondary interlock switch,
relay (RY2) and primary interlock relay(RY1) are activated
with the following results. The circuits to the antenna
motor, the cooling fan motor, the oven lamp and the high
voltage components are de-energized, and the Light Up
Dial indicates time still remaining in the cook cycle when
the door was opened.
7. The monitor switch electrically monitors the operation of
the secondary interlock switch and primary interlock
relay(RY1) and is mechanically associated with the door
so that it will function in the following sequence.
(1) When the door opens from the closed position, the primary
interlock relay(RY1) and secondary interlock switch open
their contacts. Then the monitor switch contacts close.
(2) When the door is closed from the open position, the
monitor switch contacts open first. Then the contacts of
the secondary interlock switch and door sensing switch
close.
6
R-21HC
NOTE:
SCHEMATIC
NOTE: CONDITION OF OVEN
1. LIGHT UP DIAL OFF.
2. DOOR CLOSED.
THERMAL
THERMAL
CUT-OUT
CUT-OUT
125˚C (OVEN) 145˚C (MAG.)
MONITOR SWITCH
RY2
COOK
RELAY
RY1
PRIMARY
INTERLOCK
RELAY
AC120V
60 Hz
CONTROL UNIT
A3
CAPACITOR
0.94 µF
2400V
A1
OL
DOOR SENSING
SWITCH
OVEN
LAMP
FM
FAN
MOTOR
MAGNETRON
POWER
TRANSFORMER
A5
RECTIFIER
MONITOR
FUSE 20A
Indicates components with potential above 250 V.
AM
ANTENNA
MOTOR
SECONDARY
INTERLOCK SWITCH
Figure O-1 Oven Schematic-OFF Condition
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. LIGHT UP DIAL ON.
THERMAL
THERMAL
CUT-OUT
CUT-OUT
125˚C (OVEN) 145˚C (MAG.)
MONITOR SWITCH
RY2
COOK
RELAY
RY1
PRIMARY
INTERLOCK
RELAY
AC120V
60 Hz
CONTROL UNIT
A3
A1
OL
DOOR SENSING
SWITCH
OVEN
LAMP
FM
FAN
MOTOR
AM
ANTENNA
MOTOR
SECONDARY
INTERLOCK SWITCH
Figure O-2 Oven Schematic-Microwave cooking Condition
7
CAPACITOR
0.94 µF
2400V
MAGNETRON
POWER
TRANSFORMER
A5
RECTIFIER
MONITOR
FUSE 20A
R-21HC
DESCRIPTION AND FUNCTION OF COMPONENTS
(RY1) 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 DOOR SENSING SWITCH,
PRIMARY INTERLOCK RELAY (RY1), SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH FOR PROPER OPERATION.
(REFER TO CHAPTER "TEST PROCEDURE").
NOTE: MONITOR FUSE AND MONITOR SWITCH ARE
REPLACED AS AN ASSEMBLY.
DOOR OPEN MECHANISM
The door is opened by grasping the door handle, refer to
Figure D-1.
When the door handle is grasped, the handle lever is
pulled. And then the upper and lower latch heads are
moved upward by the handle lever, and they are released
from the latch hook. Now the door will open.
Latch Head
Handle
Lever
Latch Hook
Door
Handle
Latch Switch
Lever A
ANTENNA MOTOR
The antenna motor rotates the stirrer antenna located on the
bottom of the oven cavity, so that the food on the ceramic
shelf is cooked evenly during cooking. The antenna motor
may turn in either direction.
Secondary
Interlock
Switch
Latch
Lever
Latch Switch
Lever B
Latch Head
Latch Switch
Lever C
Monitor
Switch
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 food. It is then
exhausted through the exhausting air vents at the oven
cavity.
Door
Sensing
Switch
Figure D-1. Door Open Mechanism
DOOR SENSING AND SECONDARY INTERLOCK
SWITCHES
The secondary interlock switch is mounted in the upper
position of the latch hook and the door sensing switch in the
primary interlock system is mounted in the lower position of
the latch hook. The secondary interlock switch is activated
by the latch switch lever A. The latch switch lever A is
activated by the upper latch head. The door sensing switch
is activated by the latch switch lever C. The latch switch
lever C is activated by the lower latch head. When the door
is opened, the switches interrupt the power to all high
voltage components. A cook cycle cannot take place until
the door is firmly closed thereby activating both interlock
switches. The primary interlock system consists of the door
sensing switch and primary interlock relay located on the
control circuit board.
MONITOR FUSE
1. The monitor fuse blows when the contacts (COM-NO) of
the primary interlock relay (RY1) and secondary interlock
switch remain closed with the oven door open and when
the monitor switch closes.
2. If the wire harness or electrical components are shortcircuited, this monitor fuse blows to prevent an electric
shock or fire hazard.
THERMAL CUT-OUT 145˚C (MAGNETRON)
This thermal cut-out protects the magnetron against overheating. If the temperature goes up higher than 293˚F
(145˚C) because the fan motor is interrupted or the ventilation openings are blocked, the thermal cut-out will open and
line voltages to the high voltage transformer will be cut off
and the operation of the magnetron will be stopped. The
thermal cut-out will not resume.
MONITOR SWITCH
The monitor switch is activated (the contacts opened) by the
latch switch lever B on the latch hook while the door is
closed. The latch switch lever B is activated by the lower
latch head. The switch is intended to render the oven
inoperative, by means of blowing the monitor fuse, when the
contacts of the primary interlock relay (RY1) and secondary
interlock switch fail to open when the door is opened.
THERMAL CUT-OUT 125˚C (OVEN)
The thermal cut-out located on the top of the oven cavity is
designed to prevent damage to the oven if the food in the
oven catches fire due to over heating produced by improper setting of the cooking time or failure of control unit.
Under normal operation, the oven thermal cut-out remains
closed. However, when abnormally high temperatures are
reached within the oven cavity, the oven thermal cut-out
will open at 257˚F(125˚C) causing the oven to shut down.
The thermal cut-out will not resume.
Functions:
1. When the door is opened, the monitor switch contacts
close (to the ON condition) due to their being normally
closed. At this time the primary interlock relay (RY1) and
secondary interlock switch are in the OFF condition
(contacts open) due to their being normally open contact
switches.
2. As the door goes to a closed position, the monitor switch
contacts are first opened and then the door sensing
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 relay
8
R-21HC
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, primary interlock
relay (RY1), door sensing 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-BA015WRK0 as an assembly.
IMPORTANT: Whenever troubleshooting is performed with the power supply cord disconnected. It may in, some cases,
be necessary to connect the power supply cord after the outer case has been removed, in this event,
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the leads to the primary of the power transformer.
5. 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 power supply cord after the outer case is installed.
7. Run the oven and check all functions.
OFF
CONDITION
K RE RE RE RE RE CK CK CK
SECONDARY INTERLOCK SWITCH
PRIMARY INTERLOCK SYSTEM
MONITOR SWITCH
MONITOR FUSE
CONTROL PANEL
RELAY (RY2)
FOIL PATTURN ON P.W.B.
Home fuse or circuit breaker blows when
power cord is plugged into wall outlet.
Monitor fuse blows when power cord is
plugged into wall outlet.
Oven lamp does not light, and fan motor and
antenna motor do not operate.
Oven does not go into cook cycle when Light
Up Dial turned.
COOKING
CONDITION
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).
9
DIRTY OVEN CAVITY
J
LOW VOLTAGE
I
WRONG OPERATION
H
SHORTED IN POWER CORD
G
SHORT OR OPENED WIRING
F
ANTENNA MOTOR
F
COOLING FAN MOTOR
E
OVEN LAMP OR SOCKET
D
THERMAL CUT-OUT
PROBLEM
C
HIGH VOLTAGE CAPACITOR
CONDITION
B
H.V. RECTIFIER ASSEMBLY
POSSIBLE CASE
AND
DEFECTIVE PARTS
A
POWER TRANSFORMER
TEST PROCEDURE
MAGNETRON
CK = Check / RE = Replace
R-21HC
TEST PROCEDURES
PROCEDURE
LETTER
A
COMPONENT TEST
MAGNETRON ASSEMBLY TEST
1.
2.
3.
4.
5.
6.
7.
8.
9.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
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.
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.
Reconnect all leads removed from components during testing.
Reinstall the outer case (cabinet).
Reconnect the power supply cord after the outer case is installed.
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: silicon rectifier, high voltage capacitor and power transformer. 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 100% power more than 60 seconds cook time.
Allow the water to heat for 60 seconds, measuring with a stop watch or second hand of a watch.
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 34.7
to 64.6˚F(19.3 to 35.9˚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.
B
POWER TRANSFORMER TEST
1.
2.
3.
4.
5.
6.
7.
8.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
Disconnect the primary input terminals and measure the resistance of the transformer with an
ohmmeter. Check for continuity of the coils with an ohmmeter. On the R x 1 scale, the resistance of
the primary coil should be less than 1 ohm and the resistance of the high voltage coil should be
approximately 85 ohms; the resistance of the filament coil should be less than 1 ohm.
Reconnect all leads removed from components during testing.
Reinstall the outer case (cabinet).
Reconnect the power supply cord after the outer case is installed.
Run the oven and check all functions.
(HIGH VOLTAGES ARE PRESENT AT THE HIGH VOLTAGE TERMINAL, SO DO NOT ATTEMPT TO
10
R-21HC
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
MEASURE THE FILAMENT AND HIGH VOLTAGE.)
C
HIGH VOLTAGE RECTIFIER TEST
1.
2.
3.
4.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
Isolate the rectifier from the circuit. Using the highest ohm scale of the meter, read the resistance
across the terminals and observe, reverse the leads to the rectifier terminals and observe meter
reading. If a short is indicated in both directions, or if an infinite resistance is read in both directions,
the rectifier is probably defective and should be replaced.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
NOTE: Be sure to use an ohmmeter that will supply a forward bias voltage of more than 6.3 volts.
D
HIGH VOLTAGE CAPACITOR TEST
1.
2.
3.
4.
5.
6.
7.
8.
E
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
If the capacitor is open, no high voltage will be available to the magnetron. Disconnect input leads
and check for a short or open between the terminals using an ohmmeter.
Checking with a high ohm scale, if the high voltage capacitor is normal, the meter will indicate
continuity for a short time and should indicate an open circuit once the capacitor is charged. If the
above is not the case, check the capacitor with an ohmmeter to see if it is shorted between either of
the terminals and case. If it is shorted, replace the capacitor.
Reconnect all leads removed from components during testing.
Reinstall the outer case (cabinet).
Reconnect the power supply cord after the outer case is installed.
Run the oven and check all functions.
THERMAL CUT-OUT TEST 125˚C (OVEN)
1.
2.
3.
4.
5.
6.
7.
8.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
A continuity check across the thermal cut-out terminals should indicate a closed circuit unless the
temperature of the thermal cut-out reaches approximately 257˚F(125˚C).
An open thermal cut-out indicates overheating of the oven, exchange the 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.
Reconnect all leads removed from components during testing.
Reinstall the outer case (cabinet).
Reconnect the power supply cord after the outer case is installed.
Run the oven and check all functions.
THERMAL CUT-OUT TEST 145˚C (MAGNETRON)
1.
2.
3.
4.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
A continuity check across the thermal cut-out terminals should indicate a closed circuit. If the
temperature of the magnetron reaches approximately 293˚F(145˚C), the thermal cut-out opens. An
open thermal cut-out indicates overheating of the magnetron. Check for restricted air flow to the
magnetron, especially the cooling fan air guide.
5. Reconnect all leads removed from components during testing.
11
R-21HC
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
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.
F
SECONDARY INTERLOCK SWITCH TEST
1.
2.
3.
4.
5.
6.
7.
8.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
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 secondary interlock switch.
Reconnect all leads removed from components during testing.
Reinstall the outer case (cabinet).
Reconnect the power supply cord after the outer case is installed.
Run the oven and check all functions.
PRIMARY INTERLOCK SYSTEM TEST
DOOR SENSING SWITCH
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. 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 door sensing switch.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
PRIMARY INTERLOCK RELAY (RY1)
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect two (2) wire leads from the male tab terminals of the Primary Interlock Relay. Check the
state of the relay contacts using a ohmmeter. The relay contacts should be open. If the relay contacts
are closed, replace the circuit board entirely or the relay itself.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
G
MONITOR SWITCH TEST
1.
2.
3.
4.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
Before performing this test, make sure that the secondary interlock switch and the primary interlock
relay are operating properly, according to the above Switch Test Procedure. Disconnect the wire lead
from the monitor switch (COM) terminal. Check the monitor switch operation by using the ohmmeter
as follows. When the door is open, the meter should indicate a closed circuit. When the monitor switch
actuator is pushed by a screw driver through the lower latch hole on the front plate of the oven cavity
with the door opened (in this condition the plunger of the monitor switch is pushed in), the meter should
indicate an open circuit. If improper operation is indicated, the switch may be defective. After testing
the monitor switch, reconnect the wire lead to the monitor switch (COM) terminal and check the
continuity of the monitor circuit.
12
R-21HC
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
5.
6.
7.
8.
Reconnect all leads removed from components during testing.
Reinstall the outer case (cabinet).
Reconnect the power supply cord after the outer case is installed.
Run the oven and check all functions.
MONITOR
SWITCH
SCREW
DRIVER
WHT/ WHT
OHMMETER
H
BLOWN MONITOR FUSE TEST
1.
2.
3.
4.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
If the monitor fuse is blown when the door is opened, check the primary interlock relay, secondary
interlock switch and monitor switch according to the "TEST PROCEDURE" for those switches before
replacing the blown monitor fuse.
CAUTION: BEFORE REPLACING A BLOWN MONITOR FUSE, TEST THE PRIMARY INTERLOCK
RELAY, SECONDARY INTERLOCK SWITCH, DOOR SENSING SWITCH AND MONITOR
SWITCH FOR PROPER OPERATION.
If the monitor fuse is blown by improper switch operation, the monitor fuse and monitor switch must
be replaced with "monitor fuse and monitor switch assembly" part number FFS-BA015WRK0, even
if the monitor switch operates normally. The monitor fuse and monitor switch assembly is comprised
of a 20 ampere fuse and switch.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
I
CONTROL PANEL ASSEMBLY TEST
WARNING : To prevent an electric shock do not touch the electrical parts and the printed wiring
board. Because the control unit is "TRANSLESS CIRCUIT" and many electrical parts
are used at A.C. line voltage.
The 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 troubleshooting by unit replacement is described
according to the symptoms indicated.
Before testing,
1) Disconnect the power supply cord and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Disconnect the leads to the primary of the power transformer.
5) Ensure that these leads remain isolated from other components and oven chassis by using
insulation tape.
6) After that procedure, re-connect the power supply cord.
1. Control Panel
The following symptoms indicate a defective control unit.
1-1 In connection with LEDs
a) At a certain LED, all or some LEDs do not light up.
13
R-21HC
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
b) At a certain LED, brightness is low.
c) Only one LED does not light up.
d) All or some LEDs continue to light up.
e) A certain group of LEDs do not light up.
f) The LEDs flicker.
1-2 Other possible troubles caused by defective control unit.
a) Buzzer does not sound or continues to sound.
b) Clock is not possible.
c) Cooking time can not be set.
When testing is completed,
1) Disconnect the power supply cord and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Reconnect all leads removed from components during testing.
5) Re-install the outer case (cabinet).
6) Reconnect the power supply cord after the outer case is installed.
7) Run the oven and check all functions.
J
RELAY TEST
1. Disconnect the power supply cord and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the 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. Remove the outer case and check voltage between Pin No. 5 of the 3 pin connector (A) and the
common terminal of the relay RY1 on the control unit with an A.C. voltmeter.
The meter should indicate 120 volts, if not check oven circuit.
RY1 AND RY2 Relay Test
These relays are operated by D.C. voltage
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation.
DC. voltage indicated ................. Defective relay.
DC. voltage not indicated ........... Check diode which is connected to the relay coil. If diode is
good, control unit is defective.
RELAY SYMBOL
OPERATIONAL VOLTAGE
CONNECTED COMPONENTS
RY1
Approx. 19.0V D.C.
Oven lamp / Antenna motor / Cooling fan motor
RY2
Approx. 19.0V D.C.
Power transformer
The voltage under the condition when all LEDs light up.
8. Disconnect the power supply cord and then remove outer case.
9. Open the door and block it open.
10.Discharge high voltage capacitor.
11.Reconnect all leads removed from components during testing.
12.Re-install the outer case (cabinet).
13.Reconnect the power supply cord after the outer case is installed.
14.Run the oven and check all functions.
K
FOIL PATTERN ON THE PRINTED WIRING BOARD TEST
To protect the electronic circuits, this model is provided with a fine foil pattern added to the primary on
the PWB, this foil pattern acts as a fuse.
1. Foil pattern check and repairs.
1) Disconnect the power supply cord and then remove outer case.
14
R-21HC
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Follow the troubleshooting guide given below for repair.
STEPS
OCCURRENCE
CAUSE OR CORRECTION
1
Only pattern at "a" is broken.
*Insert jumper wire J1 and solder.
2
Pattern at "a" and "b" are broken.
*Insert the coil RCILF2003YAZZ between "c" and "d".
ORG
BRK
RY1
RY2
5) Make a visual inspection of the varistor.
Check for burned damage.
R11
c
ORG
RED
RED
a
b
(J1)
5
5
CN-A
d VRS1
,F
6) Reconnect all leads removed from components during testing.
7) Re-install the outer case (cabinet).
8) Reconnect the power supply cord after the outer case is installed.
9) Run the oven and check all function.
2. Follow the troubleshooting guide given below, if indicator does not light up after above check and
repairs are finished.
1) Disconnect the power supply cord and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Disconnect the leads to the primary of the power transformer.
5) Ensure that these leads remain isolated from other components and oven chassis by using
insulation tape.
6) After that procedure, re-connect the power supply cord.
7) Follow the troubleshooting guide given below for repair.
STEPS
1
OCCURRENCE
CAUSE OR CORRECTION
The rated AC voltage is not present between
Pin No. 5 of the 3-pin connector (A) and the
common terminal of the relay RY1.
Check supply voltage and oven power cord.
8) Disconnect the power supply cord and then remove outer case.
9) Open the door and block it open.
10) Discharge high voltage capacitor.
11) Reconnect all leads removed from components during testing.
12) Re-install the outer case (cabinet).
13) Reconnect the power supply cord after the outer case is installed.
14) Run the oven and check all functions.
15
R-21HC
CONTROL PANEL ASSEMBLY
OUTLINE OF CONTROL PANEL
4) ACL
A circuit to generate a signals which resets the LSI to the
initial state when power is supplied.
Control Unit
Control unit consists of LSI, power source circuit, synchronizing signal circuit, ACL circuit, buzzer circuit, encoder
circuit and indicator circuit.
5) Buzzer Circuit
The buzzer is responsive to signals from the LSI to emit
audible sounds (completion sound).
1) LSI
This LSI controls the encoder signal, relay driving signal
for oven function, buzzer signal and LED signal.
6) Door Sensing Switch (Stop Switch)
A switch to “tell” the LSI if the door is open or closed.
2) Power Source Circuit
This circuit generates voltage necessary in the control
unit.
Symbol
Voltage
VC
+5.0V
VR
+19.0V (*)
7) Relay Circuit
To drive the magnetron, fan motor, antenna motor and
light the oven lamp.
Application
LSI(I-1)
8) Encoder
The encoder generates the pulse signal, and the pulse
signal is sent to the LSI.
RELAY(RY1, RY2)
(*) The voltage under the condition when all LEDs light
up. The voltage VR will vary according to the quantity
of the LEDs which light up.
9) Indicator Circuit
Indicator elements are the Light-emitting diodes (LD1LD20).
This circuit consists of 4-digits and 5 segments.
3) Synchronizing Signal Circuit
The power source synchronizing signal is available in
order to compose a basic standard time in the clock
circuit. It accompanies a very small error because it
works on commercial frequency.
DESCRIPTION OF LSI
LSI(IZA902DR)
The I/O signal of the LSI(IZA902DR) are detailed in the following table.
Pin No.
Signal
I/O
Description
1
RST
IN
2
INT
IN
3
AVSS
IN
A/D converter power source voltage.
The power source voltage to drive the A/D converter in the LSI. Connected to GND.
4
VREF
IN
Reference voltage input terminal.
A reference voltage is applied to the A/D converter in the LSI. Connected to GND.
5
K0
IN
Terminal to change functions according to the model.
Signal in accordance with the model in operation is applied to set up its function.
6
7
K1
AVDD
IN
IN
8
NC
Connected to GND.
A/D converter power source voltage.
The power source voltage to drive the A/D converter in the LSI.
No connection terminal.
Auto clear terminal.
Signal is input to reset the LSI to the initial state when power is applied. Temporarily
set to “L” level the moment power is applied, at this time the LSI is reset. Thereafter
set at “H” level.
Signal coming from encoder.
When the encoder is turned, the contacts of encoder make pulse signals. And pulse
signals are input into INT.
16
R-21HC
9
S0
OUT
10
S1
OUT
11
S2
OUT
Digit selection signal.
Signal is input to the anodes of the light-emitting diodes (LD11 - LD15).
12
S3
OUT
Digit selection signal.
Signal is input to the anodes of the light-emitting diodes (LD16 - LD20).
13-14
NC
15
D0
OUT
16
D1
OUT
17
CNVS
IN
18
VSS
IN
Power source voltage: -0V.
The power source voltage to drive the LSI is input to VSS terminal. Connected to GND.
19
D2
OUT
Segment data signal.
Signal is input to the cathodes of the light-emitting diodes (LD1 ,LD6, LD11 and LD16).
20
D3
OUT
Segment data signal.
Signal is input to the cathodes of the light-emitting diodes (LD1-LD2, LD6-LD7, LD12,
LD16 and LD17).
21
D4
OUT
22
D5
OUT
D6-D7
OUT
Segment data signal.
Signal is input to the cathodes of the light-emitting diodes (LD1-LD3, LD6-LD8, LD11LD13, LD16-LD17 and LD18).
Segment data signal.
Signal is input to the cathodes of the light-emitting diodes (LD1-LD4, LD6-LD9, LD11LD14, LD16-LD18 and LD19).
Segment data signal.
Signal is input to the cathodes of all light-emitting diodes (LD1-D20).
23-25
26
NC
27
F0
Digit selection signal.
Signal is input to the anodes of the light-emitting diodes (LD1 - LD5).
Digit selection signal.
Signal is input to the anodes of the light-emitting diodes (LD6 - LD10).
No connection terminal.
Magnetron high-voltage circuit driving signal.
To turn on and off the relay (RY2). In 100% POWER operation, the signals hold “H”
level during microwave cooking and “L” level while not cooking.
Oven lamp, antenna motor and fan motor driving signal(Square Waveform :
16.7 msec.
60Hz)
H
To turn on and off the relay (RY1). The
square waveform voltage is delivered to
the relay (RY1) driving circuit and relay
L
During cooking
(RY2) control circuit.
Reference voltage input terminal.
A reference voltage is applied to the A/D converter in the LSI. Connected to GND.
No connection terminal.
IN
28
F1
OUT
29
F2
OUT
30
F3
IN
31-32
NC
Input signal which communicates the door open/close information to LSI.
Door closed; “L” level signal.
Door opened; “H” level signal.
Connected to CNTR.
Terminal not used.
Signal coming from encoder.
Signal similar to INT. Pulse signals are input into F3.
No connection terminal.
33
XOUT
OUT
34
XIN
IN
35
CNTR
OUT
Internal clock oscillation frequency control output.
Output to control oscillation input of XOUT.
Internal clock oscillation frequency input setting.
The internal clock frequency is set by inserting the ceramic filter oscillation circuit with
respect to XIN terminal.
Signal to sound buzzer.
A: Completion sound.
2.0 sec.
H : VC(+5V)
A
L : GND
36
VDD
IN
Power source voltage: +5.0V.
The power source voltage to drive the LSI is input to VDD terminal.
17
R-21HC
SERVICING
1. Precautions for Handling Electronic Components
This unit uses CMOS LSI in the integral part of the
circuits. When handling these parts, the following
precautions should be strictly followed. CMOS LSI have
extremely high impedance at its input and output
terminals. For this reason, it is easily influenced by the
surrounding high voltage power source, static electricity
charge in clothes, etc., and sometimes it is not fully
protected by the built-in protection circuit.
In order to protect CMOS LSI.
1) When storing and transporting, thoroughly wrap them
in aluminium foil. Also wrap PW boards containing
them in aluminium foil.
2) When soldering, ground the technician as shown in
the figure and use grounded soldering iron and work
table.
5) Re-connect the power supply cord after the outer
case is installed.
6) Run the oven and check all functions.
A. On some models, the power supply cord between the
touch control panel and the oven itself is so short that the
two can't be separated. For those models, check and
repair all the controls (sensor-related ones included) of
the touch control panel while keeping it connected to the
oven.
B. On some models, the power supply cord between the
touch control panel and the oven proper is so long
enough that they may be separated from each other. For
those models, therefore, it is possible to check and repair
the controls of the touch control panel while keeping it
apart from the oven proper; in this case you must short
both ends of the door sensing switch (on PWB) of the
touch control panel with a jumper, which brings about an
operational state that is equivalent to the oven door
being closed. As for the sensor-related controls of the
touch control panel, checking them is possible if the
dummy resistor(s) with resistance equal to that of the
controls are used.
(2) Servicing the touch control panel with power supply
from an external power source:
Disconnect the touch control panel completely from the
oven proper, and short both ends of the door sensing
switch (on PWB) of the touch control panel, which brings
about an operational state that is equivalent to the oven
door being closed. Connect an external power source to
the power input terminal of the touch control panel, then
it is possible to check and repair the controls of the touch
control panel; it is also possible to check the sensorrelated controls of the touch control panel by using the
dummy resistor(s).
approx. 1M ohm
2. Shapes of Electronic Components
E
CB
Transistor
2SA1267Y
2SC1740S
DTA143ES
DTA143ESXHZ
DTC143ES
3. Servicing of Touch Control Panel
We describe the procedures to permit servicing of the
touch control panel of the microwave oven and the
precautions you must take when doing so. To perform
the servicing, power to the touch control panel is available
either from the power line of the oven itself or from an
external power source.
(1) Servicing the touch control panel with power supply
of the oven :
CAUTION:
THE HIGH VOLTAGE TRANSFORMER OF THE MICROWAVE OVEN IS STILL LIVE DURING SERVICING AND PRESENTS A HAZARD .
Therefore, before checking the performance of the touch
control panel,
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, re-connect the power supply
cord.
After checking the performance of the touch control
panel,
1) Disconnect the power supply cord.
2) Open the door and block it open.
3) Re-connect the leads to the primary of the power
transformer.
4) Re-install the outer case (cabinet).
4. Servicing Tools
Tools required to service the touch control panel
assembly.
1) Soldering iron: 30W
(It is recommended to use a soldering iron with a
grounding terminal.)
2) Oscilloscope: Single beam, frequency range: DC 10MHz type or more advanced model.
3) Others: Hand tools
5. Other Precautions
1) Before turning on the power source of the control unit,
remove the aluminium foil applied for preventing
static electricity.
2) Connect the connector of the key unit to the control
unit being sure that the lead wires are not twisted.
3) After aluminium foil is removed, be careful that
abnormal voltage due to static electricity etc. is not
applied to the input or output terminals.
4) Attach connectors, electrolytic capacitors, etc. to
PWB, making sure that all connections are tight.
5) Be sure to use specified components where high
precision is required.
18
R-21HC
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
WARNING AGAINST HIGH VOLTAGE:
Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts may
result in severe, possibly fatal, electric shock.
(Example)
High Voltage Capacitor, Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..
WARNING:
Avoid possible exposure to microwave energy. Please follow the instructions below before
operating the oven.
1. Disconnect the power supply cord.
2. Visually check the door and cavity face plate for damage
(dents, cracks, signs of arcing etc.).
4. The door is bent or warped.
5. There are defective parts in the door interlock system.
6. There are defective parts in the microwave generating
and transmission assembly.
7. There is visible damage to the oven.
Carry out any remedial work that is necessary before
operating the oven.
Do not operate the oven if any of the following conditions
exist;
1. Door does not close firmly.
2. Door hinge, support or latch hook is damaged.
3. The door gasket or seal is damaged.
Do not operate the oven:
1. Without the RF gasket (Magnetron).
2. If the wave guide or oven cavity are not intact.
3. If the door is not closed.
4. If the outer case (cabinet) is not fitted.
WARNING FOR WIRING
To prevent an electric shock, take the following precautions.
1. Before wiring,
1) Disconnect the power supply cord.
2) Open the door and block it open.
3) Discharge the high voltage capacitor and wait for 60
seconds.
2. Don’t let the wire leads touch to the followiong parts;
1) High voltage parts:
Magnetron, High voltage transformer, High voltage
capacitor and High voltage rectifier assembly.
2) Hot parts:
Oven lamp, Magnetron, High voltage transformer,
and Oven cavity.
3) Sharp edge:
Bottom plate, Oven cavity, Waveguide flange,
Chassis support and other metallic plate.
4) Movable parts (to prevent a fault)
Fan blade, Fan motor, Switch, Switch lever and
antenna motor.
3. Do not catch the wire leads in the outer case cabinet.
4. Insert the positive lock connector until its pin is locked
and make sure that the wire leads do not come off even
if the wire leads are pulled.
5. To prevent an error function, connect the wire leads
correctly, referring to the Pictorial Diagram.
Please refer to ‘OVEN PARTS, CABINET PARTS, CONTROL PANEL PARTS, DOOR PARTS’, when carrying out any of
the following removal procedures:
OUTER CASE REMOVAL
To remove the outer case, proceed as follows.
1. Disconnect the power supply cord.
2. Open the oven door and block it open.
3. Remove the five (5) screws from rear and along the side
edge of case.
4. Slide the entire case back about 3cm to free it from
retaining clips on the cavity face plate.
5. Lift the entire case from the oven.
6. Discharge the H.V. capacitor before carrying out any
further work.
7. Do not operate the oven with the outer case removed.
CAUTION: 1. DISCONNECT OVEN FROM POWER SUP
PLY BEFORE REMOVING OUTER CASE.
2. DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN
COMPONENTS OR WIRING.
19
R-21HC
POWER TRANSFORMER REMOVAL
1. Disconnect the power supply cord and then remove
outer case.
2. Open the oven door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the filament leads of power transformer from
high voltage capacitor and the magnetron.
5. Disconnect the H.V. wire from the power transformer.
6. Disconnect the main wire harness from the power
transformer.
7. Remove the two (2) screws holding the transformer to
base plate.
8. Remove the transformer.
9. Now the power transformer is free.
HIGH VOLTAGE RECTIFIER ASSEMBLY AND HIGH VOLTAGE CAPACITOR REMOVAL
To remove the components, proceed as follows.
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 H.V. wire of the high voltage rectifier assembly
from the magnetron and the power transformer.
5. Disconnect the filament lead of the power transformer
from the high voltage capacitor.
6. Remove one (1) screw holding earth side terminal of the
high voltage rectifier assembly.
7. Disconnect all the leads and terminals of high voltage
rectifier assembly from the high voltage capacitor.
8. Now, the high voltage rectifier assembly should be free.
9. Remove one (1) screw holding the capacitor holder to
the oven cavity rear plate.
10.Remove one (1) screw holding the fan duct to the oven
cavity rear plate.
11.Release the capacitor holder from the fan duct.
12.Remove the capacitor from the capacitor holder.
13.Now, the capacitor should be free.
CAUTION: WHEN REPLACING HIGH VOLTAGE RECTIFIER AND HIGH VOLTAGE CAPACITOR,
GROUND SIDE TERMINAL OF THE HIGH
VOLTAGE RECTIFIER MUST BE SECURED
FIRMLY WITH A GROUNDING SCREW.
MAGNETRON REMOVAL
8. Release the tabs of air intake duct from the chassis
support and the oven cavity.
9. Move the air intake duct to the left.
10.Carefully remove four (4) screws holding magnetron to
waveguide, when removing the screws hold the
magnetron to prevent it from falling.
11.Remove the magnetron from the waveguide with care so
the magnetron antenna is not hit by any metal object
around the antenna.
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 high voltage wire of the high voltage
rectifier assembly and filament lead of the transformer
from the magnetron.
5. Remove the one (1) screw holding the airguide to the
magnetron and remove the airguide.
6. Remove the one (1) screw holding the insertion plate A
to the magnetron and remove the insertion plate A.
7. Remove the one (1) screw holding the chassis support
to the magnetron.
CAUTION: WHEN REPLACING THE MAGNETRON, BE
SURE THE R.F. GASKET IS IN PLACE AND
THE MAGNETRON MOUNTING SCREWS
ARE TIGHTENED SECURELY.
CONTROL PANEL ASSEMBLY REMOVAL
CONTROL PANEL ASSEMBLY
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 main wire harness from the control unit.
5. Remove the one (1) screw holding the control panel
assembly to the oven cavity front plate.
6. Lift up the control panel assembly.
7. Now, the control panel assembly is free.
CONTROL UNIT
8. Remove the five (5) screws holding the control unit to
the control panel frame.
9. Remove the control unit from the control panel frame.
10.Now, the control unit is free.
TIMER KNOB
11.After removing the control unit, release the tab of the
timer knob from the hole of the control panel.
12.Now, the timer knob is free.
NOTE: 1. Before attaching a new timer sheet, wipe off
remaining adhesive on the control panel frame
surfaces completely with a soft cloth soaked in
alcohol.
2. When attaching the timer sheet to the control
panel frame, adjust the upper edge and right
edge of the timer sheet to the correct position of
control panel frame.
3. Stick the timer sheet firmly to the control panel
frame by rubbing with a soft cloth so not to cause
scratches.
20
R-21HC
OVEN LAMP AND LAMP SOCKET REMOVAL
Oven lamp
socket
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. Lift up the oven lamp socket from air intake duct.
5. Pull the wire leads from the oven lamp socket by pushing
the terminal hole of the oven lamp socket with the small
flat type screw driver.
6. Now, the oven lamp socket is free.
Terminal
Wire lead
Terminal hole
Flate type small
screw driver
Figure C-1. Oven lamp socket
POSITIVE LOCK® CONNECTOR (NO-CASE TYPE) REMOVAL
Terminal
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. Push the lever of positive lock® connector.
5. Pull down on the positive lock ® connector.
Positive lock®
connector
1
Push
Lever
CAUTION: WHEN CONNECTING THE POSITIVE LOCK®
CONNECTORS TO THE TERMINALS, INSTALL THE POSITIVE LOCK® CONNECTOR
SO THAT THE LEVER FACES YOU
2
Pull down
Figure C-2. Positive lock® connector
ANTENNA MOTOR REMOVAL
remove the one (1) screw holding the antenna motor.
4. Remove the antenna motor shaft from the antenna
motor.
5. Now, the antenna motor is free.
1. Disconnect the power supply cord.
2. Remove the one (1) screw holding the base plate cover
to the base plate and remove the base plate cover.
3. Disconnect the wire leads from the antenna motor and
COOLING FAN MOTOR REMOVAL
REMOVAL
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 wire leads from the fan motor.
5. Remove the one (1) screw holding the capacitor holder
to the oven cavity rear plate.
6. Remove the one (1) screw holding the fan duct to the
oven cavity rear plate.
7. Release the tabs of the capacitor holder from fan duct.
8. Remove the fan duct from the oven.
9. Remove the fan blade from the fan motor shaft according
to the following procedure.
10.Hold the edge of the rotor of the fan motor by using a pair
of groove joint pliers.
CAUTION:
* Make sure that no metal pieces enter the gap
between the rotor and the stator of the fan motor
because the rotor is easily shaven by pliers and
metal pieces may be produced.
*
Do not touch the pliers to the coil of the fan motor
because the coil may be cut or injured.
* Do not disfigure the bracket by touching with the
pliers.
11.Remove the fan blade from the shaft of the fan motor by
pulling and rotating the fan blade with your hand.
12. Now, the fan blade will be free.
CAUTION:
* Do not reuse the removed fan blade because the
hole (for shaft) may be larger than normal.
13.Remove the two (2) screws holding the fan motor to the
fan duct.
14.Now, the fan motor is free.
INSTALLATION
1. Install the fan motor to the fan duct with the two (2)
screws.
2. Install the fan blade to the fan motor shaft according to
the following procedure.
3. Hold the center of the bracket which supports the shaft
of the fan motor on the flat table.
21
R-21HC
4. Install the fan blade to the shaft of fan motor by pushing
the fan blade with a small, light weight, ball peen hammer
or rubber mallet.
CAUTION:
* Do not hit the fan blade hard when installing because
the bracket may be disfigured.
* Make sure that the fan blade rotates smooth after
installation.
* Make sure that the axis of the shaft is not slanted.
5. Install the fan duct to the oven cavity rear plate with the
one (1) screw.
6. Insert the tabs of the capacitor holder to the fan duct.
7. Install the capacitor holder to the oven cavity rear plate
with the one (1) screw.
8. Re-connect the wire leads to the fan motor.
Coil
Shaft
Groove joint pliers
Stator
Gap
Bracket
Rotor
These are the positions
that should be pinched
with pliers
Stator
Rear View
Side View
Center of
bracket
Table
Shaft
Axis
Rotor
POWER SUPPLY CORD REPLACEMENT
Removal
9. Now, the power supply cord is free.
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 one (1) purse lock L holding the white and
the green wire leads of power supply cord and the wire
leads to the thermal cut-out (oven).
5. Remove the one (1) screw holding the green wire to the
cavity rear plate.
6. Disconnect the white wire lead of the power supply cord
from the main wire harness.
7. Disconnect the black wire lead of the power supply cord
from the fuse holder.
8. Release the power supply cord from the oven cavity rear
plate.
Re-install
1. Insert the moulding cord stopper of power supply cord
into the square hole of the oven cavity rear plate,
referring to the Figure C-3b.
2. Install the earth wire lead of power supply cord to the
cavity rear plate with one (1) screw and tighten the screw.
3. Connect the white wire lead of power supply cord to the
main wire harness correctly and black wire lead to the
fuse holder, referring to the Pictorial Diagram.
4. Hold the white and the green wire leads of power supply
cord and the wire leads to the thermal cut-out (oven) with
the one (1) purse lock L, referring to the Figure C-3a.
Power Supply Cord
Green Wire Lead
Screw
White Wire Lead
Thermal
Cut-out
(Oven)
Purse Lock L
Moulding
Cord Stopper
Black Wire Lead
Oven Cavity
Back Plate
Fuse Holder
Power
Supply Cord
Oven Cavity
Rear Plate
Chassis
Support
Main Wire
Harness
Square Hole
Figure C-3b. Power Supply Cord Replacement
Figure C-3a. Power Supply Cord Replacement
DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH REMOVAL
4. Remove the control panel assembly referring to
"CONTROL PANEL ASSEMBLY REMOVAL".
5. Disconnect the leads from all switches.
6. Remove the two (2) screws holding the latch hook to the
1. Disconnect the power supply cord and then remove
outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
22
R-21HC
oven cavity.
7. Remove the latch hook.
8. Push the retaining tab outward slightly and remove the
switch.
Re-install
1. Re-install each switch in its place. The door sensing
switch and monitor switch are in the lower position and
the secondary interlock switch is in the upper position.
2. Re-connect wire leads to each switch.
Refer to pictorial diagram.
3. Secure latch hook (with two (2) mounting screws) to
oven flange.
4. Make sure that the monitor switch is operating properly
and check continuity of the monitor circuit. Refer to
chapter "Test Procedure" and Adjustment procedure.
Latch Hook
Tabs
Secondary
Interlock
Switch
Tab
Monitor
Switch
Tab
Tab
Door
Sensing
Switch
Tab
Figure C-4. Switches
DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH ADJUSTMENT
1. Disconnect the power supply cord and then remove
outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
If the door sensing switch, secondary interlock switch and
monitor switch do not operate properly due to a
misadjustment, the following adjustment should be made.
4. Loosen the two (2) screws holding the latch hook to the
oven cavity front flange.
5. With door closed, adjust latch hook by moving it back and
forth, and up and down. In and out play of the door
allowed by the upper and lower position of the latch hook
should be less than 0.5mm. The vertical position of the
latch hook should be adjusted so that the door sensing
switch and secondary interlock switch are activated with
the door closed. The horizontal position of the latch hook
should be adjusted so that the plunger of the monitor
switch is pressed with the door closed.
6. Secure the screws with washers firmly.
7. Check the operation of all switches. If each switch has
not activated with the door closed, loosen screw and
adjust the latch hook position.
toward the oven face. Both results (play in the door)
should be less than 0.5mm.
2. The door sensing switch and secondary interlock switch
interrupt the circuit before the door can be opened.
3. Monitor switch contacts close when door is opened.
4. Re-install outer case and check for microwave leakage
around door with an approved microwave survey meter.
(Refer to Microwave Measurement Procedure.)
Latch Head
Handle
Lever
Latch Hook
Door
Handle
Latch Switch
Lever A
Secondary
Interlock
Switch
Latch
Lever
Latch Switch
Lever B
Latch Head
After adjustment, check the following.
1. In and out play of door remains less than 0.5mm when in
the latched position. First check upper position of latch
hook, pushing and pulling upper portion of door toward
the oven face. Then check lower portion of the latch
hook, pushing and pulling lower portion of the door
Latch Switch
Lever C
Monitor
Switch
Door
Sensing
Switch
Figure C-5. Latch Switch Adjustments
DOOR PARTS REMOVAL
in Figure C-6 to free engaging parts.
4. Pry the choke cover by inserting a putty knife as shown
in Figure C-6.
5. Release choke cover from door panel.
6. Now choke cover is free.
CHOKE COVER
1. Disconnect the power supply cord.
2. Open the door slightly.
3. Insert a putty knife (thickness of about 0.5mm) into the
gap between the choke cover and door frame as shown
23
R-21HC
RE-INSTALL OF THE DOOR
1. Re-install all door parts except the choke cover.
2. Catch two (2) pins of door panel on two (2) holes of upper
and lower oven hinges.
3. Re-install choke cover to door panel by pushing.
Choke Cover
NOTE: After any service to the door;
(A) Make sure that door sensing switch and secondary
interlock switch are operating properly. (Refer to
chapter "Test Procedures".).
(B) An approved microwave survey meter should be
used to assure compliance with proper microwave
radiation emission limitation standards. (Refer to
Microwave Measurement Procedure.)
Putty Knife
Door Frame
Figure C-6. Door Disassembly
7. Release two (2) pins of door panel from two (2) holes of
upper and lower oven hinges by lifting up.
8. Now, door sub assembly is free from oven cavity.
After any service, make sure of the following :
1. Door latch heads smoothly catch latch hook through
latch holes and that latch head goes through center of
latch hole.
2. Deviation of door alignment from horizontal line of cavity
face plate is to be less than 1.0mm.
3. Door is positioned with its face pressed toward cavity
face plate.
4. Check for microwave leakage around door with an
approved microwave survey meter. (Refer to Microwave
Measurement Procedure.)
Note: The door on a microwave oven is designed to act as
an electronic seal preventing the leakage of microwave
energy from oven cavity during cook cycle. This
function does not require that the door be air-tight,
moisture (condensation)-tight or light-tight. Therefore,
occasional appearance of moisture, light or sensing
of gentle warm air movement around oven door is not
abnormal and do not in themselves indicate a leakage
of microwave energy from oven cavity.
DOOR PANEL REMOVAL
9. Remove the four (4) screws holding the door panel to the
door frame.
10.Release door panel from seven (7) tabs of door frame by
sliding door panel downward.
11.Now, the door panel is free.
DOOR HANDLE REMOVAL
12.Release the latch spring from the tab of the latch angle
assembly.
13.Remove the two (2) screws holding the door handle and
the latch angle assembly through the door frame.
14.Now, door handle is free.
LATCH HEADS REMOVAL
15.Remove the one (1) screw holding the latch angle
assembly to the door frame.
16.Remove the latch angle assembly together with the latch
lever, latch spring and the upper and lower latch heads
from the door frame.
17.Release the latch lever together with the latch spring and
the latch heads from the latch angle assembly.
18.Release the two (2) latch heads from the latch lever.
19.Now, the upper and lower latch heads are free.
Pin
Upper
Oven
Hinge
Upper Oven
Hinge
FRONT DOOR GLASS REMOVAL
(After DOOR PANEL REMOVAL)
12.Remove the two (2) screws holding the glass stopper U
to the door frame and remove the glass stopper U.
13.Remove the two (2) screws holding the glass stopper R
to the door frame and remove the glass stopper R.
14.Slide the front door glass left at first and then slide
upwards to release it from the tabs holding it.
17.Now, the front door glass is free
Door
Panel
Lower
Oven
Hinge
Choke Cover
DOOR CASE REMOVAL
(After DOOR PANEL REMOVAL)
12.Straighten all tabs of the door case holding the door case
to the door frame.
13.Release door case from the door frame.
17.Now, the door case is free
NOTE: At this moment, the door badge is attached on the
door case.
Pin
Lower
Oven
Hinge
Figure C-7. Door Replacement
24
R-21HC
INSTALLATION OF CERAMIC SHELF
1. Disconnect the power supply cord.
2. Open the door and block it open.
3. Make sure that the smooth surface of the ceramic shelf
face up.
4. Make sure that the rubber packing without a fin of the
ceramic shelf faces the front of the oven.
NOTE: The three (3) rubber packings with the fins and the
one (1) rubber packing without a fin are attached to
the four (4) edges of the ceramic shelf. The one (1)
rubber packing without a fin is the front edge of the
ceramic shelf.
5. Put the front edge of the ceramic shelf into the front edge
of the oven cavity bottom plate.
6. Push down the rear edge of the ceramic shelf into the
oven cavity bottom plate.
7. Now, the ceramic shelf is installed.
WARNING
Make sure that the rubber packing is not caught between
the oven door and the oven cavity front plate, to avoid
possible exposure to excessive microwave energy.
Oven Cavity
Rear Edge
Push
Front Edge
25
Ceramic
Shelf
1
2
RY2
RY1
5 GRY
4
3 YLW
2
1 PNK
CN-A
ORG
RED
RED
F
3
26
4
COM.
YLW
PNK
N.O.
DOOR SENSING SWITCH
RED
WHT
5
RED
ORG
EARTH
BLK
RED
WHT
WHT
GRY WHT
BLK
WHT
ORG
ORG
RED
BRN
BLK
FUSE &
HOLDER
THERMAL
CUT-OUT
145°C(MAG.)
POWER TRANSFORMER
MAGNETRON
H.V.
CAPACITOR
HIGH VOLTAGE COMPONENTS
FAN MOTOR
NEUTRAL
GRN
POWER SUPPLY
CORD
4
5
E
Figure S-1. Pictorial Diagram
WHT
ANTENNA
MOTOR
CONNECTOR
GRY
ORG
BLK
B
WHT
NOTE:
Hot (ORG) wire must be
connected to the terminal
with blue mark on the
oven light socket.
BLUE MARK
OVEN LAMP
& SOCKET
BRN
3
N.C.
COM
MONMITOR
SWITCH
GRY
GRY
WHT
WHT
N.O.
THERMAL
CUT-OUT
125˚C(OVEN)
C
ORG
BLK
COM.
SECONDARY
INTERLOCK
SWITCH
HOT
D
2
H.V.
RECTIFIER
1
PRIMARY
INTERLOCK
RELAY
A
NOTE:
The gray wire of the main wire
harness must be connected to the
white wire of the power supply
cord.
R-21HC
6
A
B
C
G
H
6
D
E
F
G
H
AC120V
60Hz
10G471K1
R11
100 2w
(A)
c
a
b
C
(J1)
3
4
27
B
SW1
d
D2
R10 100k 1/2w
C2 2.2µ/160VAC
A
R60
100k
R62 4.7k
R63 4.7k
D4
–
+
Q1
2SC1740
5
LD1
20
LD6
2.30
LD11
D70
D74
D78
D82
VREF
K0
K1
4
5
6
LD3
LD2
LD8
1
D71
40
LD7
3.30
LD13
D75
LD12
3
8
LD18
LD17
7
13
D79
VSS
12
D83
18
7 AVDD
8
NC
9
S0
10
S1
11
S2
12
S3
13 NC
14 NC
15
D0
16
D1
17 CNVSS
RST
INT
AVSS
1
2
3
D72
D76
D80
D84
C5 47µ/16v
D2
D7
D6
D5
D4
D3
F1
F0
NC
D8
F2
XOUT
NC
NC
F3
LD4
1.30
LD9
4
LD14
9
LD19
14
19
24
23
22
21
20
28
27
26
25
29
33
32
31
30
D73
D77
D81
D85
C6 0.1µ/50v
VDD 36
CNTR 35
XIN 34
–
+
VC
LD5
2
LD10
5
LD15
10
LD20
15
C30
R31 47k
CF1
4MHz
GND
SP1
NOTE :
Q21
DTA143E
R42 3.3k
D30
Q20
DTC143E
–
+
D21
: IF NOT SPECIFIED 1/4w ± 5%
: IF NOT SPECIFIED 1SS270A
: IF NOT SPECIFIED 0.01µF / 16v
C20
0.1µ/50v
–
Q22
DTC143E
+
R41 1.5k
R40 4.7k
Q40
DTC143E
B
6
LD16
11
Q2
2SA1267Y
VR
RY1
RY2
(A)
A3
A1
COM
NO
COM
NO
DOOR SENSING
SWITCH
AC120V
60Hz
FAN MOTOR
ANTENNA MOTOR
OVEN LAMP
POWER
TRANSFORMER
4
5
Figure S-2. Control Panel Circuit
Q73
DTA143E
VRS1
D3
R4
510 1w
R6 4.7k
R3
510 1w
I-1 M34225M1
C4 0.1µ/50v
C61
C3 1000µ/25v
C60
R2
300
1w
R1
300
1w
ZD4-5 HZ6C3
D1
D1-4
IN4005
R70
430
A5
R61
100k
Q70
DTA143E
ZD4
ZD5
ZD1
ZD2
ZD3
Q72
DTA143E
2
Q71
DTA143E
C7
R5 1k
ZD6 HZ4C3
(JD)
1
R71
330
G
3
R72
240
H
R73
150
F
R30 4.7k
E
R21 4.7k
D
C21 10µ/35v
C
2
R74
100
A
D20
1
D22
FUSE1
R-21HC
6
A
B
C
6
D
E
F
G
H
R20 4.7k
ZD1-3 HZ11A3
R-21HC
1
2
4
3
5
6
A
A
LD6
LD5
LD4
D73
LD7
LD8
D72
D71
LD10
D77
D76
LD2
B
LD9
D75
D74
LD3
D70
LD1
B
LD11
D78
D79
LD12
SW1
A
B
D80
C
LD13
D81
C
D82
D83
D84
LD15
D85
R74
LD17
LD18
LD16
R73
R72
R71
R70
LD20
LD19
C
LD14
D
D
B
Q1
ZD6
ZD1
F
ICP1
C1
5
2
ZD3
1
(JA)
ORG
RED
RED (J1)
5
C2
D30
RY2
RY1
ORG
BRK
D4
D3
DIP
R10
ZD2
D1
D2
C4
C21
G
H
R2
+
C3
25
SP1
D21
D20
R11
ZD5
(JC)
R4
+
20
24
E
C5
E
Q2
R42 +
R1
R3
B
R5
R30
C7
(JD)
21
ZD4
E
R6
36
R40
R50
CF1
26
R20
C30
22
E
R41
R31
19
19
C60
F
+
C20
Q20
B
Q21
1
E
18
B
I-1
E
16
C61
R61
R60
B
E Q73
18
E
13
R63
23
B
14
R62
C6
17
R21
Q40
B
B
Q72
Q22
E
Q70
E C B
E
1
2
3
4
5
11
6
7
8
9
10
12
Q71
15
G
1
WH-1
2
1
1
CN-A
VRS1
D22
,F
SW2
H
Figure S-3. Printed Wiring Board
1
2
4
3
28
5
6
R-21HC
PARTS LIST
Note: The parts marked “∆” may cause undue microwave exposure.
The parts marked “*” are used in voltage more than 250V.
REF. NO.
PART NO.
DESCRIPTION
Q'TY
CODE
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
AK
AF
AH
AV
AV
AV
AU
AG
AG
AY
AQ
AP
AK
BM
BN
1
1
1
1
1
AX
AS
AM
AC
AF
1
1
1
1
1
1
1
1
1
1
1
1
2
1
4
3
1
16
1
1
20
1
1
1
1
1
1
4
2
2
1
1
1
1
2
1
1
1
1
1
2
2
1
BH
AG
AC
AF
AF
AA
AA
AA
AA
AM
AA
AA
AA
AD
AE
AA
AA
AA
AE
AK
AD
AB
AA
AB
AA
AB
AB
AB
AB
AA
AA
AA
AB
AD
AA
AA
AA
AA
AA
AA
AA
AA
AA
ELECTRIC PARTS
*
*
*
∆*
1- 1
1- 2
1- 3
1- 4
1- 5
1- 6
1- 7
1- 8
1- 9
1-10
1-11
1-12
1-13
1-14
1-15
FFS-BA015WRK0
QSW-MA051WRE0
QSW-MA135WRE0
FACCDA078WRE0
FH-DZA084WRK0
RC-QZA242WRE0
RMOTEA376WRE0
QFSHDA009WRE0
QSOCLA021WRE0
RLMPTA072WRE0
RMOTDA233WRE0
RTHM-A080WRE0
RTHM-A096WRE0
RTRN-A570WRE0
RV-MZA197WRE0
Monitor fuse and monitor switch assembly
Door sensing switch
Secondary interlock switch
Power supply cord
High voltage rectifier assembly
High voltage capacitor
Fan motor
Fuse holder
Oven lamp socket
Oven lamp
Antenna motor
Thermal cut-out 145 deg. (MAG)
Thermal cut-out 125 deg. (OVEN)
Power transformer
Magnetron
22222-
GCABUA674WRP0
GDAI-A311WRW0
GCOVHA393WRW0
GLEGPA074WRE0
GLEGPA076WRF0
Outer case cabinet
Base plate
Base plate cover
Foot
Leg
CPWBFA804WRK0
QCNCMA430DRE0
PTUBBA005WRE0
VCF2B62CA225K
VCEAB31VW108M
RC-KZA087DRE0
VCEAB31CW476M
RC-KZA087DRE0
VCKYD11CY103N
VCEAB31HW104M
VCEAB31VW106M
VCKYD11CY103N
VCKYD11CY103N
RCRS-A012DRE0
VHD1N4005E61B
VHD1SS270A/-1
VHD1SS270A/-1
VHD1SS270A/-1
QFS-AA005DRE0
RH-IZA902DRE0
VHPLTL1CHE/-3
VS2SC1740S/-3
VS2SA1267Y/-3
VSDTC143ES/-3
VSDTA143ES/1B
VSDTC143ES/-3
VSDTC143ES/-3
VSDTA143ES/-3
VRS-B13AA301J
VRS-B13AA511J
VRD-B12EF102J
VRD-B12EF472J
VRD-B12HF104J
VRS-L63DA101J
VRD-B12EF472J
VRD-B12EF472J
VRD-B12EF473J
VRD-B12EF472J
VRD-B12EF152J
VRD-B12EF332J
VRD-B12EF104J
VRD-B12EF472J
VRD-B12EF431J
Control unit assembly
3-pin connector (CN-A)
Insurating tube
Capacitor
2.2 uF
160VAC
Capacitor
1000 uF
35V
Capacitor
0.1 uF
50V
Capacitor
47 uF
16V
Capacitor
0.1 uF
50V
Capacitor
0.01 uF
16V
Capacitor
0.1 uF
50V
Capacitor
10 uF
35V
Capacitor
0.01 uF
16V
Capacitor
0.01 uF
16V
Ceramic resonator (CST4.00MGW)
Diode (1N4005E)
Diode (1SS270A)
Diode (1SS270A)
Diode (1SS270A)
IC PROTECTOR
LSI
Light emitting diode (LED)
Transistor (2SC1740S)
Transistor (2SA1267Y)
Transistor (DTC143ES)
Transistor (DTA143ESXHZ)
Transistor (DTC143ES)
Transistor (DTC143ES)
Transistor (DTA143ES)
Resistor
300 ohm
1W
Resistor
510 ohm
1W
Resistor
1.0k ohm
1/4W
Resistor
4.7k ohm
1/4W
Resistor
100k ohm
1/2W
Resistor
100 ohm
2W
Resistor
4.7k ohm
1/4W
Resistor
4.7k ohm
1/4W
Resistor
47k ohm
1/4W
Resistor
4.7k ohm
1/4W
Resistor
1.5k ohm
1/4W
Resistor
3.3k ohm
1/4W
Resistor
100k ohm
1/4W
Resistor
4.7k ohm
1/4W
Resistor
430 ohm
1/4W
CABINET PARTS
1
2
3
4
5
CONTROL PANEL PARTS
3- 1
3- 1A
3- 1B
C2
C3
C4
C5
C6
C7
C20
C21
C30
C60-61
CF1
D1-4
D20-22
D30
D70-85
FUSE1
I-1
LD1-20
Q1
Q2
Q20
Q21
Q22
Q40
Q70-73
R1-2
R3-4
R5
R6
R10
R11
R20-21
R30
R31
R40
R41
R42
R60-61
R62-63
R70
29
R-21HC
REF. NO.
R71
R72
R73
R74
RY1
RY2
SP1
SW1
VRS1
ZD1-3
ZD4-5
ZD6
3- 2
3- 2-1
3- 2-2
3- 3
3- 4
3- 5
PART NO.
VRD-B12EF331J
VRD-B12EF241J
VRD-B12EF151J
VRD-B12EF101J
RRLY-A110DRE0
RRLY-A098DRE0
RALM-A014DRE0
RVR-BA018WRE0
RH-VZA040DRE0
VHEHZ11A3//-1
VHEHZ6C3///-1
VHEHZ4C3///-1
FPNLCB390WRK0
HPNLTA137WRE0
GCOVAA264WRP0
TCAUAA076WRR0
JKNBKA606WRM0
XEPSD30P08XS0
DESCRIPTION
Resistor
330 ohm
1/4W
Resistor
240 ohm
1/4W
Resistor
150 ohm
1/4W
Resistor
100 ohm
1/4W
Relay (OMIF-S-124LM)
Relay (DU24D1-1P(M))
Buzzer (PKM22EPT)
Rotary encoder
Varistor (10G471K)
Zener diode (HZ11A3)
Zener diode (HZ6C3)
Zener diode (HZ4C3)
Panel sub assembly
Timer sheet
C/P case
User caution label
Timer knob
Screw; 3mm X 8mm
4- 1
4- 2
4- 3
4- 4
4- 5
4- 6
4- 7
4- 8
4- 9
4-10
4-11
4-12
4-13
4-14
4-15
4-16
4-17
4-18
4-19
4-20
4-21
4-22
4-23
4-24
4-25
4-26
4-27
4-28
4-29
4-30
4-31
4-32
4-33
4-34
4-35
4-36
FGLSPA062WRE0
*************
MLEVPA227WRF0
MLEVPA228WRF0
MLEVPA229WRF0
MSPRCA108WRE0
MSPRTA191WRE0
PHOK-A107WRF0
FDUC-A341WRP0
PSKR-A351WRP0
LBNDKA136WRP0
NFANJA029WRE0
PDUC-A697WRF0
FPLT-A007WRY0
PCUSGA504WRP0
PSKR-A348WRW0
GCOVHA404WRE0
LANGFA187WRP0
NSFTPA033WRF0
PCLICA032WRE0
PCLICA033WRE0
PCOVPA344WRF0
PCOVPA345WRF0
PCUSGA249WRP0
PCUSUA166WRP0
PCUSUA194WRP0
PCUSUA229WRP0
PDUC-A722WRF0
PFILWA060WRP0
PSHEPA644WRE0
PSKR-A347WRW0
PSKR-A349WRP0
PSKR-A359WRW0
PSPA-A112WRE0
PCUSGA378WRP0
PCUSUA507WRP0
Ceramic shelf
Oven cavity (Not a replaceable part)
Latch switch lever A
Latch switch lever B
Latch switch lever C
Latch lever spring
Switch lever B spring
Latch hook
Steam duct sub assembly
Steam guide
HV capacitor holder
Fan blade
Fan duct
Stirrer antenna assembly
Insertion cushion
Insertion plate A
VCP cap
Chassis support
Antenna motor shaft
Hand clip 4
Hand clip 5
Side splash cover
Back splash cover
Cushion
Cushion
Cushion
Cushion
Air intake duct
Lamp filter
Insertion sheet
Insertion plate B
Steam duct barrier
Air guide
Mica washer
Cushion
Cushion
5- 1
5- 2
5- 3
5- 4
5-4-1
5-4-2
5-4-3
5- 5
5- 6
5- 7
5- 8
5- 9
5-10
5-11
5-12
FDORFA322WRT0
PSHEPA649WRE0
FANGKA206WRY0
FCOV-A003WRK0
LSTPPA180WRF0
LSTPPA182WRF0
PGLSPA516WRE0
GWAKPA580WRM0
JHNDMA040WRW0
LANGKA874WRW0
LSTPPA181WRF0
MSPRTA190WRE0
PCUSUA506WRP0
XCPSD40P06000
LSUB-A083WRE0
Door panel assembly
Sealer film
Latch angle assembly
Door case assembly
Glass stopper R
Glass stopper U
Front door glass
Door handle
Handle lever
Latch lever
Latch head
Latch spring
Cushion
Screw : 4mm x 6mm
Sealed plate A
Q'TY
1
1
1
1
1
1
1
1
1
3
2
1
1
1
1
1
1
5
CODE
AA
AA
AA
AA
AL
AL
AG
AK
AF
AA
AA
AA
BF
AH
BA
AB
AL
AA
1
1
1
1
3
1
1
1
1
1
1
1
1
2
1
2
1
1
3
4
1
1
3
1
2
1
1
1
1
1
1
1
1
1
1
BL
—
AF
AF
AF
AC
AC
AL
BL
AY
AQ
AK
AM
BB
AB
AN
AG
AL
AK
AD
AD
AF
AF
AA
AC
AC
AB
AF
AD
AD
AL
AF
AM
AC
AL
AC
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
AZ
AB
AW
BQ
AK
AN
AU
AQ
AN
AR
AL
AD
AC
AA
AF
OVEN PARTS
∆
∆
∆
∆
∆
∆
∆
DOOR PARTS
∆
∆
∆
∆
30
R-21HC
REF. NO.
5-13
5-14
5-15
5-16
5-17
5-18
5-19
5-20
PART NO.
LSUB-A084WRE0
LSUB-A085WRE0
PCUSUA505WRP0
XCPSD40P08000
GCOVHA395WRF0
HBDGCA085WRE0
XEPSD40P25K00
PCUSUA508WRP0
Sealed plate B
Sealed plate C
Cushion
Screw : 4mm x 8mm
Choke cover
Door badge
Screw : 4mm x 25mm
Cushion
DESCRIPTION
66666666-
TINSEA759WRR0
FW-VZB684WRE0
TCAUAA166WRR0
TCAUAA241WRR0
TCAUAA243WRR0
TCAUAA245WRR0
TMAPCA747WRR0
LHLDWA012WRE0
Instruction book
Main wire harness
DHHS caution label
Monitor caution
Earth caution
Cover caution
Schematic diagram
Purse lock L
Q'TY
2
2
1
10
1
1
2
1
CODE
AE
AE
AC
AA
AK
AE
AB
AC
1
1
1
1
1
1
1
1
AF
BB
AB
AE
AC
AC
AC
AB
7
2
4
2
2
1
4
2
1
1
12
1
4
AA
AA
AA
AA
AB
AB
AA
AA
AA
AA
AA
AA
AA
MISCELLANEOUS
1
2
3
4
5
6
7
8
“SCREWS,NUTS AND WASHERS
7- 1
7- 2
7- 3
7- 4
7- 5
7- 6
7- 7
7- 8
7- 9
7-10
7-11
7-12
7-13
XHPSD40P08K00
XEPSD40P25000
LX-CZA038WRE0
LX-CZA052WRE0
LX-EZA042WRE0
XBPWW40P04000
XFPSD40P08000
XFTSD40P08000
XHPSD30P06000
XHTSD40P08RV0
XOTSD40P12000
XOTSF40P08000
XOTWW40P10000
Screw :
Screw :
Special
Special
Special
Screw :
Screw :
Screw :
Screw :
Screw :
Screw :
Screw :
Screw :
4mm x
4mm x
screw
screw
screw
4mm x
4mm x
4mm x
3mm x
4mm x
4mm x
4mm x
4mm x
8mm
25mm
4mm
8mm
8mm
6mm
8mm
12mm
8mm
10mm
HOW TO ORDER REPLACEMENT PARTS
To have your order filled promptly and correctly, please furnish the following information.
1. MODEL NUMBER
2. REF. NO.
3. PART NO.
4. DESCRIPTION
Order Parts from the authorized SHARP parts Distributor for your area.
Defective parts requiring return should be returned as indicated in the Service Policy.
TOP PAD ASSEMBLY
(FPADBA385WRK0)
PACKING AND ACCESSORIES
WRAP COVER
(SSAKHA034WRE0)
TRAY HOLDER
DOOR PROTECTION SHEET
(SPADFA435WRE0)
(SPADPA204WRE0)
6-1 INSTRUCTION BOOK
the avity
Into en C
v
O
BOTTOM PAD ASSEMBLY
(FPADBA386WRK0)
PACKING CASE
Not Replaceable Items.
31
SPAKCD116WRE0
R-21HC
2
1
4
3
7-3
6
5
OVEN AND CABINET PARTS
7-3
2-1
A
A
7-3
1-10
1-9
4-28
7-13
7-3
6-6
4-9
B
B
4-10
7-13
6-7
4-25
7-6
7-12
4-32
1-4
6-5
1-13
4-26
4-34
7-13
7-1
4-26
6-3
C
4-24
6-4
4-27
4-14
1-4
C
4-15
7-7
7-7
4-15
4-36
4-2
1-1
4-16
7-9
7-10
1-8
7-11
D
4-23
4-21
4-22
4-18
4-24
4-20
4-21
D
1-12
4-20
7-8
7-7
4-21
4-20
1-7
E
4-33
4-19
7-2
4-13
7-4
E
7-1
7-4
4-29
1-11
7-1
4-31
1-15
7-7
4-6
7-1
1-6
4-3
4-8
4-30
1-3
F
4-12
F
1-1
2-2
4-7
4-4
4-1
1-2
4-11
4-6
1-5
4-5
7-5
7-1
G
4-35
7-11
G
1-14
2-4
4-24
2-4
7-11 x2
2-3
H
4-17
H
2-5
7-8
1
2
7-11
4
3
32
5
6
R-21HC
2
1
4
3
6
5
3-1
CONTROL PANEL PARTS
3-5
A
A
3-2
3-2-1
3-5
3-2-2
B
B
3-3
C
C
3-4
DOOR PARTS
5-15
5-17
5-16
D
D
5-13
5-2
5-16
5-20
E
5-4-2
5-16
5-13
5-16
E
x4
5-4
5-1
5-4-1
5-4-3
5-16
x2
5-16
5-12
5-14
F
F
5-8
5-7
5-19
5-9
5-18
5-12
5-11
5-3
G
5-8
G
5-19
MISCELLANEOUS
5-6
5-5
6-2
6-8
5-10
H
H
Actual wire harness may be different from illustration.
1
2
4
3
33
5
6
R-21HC
COPYRIGHT © 1998 BY SHARP CORPORATION
ALL RIGHTS RESERVED.
No part of this publication may be reproduced, stored in retrieval systems, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission of the publisher.
'98 SHARP CORP. (7S2.530E) Printed in U.S.A
34