Sharp | R-204 | Service manual | Sharp R-204 Service manual

R-204EWA
SERVICE MANUAL
S6115R204EPWA
MICROWAVE OVEN
MODEL
ON
DEF.
EXPRESS
DEFROST
POWER
LEVEL
LBS.
R-204EWA
QTY. CHECK
MINUTE
PLUS
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.
TIMER
CLOCK
STOP
CLEAR
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
TOUCH CONTROL PANEL ................................................................................................................................. 18
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ................................................................ 22
PICTORIAL DIAGRAM ........................................................................................................................................ 28
CONTROL PANEL CIRCUIT ............................................................................................................................... 29
PARTS LIST ........................................................................................................................................................ 31
PACKING AND ACCESSORIES ......................................................................................................................... 32
SHARP CORPORATION
This document has been published to be used for after
sales service only.
The contents are subject to change without notice.
R-204EWA
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/cm2. The owner of the unit should be instructed not to use the unit
until the oven has been brought into compliance.
R-204EWA
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.
After repairing
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.
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.
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R-204EWA
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.
NOTE: After servicing, record data on service invoice and microwave leakage report.
2
R-204EWA
SERVICE MANUAL
PRODUCT DESCRIPTION
MICROWAVE OVEN
R-204EWA
GENERAL INFORMATION
FOREWORD
This Manual has been prepared to provide Sharp Electronics Corp.
Service Personnel with Operation and Service Information for the
SHARP MICROWAVE OVEN, R-204EWA.
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.
TOUCH 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 not any 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-204EWA
PRODUCT DESCRIPTION
SPECIFICATIONS
ITEM
DESCRIPTION
Power Requirements
120 Volts
60 Hertz
Single phase, 3 wire grounded
Power Consumption
1250W / Approx. 10.6 Amperes
Power Output
800 W nominal of RF microwave energy (IEC Test procedure)
Operating frequency 2450 MHz
Case Dimensions
Width 18-1/8"
Height 11-3/8"
Depth 14-5/8"
Cooking Cavity Dimensions
(0.8 Cubic feet)
Width 12-3/8"
Height 8-3/8"
Depth 13"
Control Complement
Touch Control System
Clock (1:00 - 12:59)
Timer (0 - 99 minutes 99 seconds)
Microwave Power for Variable Cooking
Repetition Rate;
Oven Cavity Light
Safety Standard
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
EXPRESS DEFROST pad, MINUTE PLUS pad
Instant Start pads, Number selection pads
POWER LEVEL pad, TIMER / CLOCK pad
STOP/CLEAR pad, START pad
Yes
UL Listed.
FCC Authorized
DHHS Rules, CFR, Title 21, Chapter 1, Subchapter J
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 115 -120 volt 60 Hz, AC only,
4
R-204EWA
15 or 20 amp. fused electrical supply. It is recommended that a separate circuit
serving only this appliance be provided. When installing this appliance, observe all
applicable codes and ordinances.
A short power-supply cord is provided to reduce risks of becoming entangled in or
tripping over a longer cord.
Where a two-pronged wall-receptacle is encountered, it is the personal responsibility and obligation of the customer to contact a qualified electrician and have it
replaced with a properly grounded three-pronged wall receptacle or have a
grounding adapter properly grounded and polarized. If the extension cord must be
used, it should be a 3-wire, 15 amp. or higher rated cord. Do not drape over a
countertop or table where it can be pulled on by children or tripped over accidentally.
Grounded
Receptacle Box
3-Pronged
Plug
Grounding Pin
3-Pronged Receptacle
CAUTION: DO NOT UNDER ANY CIRCUMSTANCES CUT OR REMOVE THE ROUND GROUNDING PRONG FROM
THIS PLUG.
OVEN DIAGRAM
3
9
8
10
12
7
13
11
6
2 1
4
5
1. Oven door with see-through window
2. Safety door latches
3. Door hinges
4. Door seals and sealing surfaces
5. Turntable motor shaft
6. Removable turntable support
7. Removable turntable
8. Ventilation openings (Rear)
9. Oven lamp
10. Wave guide cover
11. Door open handle
12. Control panel
13. Power supply cord
TOUCH CONTROL PANEL
Time display
Indicators
See NOTE.
ON
DEF.
EXPRESS
DEFROST
LBS.
QTY. CHECK
MINUTE
PLUS
See NOTE.
NOTE:
The directed features are disabled after one minute 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.
POWER
LEVEL
STOP
CLEAR
5
TIMER
CLOCK
R-204EWA
OPERATION
DESCRIPTION OF OPERATING SEQUENCE
relay (RY2) 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
secondary interlock switch, door sensing switch and
primary interlock relay (RY2) 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.
If the secondary interlock switch and primary interlock relay
(RY2) fail with the contacts closed when the door is opened,
the closing of the monitor switch contacts will form a short
circuit through the C/T fuse and primary interlock relay
(RY2), causing the C/T 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).
1. The display will show flashing "88:88".
2. To set any program or set the clock, you must first touch
the STOP/CLEAR pad. The display will clear, and " : "
will appear.
COOKING CONDITION
Program desired cooking time by touching the NUMBER
pads. And program the power level by touching the POWER
LEVEL pad.
When the START pad is touched, the following operations
occur:
POWER LEVEL COOKING
When Variable Cooking Power is programmed, the 120
volts A.C. is supplied to the power transformer intermittently
through the contacts of relay (RY-2) which is operated by the
control unit within a 32 second time base. Microwave power
operation is as follows:
1. The contacts of the 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
VARI-MODE
CONNECTED COMPONENTS
oven lamp/turntable 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 3.4 volts
A.C. output on the filament winding, and approximately
2100 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
and primary interlock relay are activated with the following
results. The circuits to the oven lamp, turntable motor,
the cooling fan motor, and the high voltage components
are de-energized, and the digital read-out 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
DISPLAY
ON TIME
OFF TIME
100% power
P-HI
32 sec.
0 sec.
approx. 90% power
P-90
30 sec.
2 sec.
approx. 80% power
P-80
26 sec.
6 sec.
approx. 70% power
P-70
24 sec.
8 sec.
approx. 60% power
P-60
22 sec.
10 sec.
approx. 50% power
P-50
18 sec.
14 sec.
approx. 40% power
P-40
16 sec.
16 sec.
approx. 30% power
P-30
12 sec.
20 sec.
approx. 20% power
P-20
8 sec.
24 sec.
approx. 10% power
P-10
6 sec.
26 sec.
P-0
0 sec.
32 sec.
0% power
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.
POWER OUTPUT REDUCTION
If the oven is set for more than 20 minutes at 80, 90 or 100%
power level, after the first 20 minutes the power level will
automatically adjust itself to 70% power to avoid overcooking.
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R-204EWA
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED
2. CLOCK APPEARS ON DISPLAY
C/T FUSE
NOTE: " " indicates components with potential above 250V.
MAGNETRON
THERMAL CUT-OUT
COM.
POWER
TRANSFORMER
N.O.
(RY-2)
(RY-1)
A3
PRIMARY
INTERLOCK
RELAY
CAPACITOR
0.86µF
CONTROL UNIT
A1
B1
B2
DOOR
SENSING
SWITCH
TTM
OL
MONITOR
SWITCH
FM
TURNTABLE
MOTOR
OVEN
LAMP
MAGNETRON
GRN
120V AC
60 Hz
RECTIFIER
FAN
MOTOR
SECONDARY
INTERLOCK
SWITCH
Figure O-1. Oven Schematic-Off Condition
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED
2. COOKING TIME PROGRAMMED
3. VARIABLE COOKING CONTROL "HIGH"
4. "START" PAD TOUCHED
C/T FUSE
MAGNETRON
THERMAL CUT-OUT
COM.
POWER
TRANSFORMER
N.O.
(RY-2)
(RY-1)
A3
PRIMARY
INTERLOCK
RELAY
CAPACITOR
0.86µF
CONTROL UNIT
A1
B1
B2
DOOR
SENSING
SWITCH
TTM
OL
OVEN
LAMP
TURNTABLE
MOTOR
FM
MAGNETRON
GRN
120V AC
60 Hz
MONITOR
SWITCH
RECTIFIER
FAN
MOTOR
SECONDARY
INTERLOCK
SWITCH
Figure O-2. Oven Schematic-Cooking Condition
7
R-204EWA
DESCRIPTION AND FUNCTION OF COMPONENTS
DOOR OPEN MECHANISM
ARY INTERLOCK SWITCH AND MONITOR
SWITCH FOR PROPER OPERATION. (REFER TO CHAPTER "TEST PROCEDURE").
NOTE: C/T FUSE AND MONITOR SWITCH ARE
REPLACED AS AN ASSEMBLY
The door is opened by pulling the door, refer to the Figure
D-1.
Latch Heads
Latch Hook
TURNTABLE MOTOR
The turntable motor rotates the turntable located on the
bottom of the oven cavity, so that the food on the turntable
is cooked evenly. The turntable may turn in either direction.
Door
Sensing
Switch
Door
Secondary
Interlock
Switch
COOLING FAN MOTOR
Monitor
Switch
The cooling fan motor drives a blade which draws external
cool air. This cool air is directed through the air vents
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.
Figure D-1. Door Open Mechanism
DOOR SENSING AND SECONDARY INTERLOCK
SWITCHES
The secondary interlock switch is mounted in the lower
position of the latch hook and the door sensing switch in the
primary interlock system is mounted 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
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.
The thermal cut-out located on the top of the oven cavity is
designed to prevent damage to the magnetron if an over
heated condition develops in the tube due to cooling fan
failure, obstructed air guide, dirty or blocked air intake, etc.
Under normal operation, the thermal cut-out remains closed.
However, when abnormally high temperatures are reached
within the magnetron, the thermal cut-out will open at 257˚F
(125˚C), causing the oven to shut down.
MONITOR SWITCH
C/T FUSE
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 C/T fuse, when the contacts of the primary
interlock relay (RY2) and secondary interlock switch fail to
open when the door is opened.
1. The C/T fuse blows when the contacts (COM-NO) of the
primary interlock relay (RY2) 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 C/T fuse blows to prevent an electric shock
or fire hazard.
3. The C/T fuse, located on the top of the oven cavity, is
designed to prevent damage to the oven by fire. If the
food load is overcooked, by either error in cook time or
defect in the timer, the C/T fuse will open.
Under normal operation, the C/T fuse remains closed.
However, when abnormally high temperatures are reached
within the oven cavity, the C/T fuse will open at 248˚F
(120˚C), causing the oven to shut down or when the electric
currents beyond 15A flow, the C/T fuse will open.
MAGNETRON THERMAL CUT-OUT
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 (RY2) and
secondary interlock switch are in the OFF condition
(contacts open) due to its 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 secondary interlock switch contacts close.
3. If the door is opened, and the primary interlock relay
(RY2) and the secondary interlock switch contact fail to
open, the C/T fuse blows simultaneously with closing of
the monitor switch contacts.
CAUTION: BEFORE REPLACING A BLOWN C/T FUSE,
TEST THE DOOR SENSING SWITCH, PRIMARY INTERLOCK RELAY (RY2), SECOND-
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R-204EWA
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 C/T fuse, check the monitor switch, primary
interlock relay (RY2), door sensing switch and secondary interlock switch before replacing the C/T fuse.
If C/T fuse is replaced, the monitor switch must also be replaced. Use part FFS-BA025WRKZ 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 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.
9
R-204EWA
CK = Check / RE = Replace
FOIL PATTERN ON PWB.
EXPRESS DEFROST/ COMPU DEFROST
KEY UNIT
DIRTY OVEN CAVITY
LOW VOLTAGE
WRONG OPERATION
CONTROL UNIT OR RELAY
TURNTABLE MOTOR
COOLING FAN MOTOR
OVEN LAMP OR SOCKET
C/T FUSE
MONITOR SWITCH
F G H RE RE CK I/K CK CK CK J M L
SECONDARY INTERLOCK SWITCH
PRIMARY INTERLOCK SYSTEM
MAGNETRON THERMAL CUT-OUT
HIGH VOLTAGE CAPACITOR
POWER TRANSFORMER
C D E F
H.V. RECTIFIER ASSEMBLY
MAGNETRON
PROBLEM
CONDITION
SHORT OR OPEN WIRING
POSSIBLE CAUSE
AND
DEFECTIVE PARTS
RE CK A B
SHORT IN POWER CORD
TEST PROCEDURE
Home fuse blows when power cord
is plugged into wall receptacle.
C/T fuse blows when power cord is
plugged into wall receptacle.
OFF
CONDITION
Any letters or indicators do not appear in display when power cord is
first plugged into wall outlet.
Display does not operate properly
when STOP/CLEAR key is touched.
(Buzzer should sound and time of
day should appear in display.)
C/T fuse blows when the door is
opened.
Fan motor does not operate. (All
other electric components function.)
Oven lamp does not light at all. (All
other electric components function.)
Turntable motor does not operate. (All
other electric components function.)
Oven does not go into cook cycle
when START pad is touched
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).
Oven does not cook properly when
programmed for Cooking Power 50%
mode. (Operates properly on Cooking Power 100% mode.)
Oven lamp, turntable motor and fan
motor do not operate.
Oven goes into EXPRESS DEFROST/COMPU DEFROST but food
is not defrosted well.
TEST PROCEDURES
PROCEDURE
LETTER
A
COMPONENT TEST
MAGNETRON ASSEMBLY 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.
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.
10
R-204EWA
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
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: 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 power P-HI (100%) 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 24.4
to 45.4˚F(13.6 to 25.2˚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 132 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
MEASURE THE FILAMENT AND HIGH VOLTAGE.)
11
R-204EWA
TEST PROCEDURES
PROCEDURE
LETTER
C
COMPONENT TEST
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 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.
MAGNETRON THERMAL CUT-OUT 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.
A continuity check across the thermal cut-out terminals should indicate a closed circuit. If the
temperature of the magnetron reaches approximately 257˚F(125˚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.
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.
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.
5. Reconnect all leads removed from components during testing.
12
R-204EWA
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.
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 (RY2)
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect two (2) wire leads from the male tab terminals of the Primary Interlock Relay. Check the
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.
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.
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.
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.
SCREW
DRIVER
MONITOR
SWITCH
OHMMETER
13
R-204EWA
TEST PROCEDURES
PROCEDURE
LETTER
H
COMPONENT TEST
BLOWN C/T 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 C/T 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 C/T fuse.
CAUTION: BEFORE REPLACING A BLOWN C/T FUSE, TEST THE PRIMARY INTERLOCK RELAY,
SECONDARY INTERLOCK SWITCH, DOOR SENSING SWITCH AND MONITOR SWITCH
FOR PROPER OPERATION.
If the C/T fuse is blown by improper switch operation, the C/T fuse and monitor switch must be
replaced with "C/T fuse and monitor switch assembly" part number FFS-BA025WRKZ, even if the
monitor switch operates normally. The C/T fuse and monitor switch assembly is comprised of a 15
ampere fuse and switch.
A continuity check across the C/T fuse terminals should indicate a closed circuit unless the temperature
of the C/T fuse reaches approximately 248˚F(120˚C).
An open C/T fuse indicates the oven overheated, Replace the oven C/T fuse and check the inside of the
oven cavity, the proper setting of cooking time and the proper operation of control unit. Also check for
proper air flow through the ovens venting system. Especially check the cooling fan for proper operation
and the air guide for restriction.
CAUTION: IF THE C/T FUSE INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE, REPLACE
THE C/T FUSE.
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
TOUCH CONTROL PANEL ASSEMBLY TEST
The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore,
unlike conventional microwave ovens, proper maintenance cannot be performed with only a voltmeter
and ohmmeter.
In this service manual, the touch control panel assembly is divided into two units, Control Unit and Key
Unit, and troubleshooting by unit replacement is described according to the symptoms indicated.
Before testing,
1) Disconnect the power supply cord and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Disconnect the leads to the primary of the power transformer.
5) Ensure that these leads remain isolated from other components and oven chassis by using
insulation tape.
1. Key Unit.
NOTE ;
1) Check key unit ribbon connection before replacement.
2) Reconnect all leads removed from components during testing.
3) Re-install the outer case (cabinet).
4) Reconnect the power supply cord after the outer case is installed.
5) Run the oven and check all functions.
The following symptoms indicate a defective key unit.
a) When touching the pads, a certain pad produces no signal at all.
b) When touching a number pad, two figures or more are displayed.
c) When touching the pads, sometimes a pad produces no signal.
If the key unit is defective.
1) Disconnect the power supply cord and then remove outer case.
14
R-204EWA
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Replace the key unit.
5) Reconnect all leads removed from components during testing.
6) Re-install the outer case (cabinet).
7) Reconnect the power supply cord after the outer case is installed.
8) Run the oven and check all functions.
2. Control Unit.
The following symptoms indicate a defective control unit. Before replacing the control unit, perform
the Key unit test (Procedure J) to determine if control unit is faulty.
2-1 In connection with pads.
a) When touching the pads, a certain group of pads do not produce a signal.
b) When touching the pads, no pads produce a signal.
2-2 In connection with indicators
a) At a certain digit, all or some segments do not light up.
b) At a certain digit, brightness is low.
c) Only one indicator does not light.
d) The corresponding segments of all digits do not light up; or they continue to light up.
e) Wrong figure appears.
f) A certain group of indicators do not light up.
g) The figure of all digits flicker.
2-3 Other possible problems caused by defective control unit.
a) Buzzer does not sound or continues to sound.
b) Clock does not operate properly.
c) Cooking is not possible.
When testing is completed,
1) Disconnect the power supply cord and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Reconnect all leads removed from components during testing.
5) Re-install the outer case (cabinet).
6) Reconnect the power supply cord after the outer case is installed.
7) Run the oven and check all functions.
J
KEY UNIT TEST
1.
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.
If the display fails to clear when the STOP/CLEAR pad is depressed, first verify the flat ribbon cable
is making good contact, verify that the door sensing switch (stop switch) operates properly; that is the
contacts are closed when the door is closed and open when the door is open. If the door sensing
switch (stop switch) is good, disconnect the flat ribbon cable that connects the key unit to the control
unit and make sure the door sensing switch is closed (either close the door or short the door sensing
switch connector). Use the Key unit matrix indicated on the control panel schematic and place a
jumper wire between the pins that correspond to the STOP/CLEAR pad making momentary contact.
If the control unit responds by clearing with a beep the key unit is faulty and must be replaced. If the
control unit does not respond, it is faulty and must be replaced. If a specific pad does not respond,
the above method may be used (after clearing the control unit) to determine if the control unit or key
pad is at fault.
Reconnect all leads removed from components during testing.
Re-install the outer case (cabinet).
Reconnect the power supply cord after the outer case is installed.
Run the oven and check all functions.
15
R-204EWA
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
G6
G5
G4
G3
G2
G7
BEVERAGE
6
2
DINNER
PLATE
MINUTE
PLUS
G8
FRESH
VEGETABLES
3
5
4
EXPRESS
DEFROST
POWER
LEVEL
G9
ROLLS &
MUFFINS
TIMER
CLOCK
0
1
BAKED
POTATOES
STOP
CLEAR
9
8
7
POPCORN
START
G10
K
G1
RELAY TEST
1.
2.
3.
4.
5.
6.
7.
Disconnect the power supply cord and then remove outer case.
Open the door and blocked it open.
Discharge high voltage capacitor.
Disconnect the leads to the primary of the power transformer.
Ensure that these leads remain isolated from other components and oven chassis by using insulation tape.
After that procedure, re-connect the power supply cord.
Remove the outer case and check voltage between Pin No. 3 of the 2 pin connector (A) and the
common terminal of the relay RY2 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. -13.5V D.C.
Oven lamp / Turntable motor / Cooling fan motor
RY2
Approx. -12.5V D.C.
Power transformer
8. Disconnect the power supply cord and then remove outer case.
9. Open the door and block it open.
10. Discharge high voltage capacitor.
11. Reconnect all leads removed from components during testing.
12. Re-install the outer case (cabinet).
13. Reconnect the power supply cord after the outer case is installed.
14. Run the oven and check all functions.
L
EXPRESS DEFROST TEST
(1) Place one cup of water in the center of the turntable tray in the oven cavity.
(2) Close the door, touch the " EXPRESS DEFROST " pad once for 0.5lbs in weight.
(3) The oven is in Express Defrost cooking condition.
(4) The oven will operate as follows.
MENU
EXPRESS DEFROST
0.5lb
1ST STAGE
2ND STAGE
3RD STAGE
4TH STAGE
LEVEL
TIME
LEVEL
TIME
LEVEL
TIME
LEVEL
TIME
70%
57sec.
0%
57sec.
50%
32sec.
30%
45sec.
(5) If improper operation is indicated, the control unit is probably defective and should be checked.
M
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.
16
R-204EWA
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
1. Foil pattern check and repairs.
1) Disconnect the power supply cord and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Follow the troubleshooting guide given below for repair.
STEPS
OCCURRENCE
CAUSE OR CORRECTION
1
Only pattern at "a" is broken.
*Insert jumper wire J1 and solder.
2
Pattern at "a" and "b" are broken.
*Insert the coil RCILF2003YAZZ between "c" and "d".
c
b
(J1)
RY1
d
1
5) Make a visual inspection of the varistor.
Check for burned damage and examine the
transformer with a tester for the presence of
layer short-circuit (check the primary coil
resistance which is approximately 563Ω ±
10%). If any abnormal condition is detected,
replace the control unit.
a
P
6) Reconnect all leads removed from
components during testing.
RY2
7) Re-install the outer case (cabinet).
8) Reconnect the power supply cord after the outer case is installed.
9) Run the oven and check all functions.
2. Follow the troubleshooting guide given below, if indicator does not light up after above check and
repairs are finished.
1) Disconnect the power supply cord and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Disconnect the leads to the primary of the power transformer.
5) Ensure that these leads remain isolated from other components and oven chassis by using
insulation tape.
6) After that procedure, re-connect the power supply cord.
7) Follow the troubleshooting guide given below for repair.
STEPS
OCCURRENCE
CAUSE OR CORRECTION
1
The rated AC voltage is not present between
Pin No. 3 of the 2-pin connector (A) and the
common terminal of the relay RY2.
Check supply voltage and oven power cord.
2
The rated AC voltage is present at primary
side of low voltage transformer.
Low voltage transformer or secondary circuit defective.
Check and replace.
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.
17
R-204EWA
TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOUCH CONTROL PANEL
3) Power Source Circuit
This circuit generates voltage necessary in the control
unit from the AC line voltage. In addition, the synchronizing
signal is available in order to compose a basic standard
time in the clock circuit.
The touch control section consists of the following units as
shown in the touch control panel circuit.
(1) Key Unit
(2) Control Unit
Symbol
VC
The principal functions of these units and their related
signals are explained below.
Voltage
-5V
Application
LSI(IC1)
Key Unit
The key unit is composed of a matrix, signals generated in
the LSI are sent to the key unit through R00, R01, R03, R20
and R21.
When a key pad is touched, a signal is completed through
the key unit and passed back to the LSI through R23, K00,
K01 and K02 to perform the function that was requested.
4) Relay Circuit
To drive the magnetron, fan motor, turntable motor and
light the oven lamp.
Control Unit
Control unit consists of LSI, ACL circuit, indicator circuit,
power source circuit, relay circuit, buzzer circuit and synchronizing signal circuit.
6) 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.
5) Buzzer Circuit
The buzzer is responsive to signals from the LSI to emit
audible sounds (key touch sound and completion sound).
1) ACL
This circuit generates a signal which resets the LSI to the
initial state when power is supplied.
7) Door Sensing Switch
A switch to "tell" the LSI if the door is open or closed.
2) Indicator Circuit
This circuit consists of 4-digits, 12-segments and 3common electrodes using a Liquid Crystal Display.
18
R-204EWA
DESCRIPTION OF LSI
The I/O signal of the LSI are detailed in the following table.
Pin No.
Signal
I/O
1
RESET
IN
2
3
TEST
VSS
IN
IN
4
OCS3
IN
5
OCS4
OUT
6
7
VD1
VDD
IN
IN
8
AVDD
IN
9
AVREF
IN
10
AVSS
IN
P40-P42
IN
14
P43
IN
15
BZ
OUT
11-13
Description
Auto clear terminal.
Signal is input to reset the LSI to the initial state when power is supplied. Temporarily
set to “L” level the moment power is supplied, at this time the LSI is reset. Thereafter
set at “H” level.
Connected to GND.
Power source voltage: -5V.
VSS voltage of power source circuit input. Connected to VC.
Internal clock oscillation frequency setting input.
The internal clock frequency is set by inserting the resistor oscillation circuit with
respect to OCS4 terminal.
Internal clock oscillation frequency control output.
Output to control oscillation input of OCS3.
Power source for oscillation circuit.
Power source voltage input terminal.
Connected to GND.
A/D converter power source voltage.
The power source voltage to drive the A/D converter in the LSI. Connected to GND.
A/D converter power source voltage.
The power source voltage to drive the A/D converter in the LSI. Connected to GND.
Power source voltage: -5V.
AVSS voltage of power source circuit input. Connected to VC.
Terminal to change functions according to the Model.
By using the A/D converter contained in the LSI, DC voltage in accordance with the
Model in operation is applied to set up its function.
To input signal which communicates the door open/close information to LSI.
Door close “H” level signal (0V). Door open “L” level (-5V).
0.1 sec.
Signal to sound buzzer (2.0 kHz).
H : GND
A
A: key touch sound.
L : -5V
B: Completion sound.
2.0 sec.
H : GND
B
L : -5V
16
R00
OUT
17
R01
OUT
18
R02
OUT
19
R03
OUT
20
P20
OUT
21
P21
OUT
22
P22
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P23, K00, K01 and K02
terminal while one of G6 line keys on key matrix is touched.
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P23, K00, K01 and K02
terminal while one of G5 line keys on key matrix is touched.
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P23, K00, K01 and K02
terminal while one of G4 line keys on key matrix is touched.
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P23, K00, K01 and K02
terminal while one of G3 line keys on key matrix is touched.
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P23, K00, K01 and K02
terminal while one of G2 line keys on key matrix is touched.
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P23, K00, K01 and K02
terminal while one of G1 line keys on key matrix is touched.
Terminal not used.
19
R-204EWA
Pin No.
23
Signal
P23
I/O
IN
24
K00
IN
25
K01
IN
26
K02
IN
27
K03
IN
Description
Signal similar to K02.
When either G7 line on key matrix is touched, a corresponding signal will be input into P23.
Signal similar to K02.
When either G8 line on key matrix is touched, a corresponding signal will be input into K00.
Signal similar to K02.
When either G9 line on key matrix is touched, a corresponding signal will be input into K01.
Signal coming from touch key.
When either G10 line on key matrix is touched, a corresponding signal out of R00, R01,
R02, R03, P20 and P21 will be input into K02. When no key is touched, the signal is
held at “H” level.
Signal synchronized with commercial power source frequency.
This is the basic timing for time processing of
GND
LSI.
-5V
16.7 msec.
28
COM0
OUT
29
COM1
OUT
30
COM2
OUT
COM3
OUT
OUT
OUT
31
32-33
34
35
36
SEG0-SEG1
SEG2
SEG3
SEG4
OUT
OUT
Common data signal: COM1.
Connected to LCD (Pin No. C1)
Common data signal: COM2.
Connected to LCD (Pin No. C2)
Common data signal: COM1.
Connected to LCD (Pin No. C3)
Terminal not used.
Terminal not used.
Magnetron high-voltage circuit driving signal.
OFF
To turn on and off the cook relay (RY2). The
signals holds “L” level during microwave cook100P
ON
ing and “H” level while not cooking. In other
OFF
cooking modes (variable cooking) the signal
24 sec.
70P
turns to “H” level and “L” level in repetition
ON
according to the power level.
Terminal not used.
Oven lamp, fan motor and turntable motor driving signal.
H : GND
L : -5V
OFF
H : GND
8 sec.
L : -5V
16.7 msec.
To turn on and off shut off relay (RY1). The
square waveform voltage is delivered to the
RY1 driving circuit and RY2 control circuit.
37-39
40-51
SEG5-SEG7
SEG8-SEG19
OUT
OUT
52-53
VC1-VC2
IN
VC3
OUT
54
H : GND
L : -5V
During cooking
Terminal not used.
Segment data signal.
Connected to LCD.
The relation between signals are as follows:
LSI signal (Pin No.)
LCD segment LSI signal (Pin No.) LCD segment
SEG 8 (40) .......................... S12
SEG 14 (46) ........................... S6
SEG 9 (41) .......................... S11
SEG 15 (47) ........................... S5
SEG 10 (42) .......................... S10
SEG 16 (48) ........................... S4
SEG 11 (43) ............................ S9
SEG 17 (49) ........................... S3
SEG 12 (44) ............................ S8
SEG 18 (50) ........................... S2
SEG 13 (45) ............................ S7
SEG 19 (51) ........................... S1
Power source voltage input terminal.
Standard voltage for LCD.
Terminal not used.
20
R-204EWA
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.
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. 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).
5) Re-connect the power supply cord after the outer case
is installed.
6) Run the oven and check all function.
3. 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
4. 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.
21
R-204EWA
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.
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 PANAL PARTS, DOOR PARTS’, when carrying out any of
the following removal procedures:
OUTER CASE REMOVAL
To remove the outer case, procedure as follows.
1. Disconnect the power supply cord.
2. Open the oven door and block it open.
3. Remove the two (2) screws from the lower portion of the
rear cabinet using a T20H Torx type or GTXH20-100
screw driver.
4. Remove the remaining two (2) screws from rear and four
(4) screws along the right and left side of outer case.
5. Slide the entire outer case back out about 1 inch (3 cm)
to free it from retaining clips on the cavity face plate.
6. Lift entire outer case from the unit.
Special Screw
Screw Driver
Type: TORX T20 H or
GTXH20-100
Figure C-1. Outer case removal
22
R-204EWA
CAUTION: 1. DISCONNECT OVEN FROM POWER SUPPLY BEFORE REMOVING OUTER CASE.
2. DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN
COMPONENTS OR WIRING.
NOTE: When replacing the outer case, the 2 special
Torx screws must be reinstalled in the same
locations.
MAGNETRON REMOVAL
1.
2.
3.
4.
5.
6. Remove the magnetron from waveguide.
7. Now, the magnetron is free.
CAUTION: WHEN REPLACING THE MAGNETRON, BE
SURE THE R.F. GASKET IS IN PLACE AND
THE MAGNETRON MOUNTING SCREWS
ARE TIGHTENED SECURELY.
Disconnect the power supply cord and remove outer case.
Open the oven door and block it open.
Discharge high voltage capacitor.
Disconnect the wire leads from magnetron.
Remove the three (3) screws holding the magnetron to
the waveguide.
HIGH VOLTAGE COMPONENTS REMOVAL
(HIGH VOLTAGE CAPACITOR AND HIGH VOLTAGE RECTIFIER ASSEMBLY)
8. Disconnect all the leads and terminals of high voltage
rectifier assembly from high voltage capacitor.
9. Now the H.V. rectifier assembly and H.V. capacitor
should be free.
CAUTION: WHEN REPLACING HIGH VOLTAGE RECTIFIER ASSEMBLY, ENSURE THAT THE CATHODE (GROUND) CONNECTION IS SECURELY FIXED TO THE CAPACITOR
HOLDER WITH A GROUNDING SCREW.
CAUTION: DO NOT REPLACE ONLY HIGH VOLTAGE
RECTIFIER. WHEN REPLACING IT, REPLACE HIGH VOLTAGE RECTIFIER ASSEMBLY.
To remove the components, proceed as follows.
1. Disconnect the power supply cord and remove outer case.
2. Open the oven door and block it open.
3. Discharge high voltage capacitor.
4. Remove one (1) screw holding capacitor holder to rear
cabinet.
5. Disconnect the H.V. wire of the H.V. rectifier assembly
from the magnetron.
6. Disconnect the filament lead of the power transformer
from the H.V. capacitor.
7. Remove one (1) screw holding ground side terminal of
high voltage rectifier assembly, and remove capacitor
holder.
POWER TRANSFORMER REMOVAL
10.Now the power transformer is free.
Re-install
1. Rest transformer on the bottom plate with its primary
terminals toward the oven face plate.
2. Secure transformer with two (2) screws to the bottom
plate from above.
3. Secure transformer with two (2) screws to the bottom
plate from below.
4. Re-connect wire leads (primary and high voltage) and
filament leads to the power transformer, magnetron and
high voltage capacitor, referring to "Pictorial Diagram".
5. Re-install outer case and check that the oven is operating
properly.
1. Disconnect the power supply cord and remove outer
case.
2. Open the oven door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the wire leads (main wire harness and H.V.
wire) from power transformer.
5. Disconnect the lead from magnetron filament.
6. Disconnect the lead of the power transformer from high
voltage capacitor.
7. Remove the two (2) screws holding the transformer to
bottom plate from below.
8. Remove the two (2) screws holding the transformer to
bottom plate from above.
9. Remove the transformer.
POSITIVE LOCK® CONNECTOR (NO-CASE TYPE) REMOVAL
Terminal
1.
2.
3.
4.
5.
Disconnect the power supply cord, and remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
Push the lever of positive lock® connector.
Pull down on the positive lock® connector.
CAUTION: WHEN CONNECTING THE POSITIVE LOCK®
CONNECTORS TO THE TERMINALS, INSTALL THE POSITIVE LOCK® SO THAT THE
LEVER FACES YOU.
Positive lock®
connector
1
Push
Lever
2
Figure C-2. Positive lock® connector
23
Pull down
R-204EWA
CONTROL PANEL ASSEMBLY REMOVAL
1.
2.
3.
4.
5.
Disconnect the power supply cord and remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
Disconnect the leads from the control unit.
Remove the one (1) screw holding the chassis support
to the front plate of the oven cavity.
6. Remove the chassis support from the oven.
7. Lift up the control panel and release it from the oven
cavity.
8. Now, the control panel assembly is free.
NOTE: 1. Before attaching a new key unit, remove remaining
adhesive on the control panel frame surfaces
completely with alcohol.
2. When attaching the key unit to the control panel
frame, adjust the upper edge and right edge of
the key unit to the correct position of control panel
frame.
3. Stick the key unit firmly to the control panel frame
by rubbing with soft cloth not to scratch.
TURNTABLE MOTOR REMOVAL
Removal
8. Remove the turntable motor from the oven cavity.
9. Remove the O-ring and washer from the turntable motor.
10.Now, the turntable motor is free.
1. Disconnect the power supply cord.
2. Remove the turntable and turntable support from the
oven cavity.
3. Turn the oven over.
4. Cut the four (4) bridges holding the turntable motor cover
to the bottom plate with the cutting pliers as shown in
Figure C-3.
Reinstallation
1. Remove the any sharp edges on the turntable motor
cover and the bottom plate with the cutting pliers.
2. Re-install the O-ring.
3. Apply the grease (Shinetsu silicone grease G-420 of
Sinetsu Chemical Co. Ltd. or Toray Silicone grease SH14 of Toray Silicone Co., Ltd.) to the O-ring and the base
of the turntable motor shaft as shown in Figure C-4.
4. Re-install the turntable motor with the O-ring and washer
to the oven cavity with the single (1) screw.
5. Re-connect the wire leads to the turntable motor.
6. Insert the tab of the turntable motor cover into the hole of
the bottom plate as shown in Figure C-3.
7. Re-install the turntable motor cover to the bottom plate
with one (1) screw XHTSD40P08RV0 or
XFPSD40P08K00 as shown in Figure C-3.
CAUTION: DO NOT DROP THE TURNTABLE MOTOR
COVER INTO THE OVEN AFTER CUTTING
THE BRIDGES. BECAUSE IT WILL DAMAGE
THE WIRE LEADS OF THE MOTOR AND IT IS
DIFFICULT TO REMOVE IT OUT OF THE
OVEN.
5. Remove the turntable motor cover from the bottom plate.
6. Disconnect the wire leads from the turntable motor.
7. Remove the single (1) screw holding the turntable motor
to the oven cavity.
Screw; XHTSD40P08RV0 or
XFPSD40P08K00
Cutting Pliers
Turnrable
Bridges
Motor Cover
Tab
Washer
O-ring
Hole
Apply the
grease hear
Base of turntable
motor shaft
Washer
O-ring
Turntable motor
Bottom Plate
Figure C-4. Washer and O-ring Installation and
Grease Applying.
Figure C-3. Turntable Motor Cover
COOLING FAN MOTOR REMOVAL
REMOVAL
1. Disconnect the power supply cord and 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 chassis support
to the oven cavity front plate.
6. Remove the chassis support .
7. Release the filament lead of the power transformer and
the H.V. wire from the fan duct.
8. Remove the one (1) screw holding the light mounting
plate to the oven cavity.
9. Release the wire leads (to the oven lamp) from the hole
of the fan duct.
10.Remove the one (1) screw holding the fan duct to the
waveguide flange.
11.Release the fan motor assembly from the oven cavity.
12.Remove the fan blade from the fan motor shaft according
to the following procedure.
13.Hold the edge of the rotor of the fan motor by using a pair
of groove joint pliers.
24
R-204EWA
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 damaged 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 damaged.
• Do not disfigure the bracket by pinching with
the pliers.
14.Remove the fan blade assembly from the shaft of the fan
motor by pulling and rotating the fan blade with your
hand.
15.Now, the fan blade will be free.
5. 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 strongly when installed
because the bracket may be transformed.
• Make sure that the fan blade rotates smooth after
installed.
• Make sure that the axis of the shaft is not slanted.
6. Install the fan motor assembly to the oven cavity by fitting
the tabs of the fan duct into the holes of the oven cavity
and the waveguide flange.
7. Hold the fan duct to the waveguide flange with the one (1)
screw.
8. Re-install the light mounting plate to the oven cavity with
the one (1) screw.
9. Insert the end of the chassis support into the slit of the
oven cavity rear cabinet.
10.Re-install the chassis support to the oven cavity front
plate with the one (1) screw.
11.Install the filament lead and the H.V. wire into the hole of
the fan duct .
12.Re-install the wire leads (to the oven lamp) to the hole of
the fan duct.
13.Connect the wire leads to the fan motor, referring to the
pictorial diagram.
CAUTION:
• Do not re-use the removed fan blade because
the hole (for shaft) may be larger than normal.
16.Remove the two (2) screws holding the fan motor to the
fan duct.
17.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.
4. Apply the screw lock tight into the hole (for shaft) of the
fan blade.
Shaft
Coil
Groove joint pliers
Table
Shaft
Axis
Stator
Gap
Bracket
Rotor
Stator
These are the positions
that should be pinched
with pliers
Center of
bracket
Rotor
Rear View
Side View
DOOR SENSING SWITCH, SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH REMOVAL
8-2. Then pull out the switch while pushing the plunger of the
switch again.
8-3. Now the secondary interlock switch is free.
9. To remove the monitor switch or door sensing switch.
9-1. Push outward on the tab that is holding the switch, and
turn the switch so that the pole is an axis.
9-2. Pull out the switch from the latch hook. Do not break the
pole or tab of the latch hook.
9-3. Now the switch is free.
Disconnect the power supply cord and remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
Disconnect wire leads from the switches and control
panel.
5. Remove the control panel assembly from the oven cavity
front flange. Refer to chapter "CONTROL PANEL
ASSEMBLY REMOVAL"
6. Remove two (2) screws holding latch hook to oven
flange.
7. Remove latch hook assembly from oven flange.
8. To remove the secondary interlock switch.
8-1. Pull out the secondary interlock switch from the latch
hook, by pushing outward on the tab that is holding the
switch. But the switch will be caught by the bar of the
latch hook.
1.
2.
3.
4.
Reinstallation
1. Re-install each switch in its place. The secondary interlock
switch is in the lower position and the monitor switch is
in the middle position. The door sensing switch is in the
upper position.
2. Re-connect wire leads to each switch. Refer to chapter
"Pictorial Diagram".
25
R-204EWA
3. Secure latch hook (with two (2) mounting screws) to
oven flange.
4. Re-install the control panel assembly to the oven cavity
front flange.
5. Re-connect wire leads to the control unit. Refer to
chapter "Pictorial Diagram".
6. Make sure that monitor switch is operating properly and
check continuity of the monitor circuit. Refer to chapter
"Test Procedure", and Adjustment Procedure below.
Latch Hook
Door
Sensing
Switch
Pole
ard
tw
Ou
Pole
Monitor
Switch
Tab
Secondary
Interlock
Switch
Tab
Bar
Ou
twa
rd
Figure C-5. Latch Switch Removal
DOOR SENSING SWITCH, SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH ADJUSTMENT
toward the oven face. Then check lower portion of the
latch hook, pushing and pulling lower portion of door
toward the oven face. Both results (play in the door)
should be less than 0.5mm.
2. The contacts of door sensing switch and secondary
interlock switch open within 1.6mm gap between right
side of cavity face plate and door when door is open.
3. The monitor switch contacts close when the door is
opened.
4. Re-install outer case and check for microwave leakage
around the door with an approved microwave survey
meter. (Refer to Microwave Measurement Procedure.)
1. Disconnect the power supply cord and 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
flange of the oven front face.
5. With the 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 horizontal position of
the latch hook should be adjusted so that the monitor
switch is activated with the door closed. The vertical
position of the latch hook should be adjusted so that the
door sensing switch and the secondary interlock switch
are activated with the door closed.
6. Secure the screws 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.
Latch Heads
Latch Hook
Door
Sensing
Switch
After adjustment, make sure of the following.
1. In and out play of the 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
Door
Monitor
Switch
Secondary
Interlock
Switch
Figure C-6. Latch Switch Adjustments
DOOR REPLACEMENT
9
REMOVAL
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 corner portion of door
panel as shown in Figure C-7 to free engaging parts.
4. Pry the choke cover by inserting a putty knife in order
shown in figure C-7.
5. Release choke cover from door panel.
6. Now choke cover is free.
NOTE: When carrying out any repair to the door, do not
bend or warp the slit choke (tabs on the door
panel assembly) to prevent microwave leakage.
Choke Cover
7
w
2
6
0
q
8
1
54 3
Putty Knife
Door Frame
Figure C-7. Door Disassembly
7. Release two (2) pins of door panel from two (2) holes of
26
R-204EWA
upper and lower oven hinges by lifting up.
8. Now, door panel is free from oven cavity.
9. Release door panel from ten (10) tabs of door frame and
remove door frame by sliding the door panel downward.
10.Now, door panel with sealer film is free.
11.Tear sealer film from door panel.
12.Now, door panel is free.
13.Slide latch head upward and remove it from door frame
with releasing latch spring from door frame and latch
head.
14.Now, latch head and latch spring are free.
15.Remove door screen from door frame.
16.Now, door screen is free.
Therefore, occasional appearance of moisture, light
or sensing of gentle warm air movement around
oven door is not abnormal and do not of themselves,
indicate a leakage of microwave energy from oven
cavity.
Upper
Pin Oven
Hinge
Upper Oven
Hinge
Door Panel
Slit Choke of
Door Panel
REINSTALLATION
1. Re-install door screen to door frame.
2. Re-install latch spring to the head. Re-install latch spring
to the door frame. Re-install latch head to the door frame.
3. Re-install door panel to door frame by fitting ten (10) tabs
of door frame to ten (10) holes of door panel.
4. Put sealer film on door panel. Refer to "Sealer Film" and
figure C-9, on how to handle the new film.
5. Catch two (2) pins of door panel on two (2) hole of upper
and lower oven hinges.
6. Re-install choke cover to door panel by pushing.
Note: After any service to the door;
(A) Make sure that door sensing switch, secondary
interlock switch and monitor 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.
Lower Oven
Hinge
Choke Cover
Lower
Pin Oven
Hinge
Figure C-8. Door Replacement
SEALER FILM
Installation
1. Put the adhesive tape on the backing film of the sealer
film as shown in Fig. C-9.
2. Tear the backing film by pulling the adhesive tape.
3. Put the pasted side of the sealer film on the door panel.
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:
Sealer film
Backing film
Adhesive tape
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 door be airtight, moisture (condensation)-tight or light-tight.
Figure C-9. Sealer film
27
H
1
2
1
3
28
3
ORG
ORG
RED
CN-A
1 ORG
2
3 WHT
4
GRY
WHT
WHT
WHT
SECONDARY
INTERLOCK SWITCH
COM
N.O.
COM
GRY
GRY
GRY
5
WHT
GRY
ORG
ORG
N
H.V.
RECTIFIER
POWER
TRANSFORMER
HIGH VOLTAGE
WIRE B
MAGNETRON
HIGH
VOLTAGE
CAPACITOR
HIGH VOLTAGE COMPONENTS
BLK
MAGNETRON
THERMAL CUT-OUT
NOTE:
The neutral (WHT) wire must be
connected to the terminal with "N"
mark on the power supply cord.
POWER SUPPLY CORD
120V 60Hz
4
5
Figure S-1. Pictorial Diagram
TURNTABLE
MOTOR
ORG
ORG
ORG
RED
WHT
GRY
RED
WHT
3
MONITOR
SWITCH
N.C.
RED
FAN MOTOR
D
CN-A
GRY
GRN
GRD
2
RY2
CN-B
1 GRY
2 GRN
COM
N.O.
WHT
RED
Blue Mark
C
RY1
1
CN-B
SP1
DOOR
SENSING SWITCH
F
GRN
GRN
NOTE: Hot (RED) wire must
be connected to the terminal
with blue mark on the oven
light socket.
RED
A
2
CONTROL UNIT
G
To chassis support
BLK
B
NOTE:
The grounding conductor of
the power supply cord has
been grounded by power
supply cord fixing screw.
The screw must always be
kept tight.
1
H
E
C/T FUSE
R-204EWA
6
A
B
C
6
D
E
F
G
H
3
29
4
DOOR
SENSING
SWITCH
B1
B2
COM
NO
A1
c
d
RY2
RY1
C1 0.1µ/50v
C2 470µ/25v
3.3k 1/4w
R30
SP1
PKM22EPT
Q20
DTA143EKA
5
R5
1k
ZD1
HZ4C3
R73 15k
R72 15k
R71 15k
R70 15k
(J12) 7.5k
(J10)
(J14)
(J13) 10k
(J15) 4.7k C7
0.1µ
(J11) 4.7k /25v
54
14
P43
P42
P41
P40
15
AVSS
AVREF
AVDD
VDD
VD1
OCS4
OCS3
RESET
TEST
VSS
1
R02
G10
G9
G8
G7
IC1
P20
G6
2
KEY UNIT
9
8
0
5
G4
6
30
COM2
COM3
SEG0
SEG1
SEG2
SEG3
SEG4
SEG5
SEG6
SEG7
SEG8
SEG9
SEG10
S12
S11
S9
S8
G3
G2
G1
7
POPCORN START
DINNER MINUTE
PLATE
PLUS
EXPRESS POWER
4
DEFROST LEVEL
STOP
BAKED
1
POTATO CLEAR
R65
15k
G5
FRESH
3
VEGETABLES
ROLL & TIMER
MUFFIN CLOCK
BEVERAGE
29
44
SEG11
SEG12
45
5
Figure S-2. Control Panel Circuit
: IF NOT SPECIFIED, 1/10W ± 5%
: IF NOT SPECIFIED, 1SS270A
R41 15k
C20
0.1µ
/25v
Q30 DTA143EKA
Q10 DTA143EKA
VC
C6
0.1µ/25v
C5 0.1µ/25v
4
NOTE
D40
D22
C8 220µ/10v
C21 10µ/35v
Q22
KRA105M
–
+
R4
910 1/2w
Q21
DTD143ES
VR
C3 0.01µ/25v
C11 0.01µ/25v
VRS1 10G471K
b
R78 220k
R10 15k
R20 15k
Q1
2SA1037AK
R77 220k
SEG19
ON DEF. LBS QTY. CHECK
3
GND
AC(H)
MICRO
OVEN LAMP
TURNTABLE
MOTOR
FAN MOTOR
a
D20
D21
R50 20kF
0.01µ
/25v
R6 15k
C4
R76 220k
C10
0.1µ
/25v
R40 4.7k
–
VC3
BZ
+
VC2
R00
–
VC1
R01
+
P21
D4
P22
D2
SEG18
GND
SEG15
GND
S10
D3
S5
D1
SEG17
K00
AC120V
60Hz
SEG14
A3
S7
S6
R64
15k
AC(N)
C40 0.01µ/25v
SEG16
K01
2
K02
H
P23
G
R75 220k
2
R67
15k
D
SEG13
LIQUID CRYSTAL DISPLAY
S4
CPU UNIT
S3
S2
POWER UNIT
S1
D1-D4 :
1N4002
C1
1
R63
15k
F
C2
C3
E
R62
15k
C
K03
B
COM0
A
COM1
1
R66
15k
T1
R-204EWA
6
A
B
C
6
D
E
F
G
H
R03
(J1)
R-204EWA
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
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
AH
AS
AN
AP
BH
AQ
AQ
AQ
AU
AT
AW
AV
AU
BL
BE
AL
AW
AS
AK
1
1
2
AY
AF
AC
1
1
1
1
1
3
BL
BC
AZ
AM
AE
AA
1
1
2
1
1
1
1
1
1
1
1
1
1
2
1
1
1
AL
AP
AD
AF
AL
AG
-AD
AE
AG
AM
AH
AH
AE
AN
AG
AC
1
1
1
1
1
1
1
4
AT
AY
AS
AE
AB
AG
AK
AA
1
1
1
1
AP
AN
AN
AH
ELECTRIC PARTS
*
*
*
*
*
*
*
*∆
*∆
1- 1
1- 2
1- 3
1- 3
1- 4
1- 5
1- 5
1- 5
1- 6
1- 6
1- 6
1- 7
1- 7
1- 8
1- 8
1- 9
1-10
1-10
1-11
QSW-MA137WRE0
FFS-BA025WRKZ
FACCDA086WREZ
FACCDA081WRE0
RTRN-A646WRZZ
FH-DZA087WRK0
FH-DZA081WRK0
FH-DZA082WRK0
RC-QZA284WRZZ
RC-QZA228WRE0
RC-QZA201WRE0
RMOTEA383WRE0
RMOTEA355WRE0
RV-MZA306WRZZ
RV-MZA226WRE0
RLMPTA082WRZZ
RMOTDA186WRE0
RMOTDA211WRE0
RTHM-A116WRE0
Secondary interlock switch & door sensing switch
C/T fuse & monitor switch(AM51620C53Y1) assembly
Power supply cord
Power supply cord (Interchangeable)
Power transformer
High voltage rectifier
High voltage rectifier (Interchangeable)
High voltage rectifier (Interchangeable)
High voltage capacitor
High voltage capacitor (Interchangeable)
High voltage capacitor (Interchangeable)
Fan motor
Fan motor (Interchangeable)
Magnetron
Magnetron (Interchangeable)
Oven lamp
Turntable motor
Turntable motor (Interchangeable)
Thermal cut-out 125˚C
2- 1
2- 2
2- 3
GCABUA696WRP0
GDAI-A304WRW0
GLEGPA074WRE0
Outer case cabinet
Bottom plate
Foot
CABINET PARTS
CONTROL PANEL PARTS
333333-
1
2
2-1
2-2
3
4
DPWBFC195WRUZ
FPNLCB569WRKZ
FUNTKB065WREZ
RLCDSA089DRZZ
QCNC-A013WRZZ
XEPSD30P08XS0
Control unit
Control panel frame with key unit and LCD
Key unit
Liquid crystal display
Rubber connector
Screw; 3mm x 8mm
PHOK-A105WRF0
LANGQA530WRWZ
PCUSUA502WRP0
LBNDKA038WRP0
NFANJA029WRE0
PDUC-A694WRF0
*************
GLEGPA073WRF0
LANGTA318WRP0
PCUSGA389WRP0
PCOVPA276WRE0
PCOVPA342WRF0
PCOVPA343WRF0
PCUSUA443WRP0
PDUC-A700WRF0
PPACGA097WRE0
PCUSUA474WRP0
Latch hook
Light mount plate
Waterproof cushion
Capacitor holder
Fan blade
Fan duct
Oven cavity (Not replaceable part)
Leg
Chassis support
Cushion
Waveguide cover
B-cover Right
B-cover Left
Cushion
Air separator
O-ring
Cushion
OVEN PARTS
∆
∆
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
DOOR PARTS
∆
∆
55555555-
1
2
3
4
5
6
7
8
FDORFA321WRT0
GWAKPA628WRF0
HPNL-A738WRRZ
LSTPPA175WRF0
MSPRTA084WRE0
PSHEPA622WRE0
GCOVHA390WRF0
XEPSD40P08000
Door panel
Door frame
Door screen
Latch head
Latch spring
Sealer film
Choke cover
Screw : 4mm x 8mm
6666-
1
2
3
4
FROLPA089WRK0
NTNT-A094WRE0
TINSEA896WRRZ
FW-VZB657WRE0
Turntable support
Turntable
Instruction book
Switch harness
MISCLANEOUS
30
R-204EWA
*
REF. NO.
6- 5
6- 6
6- 7
6- 8
6- 9
6-10
PART NO.
FW-VZB831WREZ
QW-QZA242WRZZ
TCAUAA265WRRZ
TCAUAA257WRRZ
TCAUAA266WRRZ
TCAUAA156WRR0
DESCRIPTION
Main wire harness
High voltage wire B
DHHS caution label
Monitor caution
Earth caution
User caution label
Q'TY
1
1
1
1
1
1
CODE
AQ
AF
AC
AC
AD
AF
2
2
1
1
5
1
2
12
4
2
3
1
AA
AB
AB
AA
AA
AA
AA
AA
AA
AC
AA
AA
SCREWS 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
XHPSD40P08K00
LX-EZA042WRE0
LX-WZA028WRE0
XHTSD40P12RV0
XHTSD40P08RV0
XHPSD30P06000
LX-CZ0052WRE0
XOTSD40P12000
XOTSE40P08000
LX-CZA070WRE0
XHPSD40P08000
XOTSD40P08000
Screw :
Special
Special
Screw :
Screw :
Screw :
Special
Screw :
Screw :
Special
Screw :
Screw :
4mm x 8mm
screw
washer
4mm x 12mm
4mm x 8mm
3mm x 6mm
screw
4mm x 12mm
4mm x 8mm
screw
4mm x 8mm
4mm x 8mm
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.
PACKING AND ACCESSORIES
TOP PAD ASSEMBLY
FPADBA387WRK0
DOOR PROTECTION SHEET
POLYETHYLENG BAG
SPADPA580WRE0
SSAKHA070WREZ
6-3 OPERATION MANUAL
6-2 TURNTABLE TRAY
MICROWAVE OVEN
BOTTOM PAD ASSEMBLY
FPADBA388WRK0
6-1
TURNRABLE SUPPORT
INTO THE
OVEN CAVITY
Not replaceable items.
TRAY PAD ASSY
(CPADBA244WRK0)
31
PACKING CASE
FPAK-A404WRKZ
R-204EWA
2
1
4
3
6
5
7-8
OVEN AND CABINET PARTS
7-10
A
A
7-8
2-1
7-9
7-12
7-10
1-9
B
B
7-8
4-3
7-11
4-2
C
1-8
4-17
C
7-9
6-8
6-7
6-9
7-4
4-5
4-14
1-2
1-3
4-14
D
7-5
D
7-5
4-6
4-7
7-5
A
4-11
A
1-7
E
1-5
6-2
7-3
7-1
7-6
1-11
E
1-6
4-9
4-4
4-16
7-7
1-10
F
6-1
1-1
4-10
7-2
1-2
7-1
F
4-1
7-8
1-1
4-15
4-3
4-8
1-4
G
G
2-2
7-8
2-3
4-13
7-8
7-8
7-8
2-3
H
7-8
H
4-12
7-8
1
2
4
3
32
5
6
R-204EWA
2
1
Befor attaching Control unit to
Control panel, foil side of Control
unit must be cleaned by ethylalcohol.
A
4
3
6
5
CONTROL PANEL PARTS
3-1
A
3-4
3-2
B
3-2-2
3-3
B
6-10
C
C
DOOR PARTS
5-6
5-8
3-2-1
D
D
5-7
E
E
5-1
5-8
5-2
5-3
F
F
5-4
5-5
MISCELLANEOUS
G
G
6-4
6-5
6-6
H
H
Actual wire harness may be different than illustration.
1
2
4
3
33
5
6
R-204EWA
COPYRIGHT © 2001 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.
2001 SHARP CORP. (6S1.700E) Printed in U.S.A
34
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