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 con-
R-25JT
tain circuitry capable of producing very high voltage and
current, contact with following parts may result in a severe,
possibly fatal, electrical shock. (High Voltage Capacitor, High
Voltage Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..)
TABLE OF CONTENTS
Page
PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICE TO
AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY...................INSIDE FRONT COVER
BEFORE SERVICING ......................................................................................................INSIDE FRONT COVER
WARNING TO SERVICE PERSONEL ..................................................................................................................1
GENERAL INFORMATION...................................................................................................................................4
TROUBLE SHOOTING GUIDE/ TEST PROCEDURE ........................................................................................11
TOUCH CONTROL PANEL .................................................................................................................................21
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ................................................................30
CONTROL PANEL CIRCUIT ...............................................................................................................................38
PARTS LIST ........................................................................................................................................................40
PACKING AND ACCESSORIES .........................................................................................................................43
SHARP CORPORATION
This document has been published to be used for after
sales service only.
The contents are subject to change without notice.
R-25JT
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 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.
WARNING TO SERVICE PERSONNEL
Microwave ovens contain circuitry capable of producing very high voltage and current, contact with
following parts
fatal, electrical shock.
(Example)
High Voltage Capacitor, High Voltage Power Trans-
former, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..
Read the Service Manual carefully and follow all
instructions.
may result in a severe, possibly
R-25JT
Don't Touch !
Danger High Voltage
Before Servicing
1. Disconnect the power supply cord ,and then
remove outer case.
2. Open the door and block it open.
3. Discharge two high voltage capacitors.
WARNING: RISK OF ELECTRIC SHOCK.
DISCHARGE THE TWO HIGH
VOLTAGE CAPACITORS BEFORE
SERVICING.
The high-voltage capacitors remain charged about 60
seconds after the oven has been switched off. Wait for 60
seconds and then short-circuit the connection of the highvoltage capacitors (that are the connecting lead of the
high-voltage rectifiers) against the chassis with the use of
an insulated screwdriver.
Whenever troubleshooting is performed the power supply
must be disconnected. It may, in some cases, be necessary
to connect the power supply after the outer case has been
removed, in this event,
1. Disconnect the power supply cord, and then remove
outer case.
2. Open the door and block it open.
3. Discharge two high voltage capacitors.
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 two high voltage capacitors.
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.
After repairing
1. Reconnect all leads removed from components during
testing.
2. Reinstall the outer case (cabinet).
3. Reconnect the power supply cord after the outer case is
installed.
4. Run the oven and check all functions.
Microwave ovens should not be run empty. To test for the
presence of microwave energy within a cavity, place a cup
of cold water on the oven turntable, close the door and set
the power to HIGH and set the microwave timer for two (2)
minutes. When the two minutes has elapsed (timer at zero)
carefully check that the water is now hot. If the water
remains cold carry out Before Servicing procedure and reexamine the connections to the component being tested.
When all service work is completed and the oven is fully
assembled, the microwave power output should be checked
and microwave leakage test should be carried out.
1
R-25JT
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
SERVICE MANUAL
COMMERCIAL
MICROWAVE OVEN
R-25JT
PRODUCT DESCRIPTION
R-25JT
FOREWORD
This Manual has been prepared to provide Sharp Electronics Corp.
Service Personnel with Operation and Service Information for the
SHARP MICROWAVE OVENS, R-25JT.
It is recommended that service personnel carefully study the entire
text of this manual so that they will be qualified to render satisfactory
customer service.
Check the interlock switches and the door seal carefully. Special
attention should be given to avoid electrical shock and microwave
radiation hazard.
WARNING
Never operate the oven until the following points are ensured.
(A) The door is tightly closed.
(B) The door brackets and hinges are not defective.
(C) The door packing is not damaged.
(D) The door is not deformed or warped.
(E) There is no other visible damage with the oven.
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.
GENERAL INFORMATION
OPERATION
TROUBLESHOOTING GUIDE AND
TEST PROCEDURE
TOUCH CONTROL PANEL
COMPONENT REPLACEMENT
AND ADJUSTMENT PROCEDURE
WIRING DIAGRAM
PARTS LIST
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
R-25JT
SPECIFICATION
ITEMDESCRIPTION
Power Requirements230/208 Volts 3.2 kW
Approx. 15.5 A at 208 V / Approx. 14.5 A at 230 V
60 Hertz / Single phase, 3 wire grounded
Power Output2100 watts (IEC 705 Test Procedure) Operating frequency of 2450MHz
Case DimensionsWidth 20-1/8"Height 13-1/4"Depth 18-1/2"
Cooking Cavity DimensionsWidth 13"Height 7-1/8"Depth 13"
Control ComplementTouch Control System
Digital Display
10 Number Pads
STOP/CLEAR pad
START pad
SELECTAPOWER pad (Power level: 0 to 100%)
SELECTATIME pad
DOUBLE QUANTITY pad
EXPRESS DEFROST pad
Memory SET pad
Memory CHECK pad
SIGNAL pad
WeightApprox. 68 lbs/ 31 kg
Safety StandardUL Listed FCC Authorized
DHHS Rules, CFR, Title 21, Chapter 1, Subchapter J
NSF Certified
GENERAL INFORMATION
GROUNDING INSTRUCTIONS
This appliance must be grounded. In the event of an electrical short circuit, grounding reduces the risk of electric shock by
providing an escape wire for the electric current. This appliance is equipped with a cord having a grounding wire with a
grounding plug. The plug must be plugged into an outlet that is properly installed and grounded.
WARNING: Improper use of the grounding plug can result in a risk of electric shock. The electrical requirements are 230/
208 Volt, 60 Hz, AC only, and 20 Amp or more 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. If it is necessary to use an extension cord,
use only a 3-wire extension cord that has a 3-blade grounding plug and a 3-slot
receptacle that will accept the plug on the appliance. The marked rating of the
extension cord should be AC 230/208 Volt 20 Amp.
VOLTAGE SELECT
The oven has been preset for 230V operation.
If you need to change this oven for 208V operation, follow instructions below.
1. Unplug oven.
2. Remove one screw(A) from the Voltage Select Cover located on back of the
oven near the bottom.
3. Remove the Voltage Select Cover and rotate 180 degrees.
4. Reinstall the Voltage Select Cover using one screw(A) removed in Step 2.
5. Plug power cord into wall outlet.
Your oven is now ready for 208V, 60Hz operation.
Note:If “EE4” or “EE5” appears in the lighted digital display, a voltage adjustment
must be made.
Power supply
cord
Receptacle Box Cover
3-Pronged plug
(6-20P)
3-Pronged, Receptacle
(6-20R)
208 V
230 V
230 V208 V
(A)
4
OVEN DIAGRAM
R-25JT
10
12
11
1. Touch control panel
2. Door latch openings
3. Ceramic shelf
4. Splash cover
5. Oven light
6. Air intake filter
7. Air intake openings
8. Door seals and sealing surfaces
9. Door hinges
10.Oven door with see-through window
11.Door latches
12.Door handle
13.Service window for replacing the oven
light bulb.
14.Ventilation openings
15.Power supply cord
16.Mounting plate
17.Screw for mouning plate
18.Voltage select cover
Control Panel
19.DOUBLE QUANTITY pad
20.EXPRESS DEFROST pad
21.Ten number pads for time and memory
programming
22.SELECTATIME pad
23.STOP/CLEAR pad; touch to stop
operation of oven and clear remaining
heating time
24.SELECTAPOWER pad for setting
variable power level
25.START pad; touch to operate oven after
door is closed and time is set
26.SET pad for setting memory
27.CHECK pad for checking memory
28.SIGNAL pad for setting signal sound
5
9
3
4
2
16
17
1
13
15
14
18
678
DEFONNO.X2CHECK
19
22
24
26
DOUBLE
QUANTITY
SELECTA TIME STOP/CLEAR
SELECTAPOWER
SETCHECKSIGNAL
EXPRESS
DEFROST
11
1
12
2
13
3
14
4
15
5
16
6
17
7
18
8
19
9
20
0
START
20
21
23
25
28
27
5
R-25JT
OPERATION
DESCRIPTION OF OPERATING SEQUENCE
The following is a description of component functions during
oven operation.
OFF CONDITION
Closing the door activates the door sensing switch and
secondary interlock switches (1), (2). (In this condition, the
monitor switches (1) & (2) contacts are opened.) When the
oven is plugged in, and the rated voltage is supplied to the
control unit, (figure O-1), the display will show " . ".
IDLE CONDITION
When the door is opened, the contacts of the door sensing
switch open, initiating the following:
1. A signal is input to the control unit energizing the coil of
shut-off relay (RY-1).
2. The shut-off relay (RY-1) contacts close completing
circuits to turn on the oven lamp, blower motor and stirrer
motors.
3. If the door remains open, 60 seconds later the control
unit de-energizes shut-off relay (RY-1) turning off the
oven lamp, blower motor and stirrer motors.
When the door is closed, the door sensing switch contacts
close. With the closing of the door sensing switch contacts,
an additional circuit is provided which will permit the operation of the oven when one of the touch pads is depressed.
Since the control is enabled through the door sensing
switch, the door must be closed before the touch pads will
be effective. When the door is closed, a full 60 second IDLE
condition is always provided for selecting and pressing the
desired touch pads. A 60 second IDLE condition will also
follow the end of each cook cycle.
COOKING CONDITION
When the door is closed from the open position and Memory
pad is touched the, following will occur:
1. The contacts of relays are closed and components
connected to the relays are turned on (For details, refer
to Figure O-3)
2. Rated voltage is supplied to the primary winding of the
power transformer and is converted to about 3.15 volts
output on the filament winding, and approximately 2305
volts 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 oven will revert
to the IDLE condition.
6. When the door is opened during a cook cycle, monitor
switches (1) & (2), door sensing switch, secondary
interlock switches (1), (2) and primary interlock relays
(1), (2) are activated with the following results. The
circuits to the high voltage components are de-energized,
and the digital read-out displays " . " and cooking is
cancelled (in the case of Memory cooking).
7. The monitor switch (1) is electrically monitoring the
operation of the secondary interlock switch (1) and
primary interlock relay (1), and monitor switch (2) is
electrically monitoring the operation of the secondary
interlock switch (2) and primary interlock relay (2), and
monitor switches (1), (2) are mechanically associated
with the door so that it will function in the following
sequence.
(1)When the door opens from a closed position, the contacts
of the primary interlock relays (1), (2) and secondary
interlock switches (1), (2) open. Then the monitor switch
contacts close.
(2) When the door is closed from the open position, the
monitor switches (1), (2) contacts first open, and then the
contacts of the secondary interlock switches (1), (2)
close.
If the secondary interlock switches (1), (2) and primary interlock
relays (1), (2) fail with their contacts closed when the door is
opened, the closing of the monitor switches (1), (2) contacts will
form a short circuit through the monitor fuse, secondary interlock switches (1), (2) and primary interlock relays (1), (2),
causing the monitor fuse to blow.
VARIABLE POWER COOKING
When Variable Cooking Power is programmed, the rated
voltage A.C. is supplied to the power transformer intermittently
through the contacts of relay (RY-2, RY-3). Relays RY-2 and
RY-3 are operated by the control unit within an interval second
time base. Microwave power operation is as follows:
POWER LEVELON TIMEOFF TIME
100%32 sec.0 sec.
90%30 sec.2 sec.
80 %26 sec.6 sec.
70%24 sec.8 sec.
60%22 sec.10 sec.
50%18 sec.14 sec.
40%16 sec.16 sec.
30%12 sec.20 sec.
20% 8 sec.24 sec.
10% 6 sec.26 sec.
0% 0 sec.32 sec.
Note:The ON/OFF time ratio does not exactly correspond
with the percentage of microwave power, because
approx. 2 seconds are needed for heating of the
magnetron filament.
6
R-25JT
TWO MAGNETRON OPERATION SYSTEM
Two magnetrons (1), (2) are equipped in order to get higher
microwave power output. The primary windings of the
power transformers (1), (2) are connected so that each
magnetron can be oscillated alternatively according to the
frequency of the power supply. Refer to the Figure B-1.
COMMERCIAL
FREQUENCY
(60HZ)
POWER OUTPUT
BY MAGNETRON 1
POWER OUTPUT
BY MAGNETRON 2
Figure B-1. Operation of Magnetron
OPERATION OF
MAGNETRON
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED OR 1 MINUTE AFTER COOK OFF
2. " . " APPEARS ON DISPLAY
PRIMARY
INTERLOCK
RELAY (1)
PRIMARY
INTERLOCK
RELAY (2)
TAB1
DOOR SENSING
SWITCH
OL
OVEN LAMP
STIRRER MOTOR
OL
TAB2
BLKWHT
208/230V 60Hz
FUSE 20A
GRN
OVEN
TEMP.
FUSE
BLOWER
MOTOR
TEMP.
FUSE
A7
RY1
A1A3B2B1
A5
V.S.
NC
SW (1)
COM
SM
BM
SM
BLOWER MOTOR
RY2
RY3
SECONDARY INTERLOCK
SWITCHE(1)
SECONDARY INTERLOCK
SWITCHE(2)
H1
H3
B3
RED
BLK
OVEN
THERMISTOR (2)
BLK
MAGNETRON THERMISTOR
OVEN
THERMISTOR (1)
GRY
WHT
GRY
MAGNETRON
TEMP. FUSE (1)
MAGNETRON
TEMP. FUSE (2)
RED
BLK
MONITOR SWITCH (2)
MONITOR SWITCH (1)
V.S.SW (3)
WHT
NC
COM
VOLTAGE SELECT
SWITCH (V.S.SW) (2)
COM
NC
POWER
TRANSFORMER (1)
CAPACITOR (1)
0.94µF
POWER
TRANSFORMER (2)
CAPACITOR (2)
0.94µF
H.V. RECTIFIER (1)
H.V. RECTIFIER (2)
MAGNETRON (1)
MAGNETRON (2)
Figure O-1. Oven Schematic-OFF Condition (208 V Condition)
7
R-25JT
SCHEMATIC
NOTE: CONDITION OF OVEN
1. FOR 1MINUTE AFTER DOOR OPENED.
2. " . " APPEARS ON DISPLAY.
PRIMARY
INTERLOCK
RELAY (1)
PRIMARY
INTERLOCK
RELAY (2)
TAB1
DOOR SENSING
SWITCH
OL
OVEN LAMP
STIRRER MOTOR
OL
TAB2
BLKWHT
208/230V 60Hz
FUSE 20A
GRN
OVEN
TEMP.
FUSE
BLOWER
MOTOR
TEMP.
FUSE
A7
RY1
A1A3B2B1
A5
V.S.
NC
SW (1)
COM
SM
BM
SM
BLOWER MOTOR
RY2
RY3
SECONDARY INTERLOCK
SWITCHE(1)
SECONDARY INTERLOCK
SWITCHE(2)
H1
H3
B3
RED
BLK
OVEN
THERMISTOR (2)
BLK
MAGNETRON THERMISTOR
OVEN
THERMISTOR (1)
GRY
WHT
GRY
MAGNETRON
TEMP. FUSE (1)
MAGNETRON
TEMP. FUSE (2)
RED
BLK
MONITOR SWITCH (2)
MONITOR SWITCH (1)
V.S.SW (3)
WHT
NC
COM
VOLTAGE SELECT
SWITCH (V.S.SW) (2)
COM
NC
POWER
TRANSFORMER (1)
CAPACITOR (1)
0.94µF
POWER
TRANSFORMER (2)
CAPACITOR (2)
0.94µF
H.V. RECTIFIER (1)
H.V. RECTIFIER (2)
MAGNETRON (1)
MAGNETRON (2)
Figure O-2. Oven Schematic-IDLE Condition (208 V Condition)
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. SELECTATIME PAD TOUCHED.
3. COOKING TIME PROGRAMMED.
4. START PAD TOUCHED.
FUSE 20A
OVEN
TEMP.
FUSE
BLOWER
MOTOR
TEMP.
BLKWHT
208/230V 60Hz
GRN
FUSE
A7
TAB1
RY1
A1A3B2B1
A5
V.S.
NC
SW (1)
COM
OL
SM
BM
STIRRER MOTOR
SM
BLOWER MOTOR
OL
PRIMARY
INTERLOCK
RELAY (1)
PRIMARY
INTERLOCK
RELAY (2)
TAB2
DOOR SENSING
SWITCH
OVEN LAMP
RY2
RY3
SECONDARY INTERLOCK
SWITCHE(1)
SECONDARY INTERLOCK
SWITCHE(2)
H1
H3
B3
RED
BLK
OVEN
THERMISTOR (2)
BLK
MAGNETRON THERMISTOR
OVEN
THERMISTOR (1)
GRY
WHT
GRY
MAGNETRON
TEMP. FUSE (1)
MAGNETRON
TEMP. FUSE (2)
RED
BLK
MONITOR SWITCH (2)
MONITOR SWITCH (1)
V.S.SW (3)
WHT
NC
COM
VOLTAGE SELECT
SWITCH (V.S.SW) (2)
COM
NC
POWER
TRANSFORMER (1)
CAPACITOR (1)
0.94µF
POWER
TRANSFORMER (2)
CAPACITOR (2)
0.94µF
H.V. RECTIFIER (1)
H.V. RECTIFIER (2)
MAGNETRON (1)
MAGNETRON (2)
Figure O-3. Schematic-Cooking Condition (208 V Condition)
8
DESCRIPTION AND FUNCTION OF COMPONENTS
R-25JT
DOOR OPEN MECHANISM
1. The door release lever is pulled.
2. The upper latch head is lifted up by the linked door
release lever.
3. The latch lever is lifted up by the door release lever.
4. The joint lever is lifted up by the latch lever.
5. The lower latch head is lifted up by the joint lever.
6. Now both latch heads are lifted up, so they can be
released from the latch hook.
7. Now the door can be opened.
Door release
lever
Joint lever
Latch lever
Latch head
Latch head
Switch lever A
Monitor switch (2)
Monitor switch (1)
Latch hook
Switch lever B
Secondary interlock
switch (2)
Secondary interlock
switch (1)
Door sensing switch
Switch lever C
Figure D-1. Door Open Mechanism
DOOR SENSING SWITCH
The door sensing switch is activated by the latch head of the
door and switch lever C. When the door is opened, the
contacts of the switch open and interrupt the circuit to the
coils of the primary interlock relays (1), (2). The contacts of
the primary relays (1), (2) then open and interrupt the circuit
to the primary winding of the power transformers. At this
time, the contacts of relay RY1 close and the blower motor,
stirrer motors and oven lamps are energized for 1 minute.
SECONDARY INTERLOCK SWITCHES (1), (2)
The secondary interlock switches (1), (2) are activated by
the upper latch head of the door and switch lever B. When
the door is opened, the contacts of the switch open and
interrupt the circuit to the primary winding of the power
transformers (1), (2).
MONITOR SWITCHES (1), (2)
The monitor switches (1), (2) are mounted in the upper
position of the latch hook. The monitor switches are activated by the upper latch head of the door and switch lever
A. When the door is opened, the contacts of the monitor
switches close. Monitor switch (1) is intended to render the
oven inoperative by means of blowing the monitor fuse,
when the contacts of the primary interlock relay (1) and
secondary interlock switch (1) fail to open when the door is
opened. Monitor switch (2) is intended to render the oven
inoperative by means of blowing the monitor fuse, when the
contacts of the primary interlock relay (2) and secondary
interlock switch (2) fail to open when the door is opened.
Functions:
With the door shut, the contacts of the door sensing switch
and the secondary interlock switches (1), (2) are closed and
the contacts of the monitor switches (1), (2) are open.
1. When the door is opened, the contact of the door sensing
switch and secondary interlock switches (1), (2) are
opened first, then the contact of the monitor switches (1),
(2) are closed.
2. As the door goes to a closed position, the contacts of the
monitor switches (1), (2) are opened first, then the
contacts of the door sensing switch and the secondary
interlock switches (1), (2) close.
3. If the door is opened, and the contacts of the primary
interlock relay and secondary interlock switch of the
same circuit fail to open, the monitor fuse blows
simultaneously with closing of the monitor switch contacts
of that circuit (1 or 2).
CAUTION: BEFORE REPLACING A BLOWN MONITOR
FUSE TEST THE DOOR SENSING SWITCH,
PRIMARY INTERLOCK RELAYS (1), (2), SECONDARY INTERLOCK SWITCHES (1), (2) AND
MONITOR SWITCHES (1), (2) FOR PROPER
OPERATION. (REFER TO CHAPTER "TEST
PROCEDURE").
NOTE: MONITOR FUSE AND SWITCH ARE REPLACED
AS AN ASSEMBLY.
MAGNETRON TEMPERATURE FUSES (1), (2)
The temperature fuses (1), (2) located on the top of the
upper and lower waveguide, are designed to prevent damage to the magnetrons (1), (2). If an over heated condition
develops in the tube due to blower motor failure, obstructed
air ducts, dirty or blocked air intake, etc., the circuit to the
magnetrons are interrupted. Under normal operation, the
temperature fuses remains closed. However, when abnormally high temperatures are generated within the magnetron,
the temperature fuse will open at 302˚F (150˚C) causing the
microwave energy to stop. The defective temperature fuse
must be replaced with new rated one.
OVEN TEMPERATURE FUSE
The temperature fuse, located on the side of the exhaust
duct assembly, 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 control unit, the temperature fuse will
open. Under normal operation, the oven temperature fuse
remains closed. However, when abnormally high temperatures are generated within the oven cavity, the oven temperature fuse will open at 248˚F (120˚C), causing the oven
to shut down. The defective temperature fuse must be
replaced with new rated one.
9
R-25JT
BLOWER MOTOR TEMPERATURE FUSE
This temperature fuse protects the blower motor against
overheating. If its temperature goes above 248˚F (120˚C)
because the blower motor is stalled or the ventilation openings are blocked, the contacts of the temperature fuse will
open. The line voltage to the control unit will be cut off and
the operation of the oven will be stopped. The defective
temperature fuse must be replaced with a new one.
OVEN THERMISTOR (1)
The thermistor is a negative temperature coefficient type.
The temperature in the exhaust duct is detected through the
resistance of the thermistor.
If the temperature is high, the control panel will display “EE7”
and the oven will stop to avoid overheating and catching fire.
If the thermistor is open, the control panel will display "EE6"
and the oven will stop.
OVEN THERMISTOR (2)
This thermistor detects temperature of the oven cavity
bottom plate. The thermistor is a negative temperature
coefficient type. The temperature is detected through the
resistance of the thermistor.
If the temperature is high, the control will display “EE17” and
the oven will stop.
MAGNETRON THERMISTOR
The thermistor is a negative temperature coefficient type.
The air temperature around the upper magnetron is detected through the resistance of the thermistor.
If the temperature is high, the control panel will display
"EE17" and the oven will stop to protect the lower magnetron
against overheat.
If the oven thermistor (2) and the magnetron thermistor are
open at the same time, the control panel will display "EE16"
and the oven will stop.
SELECT SWITCHES (1) - (3)
The select switch assembly is an array of three separate
switches which may be configured for either 208V or 230V
operation (see General Information section, voltage select).
These switches are connected to the windings of components specified in the table below and make those components compatible with the specified line voltage by changing
their internal windings. For 208V operation contacts (Normal Open) of the all switches are open.
Oven in the 208V setting: contacts between common and
normally open are closed.
Oven in the 230V setting: contacts between common and
normally closed are closed.
BLOWER MOTOR
The blower motor drives a blade which draws external cool
air into the oven. This cool air is directed through the air
vanes surrounding the magnetrons and cools the
magnetrons. This air is channelled through the oven cavity
to remove steam and vapours given off from the heating
foods. It is then exhausted through the exhausting air vents
at the oven cavity.
STIRRER MOTOR
The upper and lower stirrer motors drive stirrer antennas to
stir the microwave radiation from the upper and lower
waveguides.
OVEN LAMPS
The oven cavity light illuminates the interior of the oven so
that food being cooked can be examined visually through
the door window without having to open the door. The oven
lamp is on during the cooking cycle and idle condition.
10
R-25JT
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 switches (1), (2),
primary interlock relays RY2, RY3, door sensing switch and secondary interlock switches (1), (2), before
replacing the monitor fuse. If monitor fuse is replaced, the monitor switch (1) and/or (2) 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 two high voltage capacitors.
4. Disconnect the leads to the primaries of the two power transformers.
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 two high voltage capacitors.
4. Reconnect the all leads removed from components during testing.
5. Reinstall the outer case (cabinet).
6. Reconnect the power supply cord after the outer case is installed.
7. Run the oven and check all functions.
11
R-25JT
HIGH POWER SUPPLY VOLTAGE
CKCK
RST RSTRST
NO LOAD OPERATION
EXCEED MAX. HEATING TIME
LOW POWER SUPPLY VOLTAGE
NO POWER AT OUTLET
SHORT IN POWER SUPPLY CORD
LOOSE WIRING
AIR FLOW BLOCKED
SITTER MOTORS
OPEN FOIL PATERN ON P.W.B.
RELAY (RY-3)
RELAY (RY-2)
RELAY (RY-1)
KEY UNIT
TOUCH CONTROL PANEL
PRIMARY INTERLOCK SYSTEM (1), (2)
SECONDARY INTERLOCK SWITCH (1), (2)
HIGH VOLTAGE CAPACITOR (1), (2)
H.V. RECTIFIER (1), (2)
POWER TRANSFORMER (1), (2)
ABCDEF FGI JJ JJHHHKKKLMNNNOCKCKCKCKCK
MAGNETRON (1), (2)
(1)
(1)
(1)
(1)
(1)
(1)
(2)
(2)
(2)
(2)
(2)
(2)
TEST PROCEDURE
DEFECTIVE PARTS
POSSIBLE CAUSE AND
PROBLEM
Home fuse blows when power cord is plugged into wall
receptacle
Monitor fuse blows when power cord is plugged into wall
receptacle.
" . " does not appear in display when power cord is first
plugged into wall receptacle.
Blower motor does not operate. (Oven lamp(s) and stirrer
motors go on for 1 minute after door is opened.)
Blower motor, oven lamp(s) and stirrer motors do not go on for
1 minute after door is opened.
Blower motor and stirrer motors go on but oven lamp(s) do not
light for 1 minute after door is opened.
Blower motor, oven lamp(s) and stirrer motors keep going on
after more than 1 minute when door is opened and closed.
Blower motor, oven lamp(s) and stirrer motors do not go on in
cook cycle.
Oven goes into a cook cycle but shuts down before and off
cooking cycle.
Oven does not go into cook cycle when START pad is touched.
Low or no power is produced during cooking condition. (The
OFF
CONDITION
CONDITION
COOKING
CONDITION
12
food is heated incompletely or not heated at all.)
Extremely uneven heating is produced in oven load (food).
Variable cooking does not operates properly, except HIGH
power functions.
"EE1" Magnetron (1) failure.
"EE2" Magnetron (2) failure.
"EE3" Magnetron (1) and (2) failure.
"EE4" Voltage is too high.
"EE5" Voltage is too low.
"EE6" Oven thermistor (1) failure.
"EE7" Exhaust air temperature is too high.
"EE8" Relay melt short.
"EE9" Maximum time is exceeded.
"EE16" Oven thermistor (2) and Magnetron thermistor are
open.
"EE17" Magnetron temperature is too high.
ERROR
MODE
TEST PROCEDURES
R-25JT
PROCEDURE
LETTER
AMAGNETRON ASSEMBLY TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge two high voltage capacitors.
4. To test for an open filament, isolate the magnetron from the high voltage circuit. A continuity check
across the magnetron filament leads should indicate less than 1 ohm.
5. To test for a shorted magnetron, connect the ohmmeter leads between the magnetron filament leads
and chassis ground. This test should indicate an infinite resistance. If there is little or no resistance
the magnetron is grounded and must be replaced.
6. Reconnect all leads removed from components during testing.
7. Reinstall the outer case (cabinet).
8. Reconnect the power supply cord after the outer case is installed.
9. Run the oven and check all functions.
MICROWAVE OUTPUT POWER
The following test procedure should be carried out with the microwave oven in a fully assembled
condition (outer case fitted).
HIGH VOLTAGES ARE PRESENT DURING THE COOK CYCLE, SO EXTREME CAUTION SHOULD
BE OBSERVED.
Power output of the magnetron can be measured by performing a water temperature rise test. This test
should only be used if above tests do not indicate a faulty magnetron and there is no defect in the following
components or wiring: 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:
COMPONENT TEST
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 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 55.4
to 103˚F(30.8 to 57.2˚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 208/230 volts and the oven cavity is clean.
BPOWER TRANSFORMER TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge two high voltage capacitors.
4. 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 57.1 ohms; the resistance of the filament coil should be less than 1 ohm.
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.
13
R-25JT
TEST PROCEDURES
PROCEDURE
LETTER
8. 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.)
CHIGH VOLTAGE RECTIFIER (1) AND/ OR (2) TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge two high voltage capacitors.
4. 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.
DHIGH VOLTAGE CAPACITOR (1) AND/ OR (2) TEST
COMPONENT TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge two high voltage capacitors.
4. 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.
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.
ESECONDARY INTERLOCK SWITCH (1) AND/ OR (2) TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge two high voltage capacitors.
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 secondary interlock switch.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
FPRIMARY 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 two high voltage capacitors.
4. Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal
14
TEST PROCEDURES
SCREW DRIVER
MONITOR SWITCH (2)
OHMMETER
MONITOR SWITCH (1)
LATCH HOOK
R-25JT
PROCEDURE
LETTER
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.
NOTE: If the door sensing switch contacts fail in the open position and the door is closed, the blower
motor, stirrer motors and oven light will be activated by RY1.
PRIMARY INTERLOCK RELAY (RY2, RY3)
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge two high voltage capacitors.
4. Disconnect two (2) wire leads from the male tab terminals of the Primary Interlock Relay RY2 and/
or RY3. 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.
GMONITOR SWITCH (1) AND/ OR (2) TEST
COMPONENT TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge two high voltage capacitors.
4. Before performing this test, make sure that the secondary interlock switches (1), (2) and the primary
interlock relays RY2, RY3 are operating properly, according to the above Switch Test Procedure.
Disconnect the wire lead from the monitor switches (1), (2) (COM) terminals. Check the monitor
switches (1), (2) 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
upper 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 switches, reconnect the wire lead
to the monitor switch (COM) terminals
and check the continuity of the monitor
circuit.
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.
HVOLTAGE SELECT SWITCHES TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge two high voltage capacitors.
4. Isolate switch and check the contacts by using an ohmmeter with following table. If improper operation
is indicated, make the necessary switch adjustment or replacement.
Plunger operationBetween COM. and NO.Between COM. and NC.COM.: Common terminal
Plunger releasedOpen circuitClose circuitNO.:Normal Open terminal
Plunger operationClose circuitOpen circuitNC.:Normal Close terminal
Table: Switch Connection
15
R-25JT
TEST PROCEDURES
PROCEDURE
LETTER
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.
IBLOWN MONITOR FUSE TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge two high voltage capacitors.
4. If the monitor fuse is blown when the door is opened, check the primary interlock relays RY2, RY3,
secondary interlock switches (1), (2) and monitor switches (1), (2) 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
RELAYS, SECONDARY INTERLOCK SWITCHES, DOOR SENSING SWITCH AND MONI-
TOR SWITCHES 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.
COMPONENT TEST
Rear
cabinet
side
N.C.
Select switch (1)
Oven
cavity
COM.
Select
switch (2)
N.O
Select switch (3)
Select switch angle
Screw
Switch
spacer
JTEMPERATURE FUSE TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge two high voltage capacitors.
4. A continuity check across the temperature fuse terminals should indicate a closed circuit unless the
temperature of the temperature fuse reaches specfied temperature as shown below.
OpenCloseDisplay or
temperaturetemperatureConditionCheck point
Magnetron temperature fuse (1)
150˚C
Magnetron temperature fuse (2)
Blower motor temperature fuse
Oven temperature
fuse
120˚C
120˚C
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 TEMPERATURE FUSE INDICATES AN OPEN CIRCUIT AT ROOM TEMPERA-
TURE, REPLACE TEMPERATURE FUSE.
Non resetable
type
Non resetable
type
Non resetable
type
EE1
EE3
EE2
Oven shut
off
Oven shut
off
Magnetron (1) Failure:
Test magnetron (1) and Blower fan motor.
Magnetron (1), (2) Failure: Test magnetron (1), (2).
Check blower fan motor and ventilation opening.
Magnetron (2) Failure:
Test magnetron (2) and Blower fan motor.
Check blower fan motor and ventilation opening or
rocked rotating of blower fan motor.
Food has been burned in oven.
Temperature of oven inside is very high.
16
TEST PROCEDURES
R-25JT
PROCEDURE
LETTER
KTHERMISTOR TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge two high voltage capacitors.
4. Follow the procedures below for each thermistor.
4-1. MAGNETRON THERMISTOR TEST
Disconnect connector-H from the CPU unit. And disconnect the connector of the magnetron thermistor
from the switch harness. Measure the resistance of the thermistor with an ohmmeter. Connect the
ohmmeter leads to the leads of the thermistor.
If the meter does not indicate above resistance, replace the thermistor.
4-2. OVEN THERMISTOR (1) TEST
Disconnect connector-B from the CPU unit. Measure the resistance of the thermistor with an ohmmeter.
Connect the ohmmeter leads to the leads of the thermistor.
If the meter does not indicate above resistance, replace the thermistor.
Disconnect connector-H from the CPU unit. And disconnect the connector of the magnetron thermistor
from the switch harness. Measure the resistance of the thermistor with an ohmmeter. Connect the
ohmmeter leads to the leads of the thermistor.
If the meter does not indicate above resistance, replace the thermistor.
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.
LTOUCH 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 two high voltage capacitors.
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.
17
R-25JT
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
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.
2) Open the door and block it open.
3) Discharge two high voltage capacitors.
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 M) to determine if control unit is faulty.
Re-connect the power supply cord. And check for followings.
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 display
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) 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 two high voltage capacitors.
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.
MKEY UNIT TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge two high voltage capacitors.
4. 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 connecter). 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
18
TEST PROCEDURES
R-25JT
PROCEDURE
LETTER
NRELAY TEST
COMPONENT TEST
control unit does not respond, it is faulty and must be replaced. If a specific pad does not respond,
the above method may be used (after clearing the control unit) to determine if the control unit or key
pad is at fault.
5. Reconnect all leads removed from components during testing.
6. Re-install the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
G 9
G 10
G 11
G 12
G 1
G 2
G 3
5
6
DOUBLE
QUANTITY
EXPRESS
DEFROST
3
4
17
18
SELECTA
7
POWER
SELECTA
8
TIME
9
0
G 7G 6G 5G 4
STARTSET
STOP /
CLEAR
11131519
1
12141620
2
G 8
CHECK
SIGNAL
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge two high voltage capacitors.
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 Pins No. 5 (or No. 3 at 230V) and No. 7 of the 7
pin connector (A) on the control unit with an A.C. voltmeter.
The meter should indicate rated voltage, if not check oven circuit.
RY1, RY2 and RY3 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
8. Disconnect the power supply cord, and then remove outer case.
9. Open the door and block it open.
10. Discharge two high voltage capacitors.
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 function.
OFOIL 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.
19
R-25JT
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
1) Disconnect the power supply cord, and then remove outer case.
2) Open the door and block it open.
3) Discharge two high voltage capacitors.
4) Follow the troubleshooting guide given below for repair.
STEPSOCCURRENCECAUSE OR CORRECTION
1Only pattern at "a" is broken.*Insert jumper wire J1 and solder.
2Pattern at "a" and "b" are broken.*Insert the coil RCILF2003YAZZ between "c" and "d".
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 865Ω± 10% between
TB1
7
a
(VRS2)
CT1
(J1)
17
c
b
POWER
T1
d
VRS1
208V terminals and 970Ω± 10%
between 230V terminals). If any
abnormal condition is detected, replace
POWER
12
the defective parts.
P
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 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 two high voltage capacitors.
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.
STEPSOCCURRENCECAUSE OR CORRECTION
1The rated AC voltage is not present to power Check supply voltage and oven power cord.
terminal of CPU connector CN-A.
2The rated AC voltage is present at primaryLow voltage transformer or secondary circuit defective.
side of low voltage transformer.Check and repair.
8) Disconnect the power supply cord, and then remove outer case.
9) Open the door and block it open.
10) Discharge two high voltage capacitors.
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.
20
TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOUCH CONTROL PANEL
R-25JT
The touch control section consists of the following units as
shown in the touch control panel circuit.
(1) Control Unit
(2) Key Unit
The principal functions of these units and the signals communicated among them are explained below.
1. Control Unit
Signal of key touch and oven function control are all
processed by one microcomputer.
1) Power Supply Circuit
This circuit changes output voltage at the secondary side
of the low voltage (T1) transformer to voltages required at
each part by full wave rectifying circuit, constant voltage
circuit, etc..
2) ACL Circuit
This is an Auto-clear Circuit, i.e., a reset circuit, which
enables IC1 to be activated from initial state.
3) Power Synchronizing Signal Generating Circuit
This is a circuit for generating power synchronizing signal
by virtue of the secondary side output of transformer T1.
This signal is used as a basic frequency for time processing.
4) Clock Circuit
This is a circuit for controlling clock frequency required for
operating IC1.
5) IC1 (Main Processor)
This is a one-chip microcomputer, responsible for controlling the entire control unit.
6) IC2 (Memory Processor)
This is a memory IC, responsible for memory function.
7) IC3
This is a IC for driving light emitting diode.
8) Display Circuit
This is a circuit for driving light emitting diode by IC1 output.
9) Key Input Circuit
This is a circuit for transmitting key input information to IC1.
10) Sound-body Driving Circuit
This is a circuit for driving sound body by IC1 output.
11) Relay Driving Circuit
This is a circuit for driving output relay by IC1 output.
12) Door Sensing Switch Circuit
This is a circuit for driving IC1 to detect door opening/
closing.
13) Exhaust Air Temperature Detecting Circuit
This is a circuit for transmitting output change of thermistor
(Oven thermistor (1)) to IC1.
14) Magnetron Temperature Circuit
(Detect no load or fan lock)
This is a circuit for transmitting output change of thermistor
(Magnetron thermistor) to IC1.
15) Oven Cavity Temperature Detecting Circuit
This is a circuit for transmitting output change of thermistor
(Oven thermistor (2)) to IC1.
21
R-25JT
16) High Voltage Monitoring Circuit.
This circuit detects problems in the magnetron / high
voltage circuit by sensing a variation in the current flowing
through the primary winding of the high voltage transformer.
During heating, the primary current of the high voltage
transformers also flows through the primary winding of the
current transformer CT1. This causes a current to be
induced in the secondary winding of CT1 and results in an
AC voltage which is determined by R100.
This AC voltage is then half wave rectified by D100 and
smoothed (filtered) by C100.
This AC voltage is the input to the AN3 port of IC1, which
determines if there is a magnetron / high voltage problem.
TB1
TB2
CT1
D100R102
C100
820F
R100
47µ/10v
R101
4.7k
100k
C101
To AN3 of IC1
0.01µ/16v
Figure T-1. High Voltage Monitoring Circuit
17) Supply Voltage Detecting Circuit
This is a circuit for detecting troubles of input voltage at
microwave oven. The function of this circuit is to divide the
variation of voltage across C1 to supply voltage variation
by ZD1, R1 and R2 and to put the result to AN6 port of IC1
for detection.
The key unit is composed of a matrix circuit in which when
a key it touched, one of signals P30--P34 generated by the
LSI, is passed through the key and returned to the LSI as
one of signals P24--P27.
This model has 20 Memory pads.
When the oven is shipped, Memory pad 1 to 10 are set as
follows: fig.1.
Memory No.Cook TimeOutput Power
110 sec.100%
220 sec.100%
330 sec.100%
445 sec.100%
51 min.100%
61 min. 15 sec.100%
71 min. 30 sec.100%
82 min.100%
92 min. 30 sec.100%
03 min.100%
(fig. 1)
This model has a double quantity pad. When the oven is
shipped, Magnification "1.8" is preset in the double quantity pad.
This model has an express defrost pad. When the oven is
shipped, express defrost is set as follows: fig.2.
1 STAGE2 STAGE3 STAGE
FORMULA P = 0.2T + 20P = 0.13T + 30P = 0.67T - 50
POWER40 %30 %20 %
T : Total cooling time
(fig. 2)
FIgure T-2. Supply Voltage Detecting Circuit
When 1/2 total cooking time is passed, the signal will
sound and "CHECK" indicator will flash.
22
DESCRIPTION OF LSI
H
L
16.7 msec
During cooking
LSI(IZA633DR)
The I/O signal of the LSI(IZA633DR) is detailed in the following table.
Pin No.SignalI/ODescription
1VCCINPower source voltage: +5V.
VC voltage of power source circuit input.
2/3
VEE/AVSSINConnected to GND
4VREFINConnected to VC. (+5V)
5AN7IN
Temperature measurement input: INTAKE THERMISTOR.
By inputting DC voltage corresponding to the temperature detected by the thermistor, this
input is converted into temperature by the A/D converter built into the LSI.
6AN6INUsed (judge for input voltage).
7-8AN5-AN4IN
Terminal to change functions according to the model.
Signal in accordance with the model in operation is applied to set up its function.
9AN3INA/D input for troubleshooting Magnetron 1. and/or Magnetron 2.
10AN2IN
Temperature measurement input: OVEN THERMISTOR.
By inputting DC voltage corresponding to the temperature detected by the thermistor, this
input is converted into temperature by the A/D converter built into the LSI.
11AN1IN
Input signal which communicates the door open/close information to LSI.
Door closed; "L" level signal (0V).
Door opened; "H" level signal (+5V).
12AN0INTemperature measurement input: FAN LOCK THERMISTOR.
By inputting DC voltage corresponding to the temperature detected by the thermistor, this
input is converted into temperature by the A/D converter built into the LSI.
13-14P55-P54OUT
Magnetron high-voltage circuit driving signal.
To turn on and off the cook relay. In 100% power level operation, "H" level during cooking;
"L" level otherwise. In other power level operation (90,80,70,60,50,40,30,20,10 or 0%), "H"
and "L" level is repeated according to power level.
15P53OUTOven thermistor circuit power supply control signal.
Output the "H" signal to supply power to oven thermistor circuit about 1.7msec. after plugging
in.
16-18P52-P50INTerminal not used.
19P47OUT
Signal to sound buzzer.
This signal is to control the 2.5kHz continuous
signal through IC3.
A: key touch sound.
B: Guydance sound.
A
1 sec
B
C: Completion sound.
C
20P46OUT
Oven lamp, Blower motor and Stirrer motor driving signal. (Square Waveform : 60Hz)
To turn on and off the shut-off relay (RY1). The
Square waveform voltage is delivered to the RY1
driving circuit and relays(RY2,RY3,COOK RELAY)
control circuit.
23
0.1 sec
2 sec
1 sec
+5V
GND
+5V
GND
+5V
GND
200µsec.
T
200µsec.
R-25JT
Pin No.SignalI/ODescription
21P45OUTDigit selection signal.
The relation between digit signal and digit are as
follows:
Digit signal Digit
P42..................... 1st.
P43....................2nd.
P44.....................3rd.
P45.....................4th.
Normally, one pulse is output in every ß period,
and input to the grid of the light-emitting diode.
22-24P44-P42OUT
Digit selection signal.
Signal similar to P45.
25INT1IN
Signal synchronized with commercial power source frequency.
This is basic timing for all time processing of LSI.
26INT0INConnected to GND through resistor.
27RESETIN
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.
28P71OUTMemory (EEPROM) clock output.
29P70IN/OUTMemory (EEPROM) data input/output.
30XININ
Internal clock oscillation frequency setting input.
The internal clock frequency is set by inserting the ceramic filter oscillation circuit with
respect to XOUT terminal.
31XOUTOUT
Internal clock oscillation frequency control output.
Output to control oscillation input of XIN.
32VSSINConnected to GND.
33P27IN
Signal coming from touch key.
When either one of G-12 line keys on key matrix is touched, a corresponding signal out of
P30, P31, P32, P33, P34 will be input into P27. When no key is touched, the signal is held
at "L" level.
34P26IN
Signal similar to P27.
When either one of G-11 line keys on key matrix is touched, a corresponding signal will be
input into P26.
35P25IN
Signal similar to P27.
When either one of G-10 line keys on key matrix is touched, a corresponding signal will be
input into P25.
36P24IN
Signal similar to P27.
When either one of G-9 line keys on key matrix is touched, a corresponding signal will be
input into P24.
37-38P23-P22OUTTerminal not used.
39-40P21-P20OUT
Segment data signals.
The relation between signals and indicators are as follows:
SignalSegmentSignalSegment
P21,P20 ..........1P05,P04 .............7
P17.P16 ..........2P03,P02 .............8
P15,P14 ..........3P01,P00 .............9
P13,P12 ..........4
P11,P10 ..........5
P07,P06 ..........6
ß(60Hz)
P42
P43
P44
P45
ß(60Hz)
16.7 msec
H
L
+5V
GND
H : +5V
L : GND
+5V
GND
24
Pin No.SignalI/ODescription
R-25JT
41-48P17-P10OUT
Segment data signal.
Signal similar to P21.
49-56P07-P00OUT
Segment data signal.
Signal similar to P21.
57-59P37-P35OUTTerminal not used.
60P34OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P27, P26, P25 and P24
terminals while one of G4 line keys on key matrix is touched.
61P33OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P27, P26, P25 and P24
terminals while one of G5 line keys on key matrix is touched.
62P32OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P27, P26, P25 and P24
terminals while one of G6 line keys on key matrix is touched.
63P31OUTKey strobe signal.
Signal applied to touch-key section. A pulse signal is input to P27, P26, P25 and P24
terminals while one of G7 line keys on key matrix is touched.
64P30OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P27, P26, P25 and P24
terminals while one of G8 line keys on key matrix is touched.
2-2 Memory IC (IC2)
X24C02P is a 2K-bit, serial memory, enabling CMOS to be erased/written electrically. This memory is constructed with 256
registers x 8bits, enabling individual access, read and write operations to be performed. Details of input/output signal for IC2 are
as shown in the following diagram.
FUNCTIONAL DIAGRAM
(3) Vcc
A0
A1
A2
VSS
TOP VIEW
1
2
3
4
(4) Vss
(5) SDA
VCC
8
TEST
7
SCL
6
SDA
5
(6) SCL
START
STOP
LOGIC
SLAVE ADDRESS
REGISTER
COMPARATOR
Dout
ACK
LOAD
R/W
CONTROL
LOGIC
WORD
ADDRESS
COUNTER
START CYCLE
INC
PIN
Figure T-3 Relation between Pin Nos, and Signals
Pin No.SignalI/ODescription
1-3A0-A2INConnected to +5V.
4VSSINConnected to GND.
5SDAIN/OUTSerial data input/output : input/outputs data to IC1.
6SCLIN
Clock signal input : input/outputs sireal data at every one pulse.
7TESTINConnected to GND.
8VCCINConnected to +5V.
XDEC
5
64
1
3
CK
H.V. GENERATION
TIMING
& CONTROL
2
E PROM
256 x 8
64
YDEC
8
DATA REGISTER
Dout
25
R-25JT
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 all 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.
approx. 1M ohm
2. Shapes of Electronic Components
Transistor
DTA123ES
DTB143ES
1
2
3
IC
KIA7805PI
C
E
B
DTD143ES
KRA101M
KRC101M
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).
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 long enough
that they may be separated from each other. For those
models, 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 activates 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 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
activates 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
sensor-related controls of the touch control panel by
using the dummy resistor(s).
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 connectors 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.
26
R-25JT
PROCEDURE FOR CHECKING/CLEARING
SERVICE COUNTS OF MICROWAVE OVEN
The following procedure enables the servicer to obtain the
total using times (cook cycles) since the microwave oven is
purchased and the total operation time (hours) since the
microwave oven is purchased. The maximum capacity of
the total using is 999,999 times, and the maximum capacity
of total operation time is 999,999 hours.
1) Practice for checking total using times (Ex. 345678
times).
... Flashing / ... 0.1sec BUZZER
PADDISPLAYINDICATOR TONE
(Door close).
.
CHECK.CHECK No.
CHECK82 68CHECK
(user total count)
SIGNAL
SIGNAL
DOUBLE34 56
QUANTITY
1 (No 1)1No.
(after 1 sec.)34 56
2 (No 2)2No.
(after 1 sec.)78
CHECK.
2) Practice for checking total operation time (Ex. 4567
hours).
PADDISPLAYINDICATOR TONE
(Door close).
CHECK.CHECK No.
CHECK82 68CHECK
(service total count upper figure)
3456XX
(service total count upper figure)
(service total count lower figure)
... Flashing / ... 0.1sec BUZZER
.
(user total count)
3) Practice for inputting total using times (Ex. 310000 times).
... Flashing / ... 0.1sec BUZZER
PADDISPLAYINDICATOR TONE
(Door close).
CHECK.CHECK No.
CHECK82 68CHECK
SIGNAL
SIGNAL
DOUBLE34 56
QUANTITY
22No.
(after 1 sec.)78
11No.
(after 1 sec.)34 56
SET0
3,1,0,031 00x 4
SET31 00
22No.
(after 1 sec.)78
SET0
00
SET0
CHECK.
(user total count)
(service total count upper figure)
3456XX
(service total count lower figure)
XXXX78
(service total count 310000 set)
.
4) Practice for inputting total operation time (Ex. 1234
hours).
... Flashing / ... 0.1sec BUZZER
PADDISPLAYINDICATOR TONE
(Door close).
CHECK.CHECK No.
CHECK82 68CHECK
(user total count)
SIGNAL
SIGNAL
DOUBLE34 56
QUANTITY(service total count upper figure)
3456XX
99No.
.
SIGNAL
SIGNAL
DOUBLE34 56
QUANTITY
9 (No 9)9No.
(after 1 sec.)45
0 (No 0)0No.
(after 1 sec.)67
CHECK.
(service total count upper figure)
3456XX
(Total operation time upper figure)
(Total operation time lower figure)
(after 1 sec.)45
SET0
1,212x 2
SET12
010No.
(after 1 sec.)67
SET0
3,434x 2
SET34
(Total operation time 1234 hours set)
CHECK.
27
R-25JT
5) Practice for cancelling total using times and total operation
time (user and service) and all other counter.
#1 : No key entry signal.
#2 : To set -B, touch the selectapower key twice.
#3 : Ex. defrost is paused after 50% of cooking time has lapsed when 5
key is entered, otherwise it is paused at the end of each stage.
KEYDISPLAYPAUSE
00End of each stage
11After 10% of total cooking time is passed
:::
99After 90% of total cooking time is passed
STARTAThere is no pause
2) To check the constants of Express defrost.
" ": Flicker / : 0.1 sec BUZZER
PADDISPLAYINDICATORTONE
.
CHECK."No." CHECK
EXPRESS DEFROST0.20DEF
( A )
20
( +-B )
P - 40
( PL )
0.13
( A )
30
( +-B )
P - 30
( PL )
5
( pause time )
P - 20
( PL )
( repeat )
CHECK.
3) To set user counts
Practice for inputting total number of using times (Ex.
3100 times), and using times of Memory 1 (Ex. 100
times).
" ": Flicker / : 0.1 sec BUZZER
PADDISPLAYINDICATORTONE
(Door close).
.
CHECK.CHECK No.
CHECK82 68CHECK
(user total count)
DOUBLE QUANTITY
SIGNAL
SET0
3,1,0,031 00x 4
SET31 00
(user total count 3100 set)
#A11No.
(after 1 sec.)1 32
(memory 1 count)
SET0
1,0,01 00x 3
SET1 00
(memory 1 count 100 set)
CHECK.
NOTE:
1 : To input using times of other memory, touch necessary Memory key
at above step #A.
2 : To input using times of manual cooking, touch SELECTATIME key
at above step #A.
3 : To input using times of Express Defrost, touch EXPRESS
DEFROST key at above step #A.
28
MEMORY READJUSTMENT PROCEDURE
1. To set the standard voltage
When the IC2 is changed in the control unit, the standard voltage must be set again for power supply check.
The power supply must be set 230V within ± 1V, and 230V connector in control unit installed.
PAD ORDERDISPLAYTONE
(230V power)
(Door close)(BLANK)
(Plug in).
SIGNAL.
DOUBLE.
SET.
All
CHECK 0633indicators
ON
(plug off)(BLANK)
NOTE :
1. This procedure must be performed within 1 minute.
2. When IC2 malfunctions the unit does not function normally (correct cooking data is not output, data is not stored
correctly in memory, etc.).
3. Initialization of memory after repairing the touch control panel.
R-25JT
After repairing the touch control panel, reset all counters to 0 (including service counter). Make sure that the constant which
is stated on page 22 (fig.2) has been memorized. If it mismatches, input the constant according to "EXPRESS DEFROST"
on page 28.
29
R-25JT
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:
1. Disconnect the power supply cord.
2. Make sure that a definite “click” can be heard when the
microwave oven door is unlatched. (Hold the door in a
closed position with one hand, then pull the door
release lever with the other, this causes the latch leads
to rise, it is then possible to hear a “click” as the door
switches operate.)
3. Visually check the door and cavity face plate for damage
(dents, cracks, signs of arcing etc.).
Carry out any remedial work that is necessary before
operating the oven.
Do not operate the oven if any of the following conditions
exist;
Avoid possible exposure to microwave energy. Please follow the instructions below before
operating the oven.
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 two high voltage capacitors 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, High voltage rectifier assembly and High
voltage wire.
2) Hot parts:
Oven lamp, Magnetron, High voltage transformer,
1. Door does not close firmly.
2. Door hinge, support or latch hook is damaged.
3. The door gasket or seal is damaged.
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.
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.
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)
Blower fan blade, Blower fan motor, Switches, Switch
levers, Antenna motor and Sirrer antennas.
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, REAR CABINET AND POWER SUPPLY CORD REMOVAL
To remove the components, procedure as follows.
1. Disconnect the power supply cord.
2. Remove the screws from the rear and along side the
edge of the outer case.
3. Slide the case back about 1 inch (3 cm) to free it from the
oven cavity.
4. Lift entire case from the unit.
5. DISCHARGE TWO HIGH VOLTAGE CAPACITORS
BEFORE TOUCHING ANY OVEN COMPONENTS OR
WIRING.
6. Now, outer case is free.
To remove rear cabinet and power supply cord:
7. Remove the screws holding the rear cabinet to the oven
cavity and blower motor.
30
R-25JT
Upper magnetron
Upper fin
Tab
Thermistor
angle
Magnetron
thermistor
8. Remove the one (1) screws holding the switch mounting
angle to the rear cabinet and release the switch mounting
angle from the rear cabinet.
9. Disconnect the power supply cord from the fuse holder.
10.Remove the one (1) screws holding the grounding wire
of power supply cord to the oven cavity.
11.Remove the rear cabinet with the power supply cord
POWER TRANSFORMERS (1) AND/OR (2) REMOVAL
1. Disconnect the power supply cord and then remove
outer case and rear cabinet, referring to "OUTER CASE,
REAR CABINET AND POWER SUPPLY CORD
REMOVAL".
2. Open the oven door and block it open.
3. Discharge two high voltage capacitors.
4. Disconnect wire leads of power transformers (1) and/or
(2) from magnetrons (1) and/or (2).
5. Remove the wire leads of power transformers from the
wire holder.
6. Pull out the wire leads of power transformers from the
tube.
MAGNETRONS (1) AND/OR (2) REMOVAL
from the oven cavity.
12.Loosen the tab of the cord bushing, and remove the
power supply cord with the cord bushing from the rear
cabinet.
13.Remove the cord bushing from the power supply cord,
14.Now, the power supply cord and rear cabinet are free.
7. Disconnect wire leads of power transformers (1) and/or
(2) from high voltage capacitors (1) and/or (2).
8. Disconnect the high voltage wire lead(s) from power
transformers (1) and/or (2).
9. Disconnect the main wire harness from power
transformers (1) and/or (2).
10.Remove two (2) screws holding each power transformer
(1) and/or (2) to base plate.
11.Remove the power transformers (1) and/or (2) from base
plate.
12.Now, power transformers (1) and/or (2) are free.
Removal
1. Disconnect the power supply cord and then remove
outer case and rear cabinet, referring to "OUTER CASE,
REAR CABINET AND POWER SUPPLY CORD
REMOVAL".
2. Open the oven door and block it open.
3. Discharge two high voltage capacitors.
4. Remove the two (2) screws holding magnetron exhaust
duct to upper and lower waveguide.
5. Remove the magnetron exhaust duct from oven cavity.
6. Disconnect wire leads from magnetrons (1) and/or (2).
7. Disconnect magnetron thermistor from the connector of
the stop switch harness.
8. Remove the one (1) screw holding the thermistor angle
MAGNETRON THERMISTOR REPLACEMENT
Removal
1. Disconnect the power supply cord and then remove
outer case and rear cabinet, referring to "OUTER CASE,
REAR CABINET AND POWER SUPPLY CORD
REMOVAL".
2. Open the oven door and block it open.
3. Discharge two high voltage capacitors.
4. Remove the upper magnetron from the upper waveguide
flange, referring to "MAGNETRON (1) AND /OR (2)
REMOVAL".
5. Now, the upper magnetron with the magnetron thermistor
should be free.
6. Remove the thermistor angle from the upper magnetron
by pulling out.
7. Straighten the tab of the magnetron thermistor angle
8. Remove the magnetron thermistor from the thermistor
9. Now, the magnetron thermistor is free.
holding the magnetron thermistor.
angle.
to the upper magnetron.
9. Remove the four (4) screws holding each magnetron (1)
and/or (2) to upper and/or lower waveguide. When
removing the screws, hold the magnetron to prevent it
from falling.
10.Remove the magnetrons (1) and/or (2) from upper and/
or lower waveguide with care so magnetron antenna is
not hit by any metal object around antenna.
11.Pull out the thermistor angle from the upper magnetron.
12.Now, the magnetrons (1) and/or (2) are free.
CAUTION: WHEN REPLACING MAGNETRON, BE SURE
THE R.F. GASKET IS IN PLACE AND MOUNTING SCREWS ARE TIGHTENED SECURELY.
Re-install
1. Install the magnetron thermistor to the thermistor angle
as shown in Figure C-1.
Figure C-1. Magnetron thermistor installation
2. Hold the magnetron thermistor to the thermistor angle by
bending the tab of the thermistor angle.
3. Insert the thermistor angle between the 2nd. fin and 3rd.
fin from the upper fin of the upper magnetron and push
it until the thermistor angle stops.
31
R-25JT
NOTE: The magnetron thermistor should be between the
upper fin and the 2nd. fin.
4. Re-install the upper magnetron to the upper waveguide
flange with four (4) screws.
5. Re-install the thermistor angle to the upper waveguide
flange with one (1) screw.
6. Re-install the magnetron exhaust duct to the upper and
lower waveguide flanges with two (2) screws.
7. Route the thermistor harness under the magnetron
temperature fuse.
8. Connect the thermistor harness to the stop switch
harness.
9. Connect the wire leads to the upper magnetron, referring
to the pictorial diagram.
10.Re-install the power supply cord, rear cabinet and outer
case cabinet to the oven by reversing the procedures of
"OUTER CASE, REAR CABINET AND POWER SUPPLY
CORD REMOVAL".
HIGH VOLTAGE CAPACITOR AND HIGH VOLTAGE RECTIFIER ASSEMBLY REMOVAL
1. Disconnect the power supply cord and then remove
outer case and rear cabinet , referring to "OUTER CASE,
REAR CABINET AND POWER SUPPLY CORD
REMOVAL".
2. Open the oven door and block it open.
3. Discharge two high voltage capacitors.
4. Remove two (2) screws holding ground side terminals of
high voltage rectifier assembly to the capacitor holder
and oven cavity.
5. Disconnect all wire leads from the high voltage capacitor.
6. Disconnect wire leads of high voltage rectifier assembly
from the power transformers (1) and/or (2).
Now, high voltage assembly is free.
7. Remove the three (3) screws holding the blower motor to
the top of oven cavity, the chassis support and air duct.
8. Remove two (2) screws holding the capacitor holder to
oven cavity.
Now, the capacitors (1), (2) and the high voltage rectifier
assembly are free.
CAUTION:
1. DISCHARGE THE TWO HIGH VOLTAGE CAPACITOR
BEFORE TOUCHING ANY OVEN COMPONENTS OR
WIRING.
2. DO NOT REPLACE ONLY THE HIGH VOLTAGE
RECTIFIER. IF IT IS DEFECTIVE, REPLACE THE
HIGH VOLTAGE RECTIFIER ASSEMBLY.
3. WHEN REPLACING THE HIGH VOLTAGE RECTIFIER
ASSEMBLY AND THE HIGH VOLTAGE CAPACITOR,
THE GROUND SIDE TERMINAL OF THE HIGH
VOLTAGE RECTIFIER MUST BE SECURED FIRMLY
WITH A GROUNDING SCREW.
BLOWER MOTOR AND BLOWER MOTOR TEMPERATURE FUSE REMOVAL
1. Disconnect the power supply cord and then remove
outer case and rear cabinet, referring to "OUTER CASE,
REAR CABINET AND POWER SUPPLY CORD
REMOVAL".
2. Open the oven door and block it open.
3. Discharge two high voltage capacitors.
4. Disconnect the wire leads from the blower motor and
blower motor temperature fuse.
5. Remove the one (1) screw holding the blower motor to
the oven cavity.
STIRRER MOTORS (UPPER AND LOWER) REMOVAL
UPPER
1. Disconnect the power supply cord and then remove
outer case, referring to "OUTER CASE, REAR CABINET
AND POWER SUPPLY CORD REMOVAL".
2. Open the oven door and block it open.
3. Discharge two high voltage capacitors.
4. Disconnect the wire leads from the stirrer motor (upper).
5. Remove the one (1) screw holding the stirrer motor
(upper) to the oven cavity.
6. Turn and lift up the stirrer motor (upper).
7. Now, the stirrer motor (upper) is free.
LOWER
1. Disconnect the power supply coed.
6. Remove the one (1) screw holding the blower motor to
the chassis support.
7. Remove the one (1) screw holding the air duct to the
blower motor.
8. Remove the blower motor from the oven cavity.
9. Remove the two (2) screws holding the blower motor
temperature fuse to the blower motor.
10.Now, the blower motor and blower motor temperature
fuse are free.
2. Remove the stirrer motor cover by snipping off the
material in four portions.
3. Where the portions have been snipped off bend the
portions flat. No sharp edge must be evident after
removal of the stirrer motor cover.
4. Disconnect the wire leads from the stirrer motor (lower).
5. Remove the one (1) screw holding the stirrer motor
(Lower) to the oven cavity.
6. Now, the stirrer motor (lower) is free.
7. After replacement use one (1) screw to fit the stirrer
motor cover. (This screw has been fitted to the base plate
near the stirrer motor cover beforehand.)
HOW TO RELEASE THE POSITIVE LOCK® CONNECTOR.
Procedure
1. Disconnect the power supply cord and then remove
outer case and rear cabinet, referring to "OUTER CASE,
REAR CABINET AND POWER SUPPLY CORD
32
R-25JT
REMOVAL".
2. Open the oven door and block it open.
3. Discharge two high voltage capacitors.
4. Pushing the lever of positive lock® connector, pull down
the connector from the terminal.
5. Now, the connector is free.
Note: If the positive lock® has a insulation sleeve, first
remove it. If you do not, you can not push the lever
of positive lock®.
CAUTION: THE POSITIVE LOCK® TERMINAL CAN NOT
BE REMOVED BYJUST PULLING ON IT. THE
LOCK LEVER MUST BE RELEASED TO REMOVE THE CONNECTOR FROM THE TERMINAL.
CONTROL PANEL ASSEMBLY AND CONTROL UNIT REMOVAL
CONTROL PANEL ASSEMBLY REMOVAL
The complete control panel should be removed for replacement of components. To remove the control panel, proceed
as follows:
1. Disconnect the power supply cord.
2.
Remove the air intake filter assembly from the base plate.
3. Remove two (2) screws holding the control panel to the
base plate.
4. Pull down the control panel and remove it forward.
5. Disconnect connectors (A), (B), (D), (H), wiring from tab
terminal 1 and 2 and wiring from RY1 and RY2.
6. Now the control panel assembly is free.
CAUTION FOR TOUCH CONTROL PANEL REMOVAL
1)
Hold the lower end (Position A, Fig. 1) of the touch control
panel assembly firmly while sliding it down and toward you.
DO NOT FORCE THE CONTROL UNIT TO SLIDE DOWN
DURING REMOVAL. THIS MAY CAUSE DAMAGE TO
THE CONTROL UNIT BY HITTING THE TAB TERMINALS
LOCATED AT THE FRONT OF THE OVEN CAVITY.
2) If the Touch Control Panel is hard to remove;
(1)Insert a flat head screw driver into space B . (Fig. 1)
(2)Rotate the screwdriver clockwise while holding position
C of the Touch Control Panel. (Fig. 2)
TO AVOID DAMAGE TO TOUCH CONTROL PANEL,
COVER THE TIP OF SCREWDRIVER WITH TAPE.
Fig. 1
TOUCH CONTROL PANEL
SCREW DRIVER
B
B
A
C
Fig. 2
Terminal
Positive lock®
connector
1
Push
Lever
2
Pull down
Figure C-2. How to release the positive lock connector.
Replacement of individual component is as follows:
CONTROL UNIT AND CONTROL PANEL FRAME
(WITH KEY)
7. Remove two (2) screws holding the control panel
mounting angle to the panel frame.
8. Lift up the control panel mounting angle from the panel
frame.
9. Disconnect connector (G) from the control unit by pushing
the hooks of cable holder inwardly.
10.Remove five (5) screws holding the control unit to the
panel frame assembly.
11.Push down the right side two (2) hooks fixing the control
unit to the panel frame assembly, and lift up the control
unit upward.
12.Now, the control unit and control panel frame (with key)
are free.
CAUTION:
When installing the control unit into the control panel
frame:
1. Be careful not to damage any of the components on
the control unit.
2. When inserting key units ribbon cable through the
frame, ensure it is not pinched or bent. Ensure the
control unit is pushed upward to lock into the control
panel frame prior to screwing the control unit into
the frame.
3. Ensure there are not any wires near the varistors, if
the explode, they may damage the wires.
NOTE: 1. Before attaching a new key unit, remove
remaining adhesive on the control panel frame
surfaces completely with a soft cloth soaked in
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 to prevent scratching.
33
R-25JT
VOLTAGE SELECT SWITCH REMOVAL
1. Disconnect the power supply cord and then remove
outer case and rear cabinet, referring to "OUTER CASE,
REAR CABINET AND POWER SUPPLY CORD
REMOVAL".
2. Now, the switch mounting angle should be removed from
the rear cabinet.
3. Remove the two (2) screws and the two (2) nuts holding
the voltage select switches and the switch spacer to the
switch mounting angle.
4. Remove the voltage select switches and the switch
spacer f rom the switch mounting angle.
5. Now, the voltage select switches are free.
DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCHES (1), (2) AND MONITOR
SWITCHES (1), (2) REPLACEMENT
REMOVAL
1. Disconnect the power supply cord and then remove
outer case, referring to "OUTER CASE, REAR CABINET
AND POWER SUPPLY CORD REMOVAL".
2. Open the oven door and block it open.
3. Discharge two high voltage capacitors.
4. Remove outer control panel reffering to "CONTROL
PANEL ASSEMBLY AND CONTROL UNIT REMOVAL".
5. Disconnect all wire leads from the all switches.
6. Remove two (2) screws holding latch hook to oven
flange.
7. Remove latch hook assembly from oven flange.
8. Remove the switch(es) in accordance with following
procedure.
DOOR SENSING SWITCH
Push the two (2) tabs outward and pull switch forwards
to release switch.
MONITOR SWITCHES OR SECONDARY INTERLOCK
SWITCHES
Remove one (1) screw and nut holding two switches
together to latch hook.
8. Now, switch(es) is now free.
RE-INSTALL
1. Re-install the switch(es) in accordance with following
procedure.
DOOR SENSING SWITCH
Mount the door sensing switch in the lower position of
latch hook.
MONITOR SWITCHES
1) Mount the two (2) switches side by side in the top position
of the latch hook.
2) Fasten both switches together to latch hook with one (1)
screw and nut.
SECONDARY INTERLOCK SWITCHES
1) Mount the two (2) switches side by side in the middle
position of the latch hook.
2) Fasten both switches together to latch hook with one (1)
screw and nut.
2. Re-install latch hook assembly and fasten it to oven
flange with two (2) screws.
3. Re-connect all wire leads to all switches, referring to
pictorial diagram. Be careful to ensure proper connection
of the wire leads.
4. Make sure that the monitor switches (1), (2) and all other
switches are operating properly. And check continuity of
the monitor circuit. Refer to chapter "Test Procedure"
and Adjustment procedure.
DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCHES (1), (2) AND MONITOR
SWITCHES (1), (2) ADJUSTMENT
1. Disconnect the power supply cord and then remove
outer case, referring to "OUTER CASE, REAR CABINET
AND POWER SUPPLY CORD REMOVAL".
2. Open the oven door and block it open.
3. Discharge two high voltage capacitors.
If the door sensing switch, secondary interlock switches (1),
(2) and monitor switches (1), (2) do not operate properly due
to a misadjustment, the following adjustment should be
made.
4. Loosen the two (2) screws holding 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 switches (1), (2) are
activated with the door closed. The horizontal position of
the latch hook should be adjusted so that the monitor
switches (1), (2) are activated with the door closed.
6. Secure the screws with washers firmly.
7. Check the operation of all switches. If all switches have
not activated with the door closed, loosen two (2) screws
and adjust the latch hook position.
Door release
lever
Joint lever
Latch lever
Latch head
Latch head
Switch lever A
Monitor switch (2)
Monitor switch (1)
Latch hook
Switch lever B
Secondary interlock
switch (2)
Secondary interlock
switch (1)
Door sensing switch
Switch lever C
Figure C-3. Latch Switch Adjustments
34
R-25JT
After adjustment, check the following.
1. In and out play of door remains less than 0.5mm when in
the latched position.
2. The door sensing switch and secondary interlock switches
(1), (2) interrupt the circuit before the door can be
opened.
DOOR REPLACEMENT
REMOVAL
1. Disconnect the power supply cord and then remove
outer case, referring to "OUTER CASE, REAR CABINET
AND POWER SUPPLY CORD REMOVAL".
2. Open the oven door and block it open.
3. Discharge two high voltage capacitors.
4. Remove the two (2) screws holding each of the upper
and lower oven hinges to the oven cavity.
5. Remove door assembly with upper and lower oven
hinges by pulling it forward.
6. Release upper and lower oven hinges from door
assembly.
7. Now, door assembly is free.
NOTE: When individual parts are replaced, refer to "Door
Disassembly".
RE-INSTALL
1. Insert the upper and lower oven hinges into door hinge
pins.
2. Insert the upper and lower oven hinges with door assembly
into rectangular holes of oven cavity front plate.
3. Make sure that the door is parallel with oven face lines
(left and upper side line) and door latch heads pass
through the latch holes correctly.
4. Fasten upper and lower oven hinges firmly to oven cavity
with two (2) screws on each hinge.
Note: After any service to the door;
(A) Make sure that door sensing switch, secondary
interlock switches (1), (2) and monitor switches (1),
(2) 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.
3. Monitor switches (1), (2) 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.)
After adjustment, make sure of the following:
1. Door latch heads smoothly catch the latch hook through
the latch holes, and the latch head goes through the
center of the latch hole.
2. Deviation of the door alignment from horizontal line of
cavity face plate is to be less than 1.0mm.
3. The door is positioned with its face depressed toward the
cavity face plate.
4. Re-install outer case and 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 door be airtight, 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 of themselves,
indicate a leakage of microwave energy from oven
cavity. If such were the case, your oven could not be
equipped with a vent, the very purpose of which is
to exhaust the vapor-laden air from the oven cavity.
UPPER
OVEN HINGE
OUTER CASE
CABINET
DOOR ADJUSTMENT
Door adjustment is performed with the door properly installed and closed and while the oven hinges are loose.
1. Loosen upper and lower oven hinges with phillips head
screw driver.
2. Adjust the door by moving it vertically so that the top right
hand corner of the door is in line with the top of the control
panel frame assembly.
3. Tighten the upper and lower oven hinge screws.
DOOR DISASSEMBLY
CHOKE COVER REMOVAL
1. Open the door and insert a putty knife (thickness of about
0.5mm) in gap between the choke cover and corner
portion of door panel to free engaging parts. Refer to Fig.
LOWER
LATCH
HEADS
OVEN HINGE
Figure C-4. Door Replacement
C-5.
NOTE: As the choke cover and door panel are engage at 16
places, do not force any perticular part.
2. Remove the choke cover carefully. (If choke cover is
35
R-25JT
broken, replace with a new one.)
DOOR
HANDLE
PUTTY KNIFE
1
BENT
LATCH HEAD
CHOKE COVER
2
UPPER
OVEN HINGE
CHOKE COVER
LOWER
OVEN HINGE
PUTTY KNIFE
BENT
DOOR PANEL
FRONT
Figure C-5. Choke cover
DOOR COMPONENTS REMOVAL
DOOR HANDLE REMOVAL
1. Remove the door assembly from oven cavity, referring to
"DOOR REMOVAL".
2. Place door assembly on a soft cloth with latches facing
up.
3. Remove choke cover from door panel, referring to
"CHOKE COVER REMOVAL".
4. Remove two (2) screws holding the door handle to door.
5. Remove the door handle from door panel.
6. Now, door handle is free.
UPPER AND LOWER LATCH HEADS REMOVAL
7. Remove the door release lever from the door assembly.
8. Remove the three (3) screws holding the joint plate to the
door panel.
9. Release the latch spring from the tab of the joint lever and
joint plate.
10.Release the latch heads from joint lever and joint plate.
11.Now, the latch heads are free.
DOOR CASE REMOVAL
1. Remove the door assembly from oven cavity, referring to
"DOOR REMOVAL".
2. Remove choke cover from door panel, referring to
"CHOKE COVER REMOVAL".
3. Remove door handle from door panel, referring to "DOOR
HANDLE REMOVAL".
4. Bend up four (4) nails of door case.
5. Remove door case from door panel.
6. Now, the door case is free.
DOOR GLASS REMOVAL
7. Remove the four (4) screws holding two (2) outside
window fixing plates to door panel.
8. Now, the door glass is free.
36
R-25JT
1
A
230/208V 60Hz
POWER SUPPLY CORD
BLK
WHT
GRN
NOTE:
THE GROUNDING CONDUCTOR OF THE
POWER SUPPLY CORD HAS BEEN GROUDED
BY POWER SUPPLY CORD FIXING SCREW.
B
THE SCREW MUST BE KEPT ALWAYS TIGHT.
BLK
WHT
C
FUSE&FUSE
BLK
BLK
BLU
WHT
D
BLK
PNK
(UPPER)
STIRRER MOTOR
HOLDER
BLK
2
BRN
FUSE 120˚C
OVEN TEMP.
BLK
2
Y
W
BLK
Y
1
BLK
WHT
L
W
T
H
L
W
LAMP
OVEN
&
SOCKET
OVEN
THERMISTOR (1)
3
WHT
PNK
(Cabnet side)
BRN
2
1
MAGNETRON
THERMISTOR
RED
WHT
MAGNETRON
HIGH VOLTAGE
HICH VOLTAGE COMPONENTS
HIGH VOLTAGE
B.M. TEMP.
FUSE 120˚C
(1)
(UPPER)
White
CAPACITOR
(1)(2)
CAPACITOR
MOTOR
BLOWER
BLK
BLK
FUSE (1) 150˚C
MAGNETRON TEMP.
Case
H.V. RECTIFIER
H.V. RECTIFIER
BLU
RED
RED
Black tape
POWER
POWER
45
NC
(1)
COM
(Cabinet side)
for Control panle
NC
(2)
COM
transformer
NC
(3)
COM
transformer (Oven side)
BLK
BLU
GRY
(LOWER)
STIRRER MOTOR
FUSE (2) 150˚C
BLK
MAGNETRON TEMP.
(2)
(LOWER)
MAGNETRON
Blue
Case
TRANSFORMER
(1)(2)
TRANSFORMER
BLK
G
B
G
RED
PNK
ORG
for front Power
VOLTAGE SELECT SWITCHES
for rear Power
Y
R
R
N
Y
R
B
W
GRY
PNK
L
H
L
Y
RED
U
PNK
ORG
T
W
BRN
6
A
B
C
D
E
F
G
H
MONITOR
SWITCH (2)
(OVEN SIDE)
MONITOR
SWITCH (1)
(CABINET SIDE)
COMCOM
E
GRY
BLU
GRY
NO
BLK
GRY
GRY
NC
RED
SECONDARY
(1)(2)
NC
WHT
WHT
SECONDARY
SWITCH (2)
INTERLOCK
(OVEN SIDE)
NO
SWITCH (1)
INTERLOCK
(CABINET SIDE)
(2)
COM
OVEN
WHT
BLU
WHT
(1)
COM
ORG
COM
DOOR
GRN
NO
SENSING
SWITCH
GRN
BLK
GRN
ORG
CN-B
123
IC
PANEL
C
TOUCH CONTROL
N
RED
CN-H
123
CN-B
I
G
RED
RED
WHT
CN-H
RED
BLK
CN-A
1234567
SP1
RY2(1)
RY3(2)
TAB2
BLK
BLK
BLK
TAB1
RED
YLW
C
N
BLK
PNK
RED
T1
RY1
I
A
BLK
WHT
RED
2
3
1
THERMISTOR (2)
GRN
Figure S-1. Pictorial Diagram
F
G
H
1
2
3
37
45
6
R-25JT
1
A
B
LIGHT EMITTING DIODE
C
ONDEF.NO.X 2CHECK
VC
D
Q2
E
2
3
1
Q1 KIA7805PI
HZ12B1
ZD1
DTA123ES
6.8k
R65
R66
+
C7
4.7k
C4 0.1µ/50v
C3 47µ/10v
–
C2 0.1µ/50v
F
C1 2200µ/25v
–
+
D2
D1-D4
11ES1
D1
T1
G
10G471K
VRS1
D3 D4
10G471K
VRS2
1
2
3
4
5
6
7
8
9
LED1
10
11
12
13
R3 4.7k
HZ4A2
ZD2
C64 5.6k
R2 470 R1 470
d
2
IF NOT SPECIFIED, 0.01µ / 16v
IF NOT SPECIFIED, 1SS270A
7- 1XCBWW30P08000Screw : 3mm x 8mm2AB
7- 2XBPSD30P28KS0Screw : 3mm x 28mm2AA
7- 3XNESD30-24000Nut : 3mm x 2.4mm4AA
7- 4LX-BZA130WRE0Special screw1AD
7- 5LX-BZA116WRE0Special screw2AD
7- 6XBPWW40P04000Screw : 4mm x 4mm4AB
7- 7XBTWW40P06000Screw : 4mm x 6mm1AA
42
R-25JT
REF. NO.PART NO.DESCRIPTIONQ'TYCODE
7- 8LX-BZA125WRE0Special screw2AB
7- 9LX-CZA038WRE0Special screw2AA
7-10LX-EZA004WRE0Special screw2AA
7-11XOTSD40P06000Screw : 4mm x 6mm1AA
7-12LX-NZ0082WRE0Special nut1AA
7-13XOTSD40P10000Screw : 4mm x 10mm2AA
7-14XHPSD50P08000Screw : 5mm x 8mm8AB
7-15XHPSD40P05000Screw : 4mm x 5mm2AA
7-16XHTSD40P08RV0Screw : 4mm x 8mm11AA
7-17XOTSD40P12000Screw : 4mm x 12mm5AA
7-18XOTWW40P10000Screw : 4mm x 10mm14AB
7-19XCPSD40P10000Screw : 4mm x 10mm1AC
7-20XCPSD40P08000Screw : 4mm x 8mm1AA
7-21XFPSD40P08K00Screw : 4mm x 8mm1AA
7-22XOTWW40P08000Screw : 4mm x 8mm6AB
7-23PSPA-A101WRE0Special washer4AB
7-24XCPSD30P06000Screw : 3mm x 6mm2AA
7-25LX-BZA064WRE0Special screw1AA
7-26XBPSD30P50K00Screw : 3mm x 50mm2AC
7-27XFPSD50P12KS0Screw : 5mm x 12mm4AA
7-28XFTSD40P08000Screw : 4mm x 8mm1AA
7-29XTPSD40P08000Screw : 4mm x 8mm2AA
7-30XWWSD50-06000Washer : 5mm x 0.6mm2AA
7-31XONSC40P10000Screw : 4mm x 10mm1AA
7-32LX-BZA110WRE0Special screw4AC
7-33XOTSC40P12000Screw : 4mm x 12mm7AA
7-34XJPSD40P10000Screw : 4mm x 10mm2AA
7-35XNASD40-20000Square nut1AB
7-36LANGQ0382WRM0Special washer1AC
HOW TO ORDER REPLACEMENT PARTS
To have your order filled promptly and correctly, please furnish the following information.
1. MODEL NUMBER2. 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
FPADBA313WRK0
PACKING AND ACCESSORIES
DOOR PROTECTION SHEET
SPADPA552WRE0
DOOR PAD
SPADF0341WRE0
6-2 MENU STICKER
WRAP COVER
BOTTOM PAD ASSEMBLY
FPADBA314WRK0
6-1 INSTRUCTION MANUAL
PACKING CASE
SPAKCD288WRE0
* Not replaceable items.
43
R-25JT
1
6-8
2-5
A
7-31
7-22
B
7-22
7-1
1-16
1-2
C
4-18
4-12
1-13
7-35
4-1
D
4-24
4-37
4-3
4-4
7-32
4-11
7-12
1-1
7-36
E
4-15
7-23
7-6
7-23
F
4-16
G
2-7
4-38
7-32
7-5
2-5-1
1-7
7-7
2-1
2
2-6
7-22
7-18
6-6
7-15
4-21
x-2
7-34
7-4
4-36
6-14
4-45
4-39
4-2
2-8
4-26
1-14
4-21
7-15
4-34
4-43
6-5
1-14
3
7-22
1-15
7-14
7-16
7-14
A
1
2
A
B
7-34
1-15
7-21
4-31
1-17
6-13
45
OVEN AND CABINET PARTS
4-20
4-23
2-4
7-33
7-26
1-7
4-19
4-10
7-11
B
7-16
4-26
7-28
4-40
4-9
4-17
7-18
1-3
1-3
1-8
4-7
7-18
4-9
1-10
4-26
6-6
A
1
A
2
7-16
4-8
1-9
4-5
4-44
1-11
4-25
4-27
7-16
1-6
4-22
7-16
7-14
1-12
1-12
7-10
7-3
7-27
7-30
7-27
7-30
1-17
4-47
7-2
4-6
4-41
1-11
7-18
1-10
7-18
7-2
7-29
6-10
7-19
4-14
1-11
1-5
7-3
1-9
6-11
4-28
7-16
7-25
7-18
1-4
7-13
7-16
7-18
4-33
7-18
7-20
4-29
4-32
6
7-33
4-30
4-13
7-24
1-16
A
1-6
B
6-12
7-18
4-42
C
D
E
F
G
H
1
4-35
7-17
7-9
7-16
7-17
2
7-9
7-8
2-2
x2
7-8
3
44
2-3
x2
4-46
45
H
6
R-25JT
1
CONTROL PANEL PARTS
A
6-15
B
3-2-2
C
2
3-2
3-2-3
3
3-1
3-5
3-7
3-3
45
DOOR PARTS
3-4
3-6
5-22
5-4
6
A
B
C
D
E
F
5-21
5-19
G
5-5
3-2-1
5-13
5-3
5-6
5
5-8
5-2
5-13
5-6
5-1
5-7
5-10
5-9
5-11
5-14
5-11
MISCELLANEOUS
6-3
D
5-20
5-12
5-15
5-18
E
5-16
5-17
F
G
6-9
H
To high voltage capacitor
1
6-7
To power transformer
2
6-16
3
45
6-4
Actual wire harness may be different from illustration.
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.
46
'99 SHARP CORP. (9S2.530E) Printed in U.S.A
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