R-55TS-F
SERVICE MANUAL
SY517R55TSPF/
TOASTER OVEN WITH MICROWAVE
MODEL
R-55TS-F
In the interest of user-safety the oven should be restored to its original
condition and only parts identical to those specified should be used.
WARNING TO SERVICE PERSONNEL: Microwave ovens contain circuitry capable of producing very high voltage and
current, contact with following parts may result in a severe,
possibly fatal, electrical shock. (High Voltage Capacitor, High
Voltage Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..)
TABLE OF CONTENTS
Page
PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO
AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY ................... INSIDE FRONT COVER
BEFORE SERVICING ...................................................................................................... INSIDE FRONT COVER
WARNING TO SERVICE PERSONNEL ................................................................................................................ 1
MICROWAVE MEASUREMENT PROCEDURE ................................................................................................... 2
FOREWORD AND WARNING ............................................................................................................................... 3
PRODUCT SPECIFICATIONS .............................................................................................................................. 4
GENERAL INFORMATION ................................................................................................................................... 4
OPERATION .......................................................................................................................................................... 6
TROUBLESHOOTING GUIDE ............................................................................................................................ 11
TEST PROCEDURE ............................................................................................................................................ 13
TOUCH CONTROL PANEL ................................................................................................................................. 21
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ................................................................ 27
PICTORIAL DIAGRAM ........................................................................................................................................ 34
CONTROL UNIT CIRCUIT .................................................................................................................................. 35
PRINTED WIRING BOARD ................................................................................................................................. 36
PARTS LIST ........................................................................................................................................................ 37
PACKING AND ACCESSORIES ......................................................................................................................... 41
SHARP CORPORATION
This document has been published to be used for after
sales service only.
The contents are subject to change without notice.
R-55TS-F
PRECAUTIONS TO BE OBSERVED BEFORE AND
DURING SERVICING TO AVOID POSSIBLE
EXPOSURE TO EXCESSIVE MICROWAVE ENERGY
(a) Do not operate or allow the oven to be operated with the door open.
(b) Make the following safety checks on all ovens to be serviced before activating the
magnetron or other microwave source, and make repairs as necessary: (1) interlock
operation, (2) proper door closing, (3) seal and sealing surfaces (arcing, wear, and other
damage), (4) damage to or loosening of hinges and latches, (5) evidence of dropping or
abuse.
(c) Before turning on microwave power for any service test or inspection within the microwave
generating compartments, check the magnetron, wave guide or transmission line, and
cavity for proper alignment, integrity, and connections.
(d) Any defective or misadjusted components in the interlock, monitor, door seal, and
microwave generation and transmission systems shall be repaired, replaced, or adjusted
by procedures described in this manual before the oven is released to the owner.
(e) A microwave leakage check to verify compliance with the Federal Performance Standard
should be performed on each oven prior to release to the owner.
BEFORE SERVICING
Before servicing an operative unit, perform a microwave emission check as per the Microwave
Measurement Procedure outlined in this service manual.
If microwave emissions level is in excess of the specified limit, contact SHARP ELECTRONICS
CORPORATION immediately @1-800-237-4277.
If the unit operates with the door open, service person should 1) tell the user not to operate the oven
and 2) contact SHARP ELECTRONICS CORPORATION and Food and Drug Administration's
Center for Devices and Radiological Health immediately.
Service personnel should inform SHARP ELECTRONICS CORPORATION of any certified unit
found with emissions in excess of 4mW/cm2. The owner of the unit should be instructed not to use
the unit until the oven has been brought into compliance.
R-55TS-F
WARNING TO SERVICE PERSONNEL
Microwave ovens contain circuitry capable of producing very high voltage and current, contact with
following parts may result in a severe, possibly
fatal, electrical shock.
(Example)
High Voltage Capacitor, High Voltage Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..
Read the Service Manual carefully and follow all
instructions.
Don't Touch !
Danger High Voltage
When the testing is completed,
1. Disconnect the power supply cord, and then remove
outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Reconnect the leads to the primary of the power
transformer.
5. Reinstall the outer case (cabinet).
6. Reconnect the power supply cord after the outer case is
installed.
7. Run the oven and check all functions.
Before Servicing
1. Disconnect the power supply cord
outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
, and then remove
WARNING:RISK OF ELECTRIC SHOCK.
DISCHARGE THE HIGH-VOLTAGE
CAPACITOR BEFORE SERVICING.
After repairing
The high-voltage capacitor remains charged about 60
seconds after the oven has been switched off. Wait for 60
seconds and then short-circuit the connection of the highvoltage capacitor (that is the connecting lead of the highvoltage rectifier) against the chassis with the use of an
insulated screwdriver.
1. Reconnect all leads removed from components during
testing.
2. Reinstall the outer case (cabinet).
3. Reconnect the power supply cord after the outer case is
installed.
4. Run the oven and check all functions.
Whenever troubleshooting is performed the power supply
must be disconnected. It may, in some cases, be necessary
to connect the power supply after the outer case has been
removed, in this event,
1. Disconnect the power supply cord, and then remove
outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the leads to the primary of the power
transformer.
5. Ensure that the leads remain isolated from other
components and oven chassis by using insulation tape.
6. After that procedure, reconnect the power supply cord.
Microwave ovens should not be run empty. To test for the
presence of microwave energy within a cavity, place a cup
of cold water on the oven turntable, close the door and set
the power to HIGH and set the microwave timer for two (2)
minutes. When the two minutes has elapsed (timer at zero)
carefully check that the water is now hot. If the water
remains cold carry out Before Servicing procedure and reexamine the connections to the component being tested.
When all service work is completed and the oven is fully
assembled, the microwave power output should be checked
and a microwave leakage test should be carried out.
1
R-55TS-F
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 and the primary interlock relay do turn the oven OFF before any door movement.
NOTE: After servicing, record data on service invoice and microwave leakage report.
2
R-55TS-F
SERVICE MANUAL
PRODUCT DESCRIPTION
TOASTER OVEN WITH MICROWAVE
R-55TS-F
GENERAL INFORMATION
FOREWORD
This Manual has been prepared to provide Sharp Electronics Corp.
Service Personnel with Operation and Service Information for the
SHARP TOASTER OVEN WITH MICROWAVE, R-55TS-F.
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.
OPERATION
TROUBLESHOOTING GUIDE AND
TEST PROCEDURE
TOUCH CONTROL PANEL
WARNING
Never operate the oven until the following points are ensured.
(A) The door is tightly closed.
(B) The door brackets and hinges are not defective.
(C) The door packing is not damaged.
(D) The door is not deformed or warped.
(E) There is no other visible damage with the oven.
Servicing and repair work must be carried out only by trained service
personnel.
COMPONENT REPLACEMENT
AND ADJUSTMENT PROCEDURE
WIRING DIAGRAM
DANGER
Certain initial parts are intentionally not grounded and present
a risk of electrical shock only during servicing. Service
personnel - Do not contact the following parts while the
appliance is energized;
High Voltage Capacitor, Power Transformer, Magnetron, High
Voltage Rectifier Assembly, High Voltage Harness;
If provided, Vent Hood, Fan assembly, Cooling Fan Motor.
All the parts marked “*” on parts list are used at voltages more than
250V.
Removal of the outer wrap gives access to voltage above 250V.
All the parts marked “∆” on parts list may cause undue microwave
exposure, by themselves, or when they are damaged, loosened
or removed.
SHARP ELECTRONICS CORPORATION
SHARP PLAZA, MAHWAH,
NEW JERSEY 07430-2135
3
PARTS LIST
R-55TS-F
SPECIFICATION
ITEM
DESCRIPTION
Power Requirements
120 Volts / 8.5 Amperes (Microwave)/ 10.8 Amperes (Grill and Bake)
60 Hertz / Single phase, 3 wire grounded
Power Output
650 watts (IEC TEST PROCEDURE)
Operating frequency of 2450MHz
Upper Heater Power Output
760 Watts
Lower Heater Power Output
510 Watts
Case Dimensions
Width 17-3/4"
Height 11-3/8"
Depth 15-1/8"
Cooking Cavity Dimensions
Width 11-1/4"
Height 5-7/8"
Depth 11-5/8"
0.5 Cubic Feet
Control Complement
NOTE: Internal capacity is calculated by measuring
maximum width, depth and height.
Actual capacity for holding food is less.
Touch Control System
Clock ( 1:00 - 12:59 )
Timer (0 - 95 minutes)
Microwave Power for Variable Cooking
Repetition Rate;
P100 ................................................ Full power throughout the cooking time
P-70 .................................................................... approx. 70% of Full Power
P-50 .................................................................... approx. 50% of Full Power
P-30 .................................................................... approx. 30% of Full Power
P-10 .................................................................... approx. 10% of Full Power
P-0 .................................................... No power throughout the cooking time
Grill cooking (GRILL) ........... Top and bottom grill mode/ Top grill mode only
Bake cooking (BAKE) ................................. 325 - 400˚F temperature control
AUTOMATIC COOKING pads (TOAST pad, SNACKS pad, BAKE pad)
MICRO pad, GRILL pad, BAKE pad, POPCORN pad, REHEAT pad
BEVERAGE pad, FOZEN ENTREES pad, FRESH VEGETABLES pad
EXPRESS DEFROST pad, TIMER/CLOCK pad, STOP/CLEAR pad
MINUTE PLUS/START pad
Oven Cavity Light
Yes
Safety Standard
UL Listed
FCC Authorized
DHHS Rules, CFR, Title 21, Chapter 1, Subchapter J
GENERAL INFORMATION
GROUNDING INSTRUCTIONS
This oven is equipped with a three prong grounding plug. It must be plugged into a wall receptacle that is properly installed
and grounded in accordance with the National Electrical Code and local codes and ordinances.
In the event of an electrical short circuit, grounding reduces the risk of electric shock by providing an escape wire for the
electric current.
WARNING: Improper use of the grounding plug can result in a risk of electric shock.
Electrical Requirements
The electrical requirements are a 120 volt 60 Hz, AC only,
15 or more protected electrical supply. It is recommended that a separate circuit serving only this appliance be provided.
When installing this appliance, observe all applicable codes and ordinances.
A short power-supply cord is provided to reduce risks of becoming entangled in or tripping over a longer cord.
Where a two-pronged wall-receptacle is encountered, it is the personal responsibility and obligation of the customer to
contact a qualified electrician and have it replaced with a properly grounded three-pronged wall receptacle or have a
4
R-55TS-F
grounding adapter properly grounded and polarized. If the extension
cord must be used, it should be a 3-wire, 15 amp. or higher rated cord.
Do not drape over a countertop or table where it can be pulled on by
children or tripped over accidentally.
Grounded
Receptacle Box
3-Pronged
Plug
CAUTION: DO NOT UNDER ANY CIRCUMSTANCES CUT OR REMOVE THE ROUND GROUNDING PRONG FROM THIS
PLUG.
Grounding Pin
3-Pronged Receptacle
OVEN DIAGRAM
9
11
12
17
5
11
16
14
15
1
4
10
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
13 3
6
8
2
Door opening button
3
Push to open door.
Oven door with see-through window
Safety door latches
The oven will not operate unless the door is securely
closed.
Door hinges
Door seals and sealing surfaces
Turntable motor shaft
Removable turntable support
Carefully place the turntable support on the turntable
motor shaft(6) in the center of the oven floor.
Removable turntable
Place the turntable securely on the turntable support.
The turntable will rotate clockwise or
counterclockwise.
Only remove for cleaning or for the foods specified in
this manual.
Top grill heater (top heater)
Bottom grill heater (bottom heater)
The bottom heater is under the cavity floor.
Ventilation openings (rear)
Oven light
It will light when oven is operating or door is open.
Waveguide cover: DO NOT REMOVE.
Rotary dial
Control panel
Time display: 95 minutes
Food label
The food label in English and in Spanish is packed in
the oven. Attach the selected one to the oven top.
Power supply cord
18
TOUCH CONTROL PANEL
7
NOTE:
Some one-touch cooking features such as "MINUTE PLUS" are disabled after three minutes when the oven is not in use. These features
are automatically enabled when the door is opened and closed or the
STOP/ CLEAR pad is pressed.
5
R-55TS-F
OPERATION
DESCRIPTION OF OPERATING SEQUENCE
voltage components are de-energized, the oven lamp
remains on, and the digital read-out displays the time still
remaining in the cook cycle when the door was opened.
7. The monitor switch electrically monitors the operation of
the secondary interlock switch and primary interlock
relay and is mechanically associated with the door so
that it will function in the following sequence.
(1) When the door opens from the closed position, the
primary interlock relay (RY2) and secondary interlock
switch open their contacts. And contacts of the relay
(RY1) remains closed. Then the monitor switch contacts
close.
(2) When the door is closed from the open position, the
monitor switch contacts open first. Then the contacts of
the secondary interlock switch and door sensing switch
close. And contacts of the relay (RY1) open.
If the secondary interlock switch and primary interlock relay
(RY2) fail with the contacts closed when the door is opened,
the closing of the monitor switch contacts will form a short
circuit through the monitor fuse, secondary interlock switch,
relay (RY1) and primary interlock relay (RY2), causing the
monitor fuse to blow.
The following is a description of component functions during
oven operation.
OFF CONDITION
Closing the door activates the door sensing switch and
secondary interlock switch. (In this condition, the monitor
switch contacts are opened.)
When oven is plugged in, 120 volts A.C. is supplied to the
noise filter and the control unit. (Figure O-1).
1. The display will show flashing "88:88".
To set any program or set the clock, you must first touch
the STOP/CLEAR pad. The display will clear, and " : "
will appear.
MICROWAVE COOKING CONDITION
Program desired cooking time by rotating the rotary dial.
Program the power level by touching the MICRO pad.
When the START pad is touched, the following operations
occur:
1. The contacts of relays are closed and components
connected to the relays are turned on as follows.
(For details, refer to Figure O-2)
RELAY
RY-1
RY-2
RY-5
POWER LEVEL P-0 TO P-90 COOKING
When Variable Cooking Power is programmed, the 120
volts A.C. is supplied to the power transformer intermittently
through the contacts of relay (RY-2) which is operated by the
control unit within a 32 second time base. Microwave power
operation is as follows:
CONNECTED COMPONENTS
oven lamp/ turntable motor
power transformer
fan motor
VARI-MODE
P100 (100% power)
2. 120 volts A.C. is supplied to the primary winding of the
power transformer and is converted to about 3.3 volts
A.C. output on the filament winding, and approximately
2000 volts A.C. on the high voltage winding.
3. The filament winding voltage heats the magnetron
filament and the H.V. winding voltage is sent to a voltage
doubler circuit.
4. The microwave energy produced by the magnetron is
channelled through the waveguide into the cavity feedbox, and then into the cavity where the food is placed to
be cooked.
5. Upon completion of the cooking time, the power
transformer, oven lamp, etc. are turned off, and the
generation of microwave energy is stopped. The oven
will revert to the OFF condition.
NOTE: If the thermistor temperature is above
250˚F(120˚C), the circuit to RY5 will be maintained
(by thermistor circuit) to continue operation of
the cooling fan motor until the temperature
drops below 250˚F(120˚C).
6. When the door is opened during a cook cycle, the
monitor switch, door sensing switch, secondary interlock
switch, relay (RY1) and primary interlock relay (RY2) are
activated with the following results. The circuits to the
turntable motor, the cooling fan motor, and the high
ON TIME
32 sec.
OFF TIME
0 sec.
P-70 (approx. 70% power)
24 sec.
8 sec.
P-50 (approx. 50% power)
18 sec.
14 sec.
P-30 (approx. 30% power)
12 sec.
20 sec.
P-10 (approx. 10% power)
6 sec.
26 sec.
P-0 (approx. 0% power)
0 sec.
32 sec.
Note:
The ON/OFF time ratio does not correspond with
the percentage of microwave power, because
approx. 3 seconds are needed for heating of the
magnetron filament.
POWER OUTPUT REDUCTION
If the oven is set more than 20 minutes at MICRO 100%
power level, after the first 20 minutes, the power level will
automatically adjust to 70% to avoid overcooking.
GRILL COOKING CONDITIONS
The oven has two grill cooking conditions. They are the
UPPER HEATER mode and UPPER AND LOWER
HEATERS mode.
6
R-55TS-F
5-2. The oven will continue to function for 30 minutes,
turning the upper heater and the lower heater on
and off, as needed to maintain the selected preheat
temperature. The oven will shutdown completely
after 30 minutes
[BAKE TIME COOKING CONDITION]
UPPER HEATER MODE (GRILL1)
In this mode, the food is cooked by the upper heater. Press
the GRILL pad once and then enter the cooking time by
rotating the rotary dial. When the START pad is pressed,
the following operations occur (Figure O-3):
1. The relays (RY1, RY3 and RY5) are energized.
2. The numbers of the digital read-out start the count down
to zero.
3. Then the upper heater, turntable motor, oven lamp and
fan motor are energized.
4. Now, the food is grilled by the upper heater.
5. Upon completion of the selected cooking time, audible
signal sounds and the contacts of relays (RY1, RY2 and
RY3) are opened, then the upper heater, turntable
motor and oven lamp are de-energized. But the relay
(RY5) stays closed and the fan motor operates until the
thermistor temperature drops below 250˚F(120˚C).
NOTE: Maximum cooking time is 30 minutes.
6. When the preheat temperature is reached, a beep
signal will sound indicating that the holding temperature
has been reached in the oven cavity. Open the door and
place the food to be cooked in the oven. In this time, to
keep the oven temperature, the fan motor will not
operate when the door is opened. When the START pad
is touched, the following operations occur:
7. The numbers on the digital read-out start to count down
to zero.
8. The relays (RY1, RY3, RY4 and RY5) are energized and
the oven lamp, turntable motor and cooling fan motor
are energized.
9. The relays (RY3 and RY4) are energized (if the cavity
temperature is lower than the selected temperature)
and the main supply voltage is applied to the heating
elements to return to the selected cooking temperature.
10.Upon completion of the cooking time, the audible signal
will sound, and oven lamp, turntable motor and cooling
fan motor are de-energized. At the end of the Bake
cooking cycle, if the thermistor temperature is above
250˚F(120˚C), the circuit to RY5 will be maintained (by
the thermistor circuit) to continue operation of the cooling
fan motor until the temperature drops below
250˚F(120˚C), at which time the relay will be deenergized, turning off the fan motor.
NOTE: The actual oven temperature may differ from the
set temperature. Because the oven regulates
the oven temperature by turning the upper and
lower heaters on and off.
UPPER AND LOWER HEATERS MODE (GRILL 2)
In this mode, the food is cooked by both the upper heater
and lower heater. Press the GRILL pad twice and then
enter the cooking time by rotating the rotary dial. When the
START pad is pressed, the following operations occur
(Figure O-4):
1. The relays (RY1, RY3, RY4, and RY5) are energized.
2. The numbers of the digital read-out start the count down
to zero.
3. Then the upper heater, lower heater, turntable motor,
oven lamp and fan motor are energized.
4. Now, the food is grilled by the upper heater and the lower
heater.
5. Upon completion of the selected cooking time, audible
signal sounds and the contacts of relays (RY1, RY3, and
RY4) are opened, then the upper heating elements,
lower heating element, turntable motor and oven lamp
are de-energized. But the relay (RY5) stays closed and
the fan motor operates until the thermistor temperature
drops below 250˚F(120˚C).
NOTE: Maximum cooking time is 30 minutes.
BAKE COOKING CONDITION
1. Program desired oven temperature by touching the
BAKE pad. Enter the cooking time by rotating the rotary
dial. When the START pad is touched, the following
operations occur (Figure O-5):
[PREHEATING CONDITION]
2. The coil of shut-off relays (RY1, RY3, RY4 and RY5) are
energized.
3. The numbers of the digital read-out start the count down
to zero.
4. Then the upper heater, lower heater, turntable motor,
oven lamp and fan motor are energized.
5. When the oven temperature reaches the selected
preheat temperature, the following operations occur:
5-1 The relays (RY3 and RY4) are de-energized by the
control unit temperature circuit and thermistor,
opening the circuit to the heating elements.
7
R-55TS-F
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED
2. CLOCK APPEARS ON DISPLAY
NOTE: " " indicates components with potential above 250V.
NOISE FILTER
TEMPERATURE
FUSE (MAGNETRON)
MAGNETRON
N.O.
COM.
POWER
TRANSFORMER
B3
A5
B5
C1
RY3
N.O.
C2
DOOR
SENSING
SWITCH
RY4
E3
MONITOR SWITCH
FM
CONTROL
UNIT
LOWER
HEAER
A1
RY2
PRIMARY
INTERLOCK
RELAY
RY1
RY5
FAN MOTOR
TURNTABLE MOTOR
COM.
UPPER
HEAER
LINE BYPASS
CAPACITOR
0.0033µF / AC 250V
OVEN LAMP
TTM
LINE BYPASS
CAPACITOR
0.0033µF / AC 250V
LINE CROSS CAPACITOR
1.0µF / AC 250V
NOISE FILTER
RESISTOR 470KΩ 1/2W
OL
COM.
N.O.
A3
CAPACITOR
0.82µF
AC 2100V
THREMISTOR
RECTIFIER
OVEN
THERMOSTAT
N
120V AC
60 Hz
FUSE
15A
NOISE SUPPRESSION COIL
L
THERMAL
CUT-OUT
SECONDARY
INTERLOCK
SWITCH
Figure O-1. Oven Schematic-Off Condition
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED
2. COOKING TIME PROGRAMMED
3. VARIABLE COOKING CONTROL "P100" (100%)
4. "START" PAD TOUCHED
NOISE FILTER
TEMPERATURE
FUSE (MAGNETRON)
MAGNETRON
N.O.
COM.
POWER
TRANSFORMER
B3
A5
DOOR
SENSING
SWITCH
B5
C1
C2
N.O.
RY3
RY4
E3
THREMISTOR
OVEN
THERMOSTAT
SECONDARY
INTERLOCK
SWITCH
Figure O-2. Oven Schematic-Microwave Cooking Condition
8
MONITOR SWITCH
FM
CONTROL
UNIT
LOWER
HEAER
A1
RY2
PRIMARY
INTERLOCK
RELAY
RY1
RY5
FAN MOTOR
TURNTABLE MOTOR
COM.
UPPER
HEAER
LINE BYPASS
CAPACITOR
0.0033µF / AC 250V
OVEN LAMP
TTM
LINE BYPASS
CAPACITOR
0.0033µF / AC 250V
LINE CROSS CAPACITOR
1.0µF / AC 250V
NOISE FILTER
RESISTOR 470KΩ 1/2W
OL
COM.
N.O.
A3
N
120V AC
60 Hz
FUSE
15A
NOISE SUPPRESSION COIL
L
THERMAL
CUT-OUT
CAPACITOR
0.82µF
AC 2100V
RECTIFIER
R-55TS-F
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED
2. "GRILL" TOUCHED ONCE
3. COOKING TIME PROGRAMMED
4. "START" PAD TOUCHED
NOISE FILTER
NOTE: " " indicates components with potential above 250V.
TEMPERATURE
FUSE (MAGNETRON)
N.O.
MAGNETRON
COM.
B1
COM.
POWER
TRANSFORMER
B5
C1
N.O.
C2
DOOR
SENSING
SWITCH
RY4
E3
MONITOR SWITCH
B3
A5
RY3
LOWER
HEAER
FM
CONTROL
UNIT
UPPER
HEAER
A1
RY2
PRIMARY
INTERLOCK
RELAY
RY1
RY5
FAN MOTOR
TURNTABLE MOTOR
TTM
LINE BYPASS
CAPACITOR
0.0033µF / AC 250V
OVEN LAMP
LINE CROSS CAPACITOR
1.0µF / AC 250V
NOISE FILTER
RESISTOR 470KΩ 1/2W
OL
COM.
N.O.
A3
CAPACITOR
0.82µF
AC 2100V
THREMISTOR
RECTIFIER
OVEN
THERMOSTAT
N
120V AC
60 Hz
FUSE
15A
LINE BYPASS
CAPACITOR
0.0033µF / AC 250V
NOISE SUPPRESSION COIL
L
THERMAL
CUT-OUT
SECONDARY
INTERLOCK
SWITCH
Figure O-3. Oven Schematic-GRILL1 Cooking Condition
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED
2. "GRILL" TOUCHED TWICE
3. COOKING TIME PROGRAMMED
4. "START" PAD TOUCHED
NOISE FILTER
TEMPERATURE
FUSE (MAGNETRON)
MAGNETRON
N.O.
COM.
POWER
TRANSFORMER
B3
A5
B5
C1
RY3
N.O.
C2
DOOR
SENSING
SWITCH
RY4
E3
MONITOR SWITCH
FM
CONTROL
UNIT
LOWER
HEAER
A1
RY2
PRIMARY
INTERLOCK
RELAY
RY1
RY5
FAN MOTOR
TURNTABLE MOTOR
COM.
UPPER
HEAER
LINE BYPASS
CAPACITOR
0.0033µF / AC 250V
OVEN LAMP
TTM
LINE BYPASS
CAPACITOR
0.0033µF / AC 250V
LINE CROSS CAPACITOR
1.0µF / AC 250V
NOISE FILTER
RESISTOR 470KΩ 1/2W
OL
COM.
N.O.
A3
CAPACITOR
0.82µF
AC 2100V
THREMISTOR
RECTIFIER
OVEN
THERMOSTAT
N
120V AC
60 Hz
FUSE
15A
NOISE SUPPRESSION COIL
L
THERMAL
CUT-OUT
SECONDARY
INTERLOCK
SWITCH
Figure O-4. Oven Schematic-GRILL2 Cooking Condition
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED
2. "BAKE" TOUCHED ONCE (400˚F)
3. COOKING TIME PROGRAMMED
4. "START" PAD TOUCHED
NOISE FILTER
TEMPERATURE
FUSE (MAGNETRON)
MAGNETRON
N.O.
COM.
POWER
TRANSFORMER
B3
A5
DOOR
SENSING
SWITCH
B5
C1
C2
N.O.
RY3
RY4
E3
MONITOR SWITCH
FM
CONTROL
UNIT
LOWER
HEAER
A1
RY2
PRIMARY
INTERLOCK
RELAY
RY1
RY5
FAN MOTOR
TURNTABLE MOTOR
COM.
UPPER
HEAER
LINE BYPASS
CAPACITOR
0.0033µF / AC 250V
OVEN LAMP
TTM
LINE BYPASS
CAPACITOR
0.0033µF / AC 250V
LINE CROSS CAPACITOR
1.0µF / AC 250V
NOISE FILTER
RESISTOR 470KΩ 1/2W
OL
COM.
N.O.
A3
THREMISTOR
OVEN
THERMOSTAT
N
120V AC
60 Hz
FUSE
15A
NOISE SUPPRESSION COIL
L
THERMAL
CUT-OUT
SECONDARY
INTERLOCK
SWITCH
Figure O-5. Oven Schematic-BAKE Cooking Condition
9
CAPACITOR
0.82µF
AC 2100V
RECTIFIER
R-55TS-F
DESCRIPTION AND FUNCTION OF COMPONENTS
DOOR OPEN MECHANISM
3. If the door is opened, and the primary interlock relay
(RY2) and the secondary interlock switch contact fail to
open, the monitor fuse blows simultaneously with closing
of the monitor switch contacts.
CAUTION: BEFORE REPLACING A BLOWN MONITOR
FUSE, TEST THE DOOR SENSING SWITCH,
RELAY (RY1), PRIMARY INTERLOCK RELAY
(RY2), SECONDARY INTERLOCK SWITCH
AND MONITOR SWITCH FOR PROPER OPERATION. (REFER TO CHAPTER "TEST PROCEDURE").
NOTE: MONITOR FUSE AND MONITOR SWITCH ARE
REPLACED AS AN ASSEMBLY.
The door is opened by pushing the open button on the
control panel, refer to the Figure D-1.
When the open button is pushed, the open button pushes up
the switch lever, and then the switch lever pushes up the
latch head. The latch heads are moved upward and released from latch hook. Now the door will open.
Door
Latch
Heads
Latch Hook
Door Sensing
Switch
TURNTABLE MOTOR
The turntable motor rotates the turntable located on the
bottom of the oven cavity, so that the food on the turntable
is cooked evenly. The turntable may turn in either direction.
Monitor Switch
Switch Lever
COOLING FAN MOTOR
Secondary
Interlock Switch
The cooling fan motor drives a blade which draws external
cool air. This cool air is directed through the air vents surrounding the magnetron and cools the magnetron. This air is
channelled through the oven cavity to remove steam and
vapours given off from the heating foods. It is then exhausted
through the exhausting air vents at the oven cavity.
Figure D-1. Door Open Mechanism
DOOR SENSING AND SECONDARY INTERLOCK
SWITCHES
The secondary interlock switch is mounted in the lower
position of the latch hook and the door sensing switch in the
primary interlock system is mounted in the upper position of
the latch hook. They are activated by the latch heads on the
door. When the door is opened, the switches interrupt the
power to all high voltage components. A cook cycle cannot
take place until the door is firmly closed thereby activating
both interlock switches. The primary interlock system consists of the door sensing switch and primary interlock relay
located on the control circuit board.
THERMAL CUT-OUT 125˚C
This thermal cut-out protects the upper heater against
overheating. If the temperature goes up higher than 257˚F
(125˚C) because the fan motor is interrupted or the ventilation
openings are blocked, the thermal cut-out will open and
line voltages to all electrical parts will be cut off and the
operation of the oven will be stopped. The thermal cut-out
will not resume.
MONITOR SWITCH
OVEN THERMOSTAT
The monitor switch is activated (the contacts opened) by the
latch head on the door while the door is closed. The switch
is intended to render the oven inoperative, by means of
blowing the monitor fuse, when the contacts of the primary
interlock relay (RY2), relay (RY1) and secondary interlock
switch fail to open when the door is opened.
The oven thermostat is located on the top of the oven cavity.
The oven thermostat will open at higher than 302˚F (150˚C).
And the oven thermostat will close at lower than 266˚F
(130˚C).
TEMPERATURE FUSE (MAGNETRON)
The temperature fuse, located near the magnetron, is
designed to prevent damage to the magnetron. If an over
heated condition develops in the magnetron due to cooling
fan failure, obstructed air guide, dirty or blocked air intake,
etc., the temperature fuse will open.
Under normal operation, the temperature fuse remains
closed. However, when abnormally high temperatures are
reached within the oven cavity, the temperature fuse will
open at 302˚F (150˚C), causing the oven to shut down.
Functions:
1. When the door is opened, the monitor switch contacts
close (to the ON condition) due to their being normally
closed. At this time the primary interlock relay (RY2) and
secondary interlock switch are in the OFF condition
(contacts open) due to its being normally open contact
switches. But the contacts of relay (RY1) are closed to
turn on the oven lamp.
2. As the door goes to a closed position, the monitor switch
contacts are first opened and then the door sensing switch
and secondary interlock switch contacts close. At this time,
the contacts of the relay (RY1) and the primary interlock
relay (RY2) are in the OFF condition (contacts open)
UPPER HEATER
The upper heater is located on the top of the oven cavity
assembly. The upper heater sends out heat to cook foods.
10
R-55TS-F
LOWER HEATER
NOISE FILTER
The lower heater is located under the bottom of the oven
cavity assembly. The lower heater sends out heat to cook
foods.
The noise filter prevents the radio frequency interference
that might flow back in the power unit.
TROUBLESHOOTING GUIDE
Never touch any part in the circuit with your hand or an uninsulated tool while the power supply is connected.
When troubleshooting the microwave oven, it is helpful to follow the Sequence of Operation in performing the checks. Many
of the possible causes of trouble will require that a specific test be performed. These tests are given a procedure letter which
will be found in the "Test Procedure "section.
IMPORTANT: If the oven becomes inoperative because of a blown monitor fuse, check the monitor switch, primary
interlock relay (RY2), door sensing switch and secondary interlock switch before replacing the monitor
fuse. If monitor fuse is replaced, the monitor switch must also be replaced. Use part FFS-BA038WRKZ
as an assembly.
IMPORTANT: Whenever troubleshooting is performed with the power supply cord disconnected. It may in, some cases,
be necessary to connect the power supply cord after the outer case has been removed, in this event,
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the leads to the primary of the power transformer.
5. Ensure that the leads remain isolated from other components and oven chassis by using insulation tape.
6. After that procedure, reconnect the power supply cord.
When the testing is completed,
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Reconnect the leads to the primary of the power transformer.
5. Reinstall the outer case (cabinet).
6. Reconnect the power supply cord after the outer case is installed.
7. Run the oven and check all functions.
11
R-55TS-F
CK = Check / RE = Replace
POSSIBLE CASE
AND
DEFECTIVE PARTS
CONDITION
PROBLEM
A B C D E E E F F G H I
Monitor fuse blows when power
cord is plugged into wall outlet.
Monitor fuse blows when the door
is opened.
Oven lamp does not light when
door is opened. (Display operates.)
OFF
CONDITION
Home fuse blows when power cord
is plugged into wall outlet.
"88:88" does not appear in display
when power cord is plugged into wall
outlet.
Display does not operate properly
when STOP/CLEAR pad is pressed.
Oven does not start when the
START pad is pressed. (Display
operates.)
Oven lamp does not light. (Turntable
motor operates.)
COOKING
CONDITION
(COMMON MODE)
Fan motor does not operate. (Oven
lamp lights.)
Turntable motor does not operate.
(Oven lamp lights.)
Oven or electrical parts does not
stop when cooking time is 0 or
STOP/CLEAR pad is pressed.
Oven goes into cook cycle but shuts
down before end of cooking cycle.
Oven seems to be operating but little
or no heat is produced in oven load.
MICROWAVE
COOKING
CONDITION
Oven does not operate properly
during variable cooking condition
except 100% cooking condition.
Function of EXPRESS DEFROST
does not operate properly.
Upper heater does not operate.
GRILL
COOKING
CONDITION
Lower heater does not operate.
Upper and lower heaters do not
operate.
Upper heater does not operate.
Lower heater does not operate.
BAKE
COOKING
CONDITION
I J L M N O O O O O P Q RERERERE CK CK CK
MAGNETRON
POWER TRANSFORMER
H.V. RECTIFIER ASSEMBLY
HIGH VOLTAGE CAPACITOR
OVEN THERMOSTAT
THERMAL CUT-OUT 125˚C
TEMPERATURE FUSE (MAGNETRON)
SECONDARY INTERLOCK SWITCH
PRIMARY INTERLOCK SYSTEM
MONITOR SWITCH
MONITOR FUSE
UPPER HEATER
LOWER HEATER
THERMISTOR
NOISE FILTER
TOUCH CONTROL PANEL
SWITCH UNIT
RELAY RY1
RELAY RY2
RELAY RY3
RELAY RY4
RELAY RY5
EXPRESS DEFROST
FOIL PATTURN ON P.W.B.
FAN MOTOR
TURNTABLE MOTOR
POWER SUPPLY CORD
OVEN LAMP
SHORTED WIRE HARNESS
OPENED WIRE HARNESS
MIS-ADJUSTMENT OF SWITCHES
TEST PROCEDURE
Upper and lower heater do not
operate.
Temperature is lower or higher than
preset.
Oven stops after 4 minutes 15 sec..
12
R-55TS-F
TEST PROCEDURES
PROCEDURE
LETTER
A
COMPONENT TEST
MAGNETRON ASSEMBLY TEST
1.
2.
3.
4.
5.
6.
7.
8.
9.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
To test for an open filament, isolate the magnetron from the high voltage circuit. A continuity check across
the magnetron filament leads should indicate less than 1 ohm.
To test for a shorted magnetron, connect the ohmmeter leads between the magnetron filament leads and
chassis ground. This test should indicate an infinite resistance. If there is little or no resistance the
magnetron is grounded and must be replaced.
Reconnect all leads removed from components during testing.
Reinstall the outer case (cabinet).
Reconnect the power supply cord after the outer case is installed.
Run the oven and check all functions.
MICROWAVE OUTPUT POWER
The following test procedure should be carried out with the microwave oven in a fully assembled condition
(outer case fitted).
HIGH VOLTAGES ARE PRESENT DURING THE COOK CYCLE, SO EXTREME CAUTION SHOULD
BE OBSERVED.
Power output of the magnetron can be measured by performing a water temperature rise test. This test
should only be used if above tests do not indicate a faulty magnetron and there is no defect in the following
components or wiring: silicon rectifier, high voltage capacitor and power transformer. This test will require
a 16 ounce (453cc) measuring cup and an accurate mercury thermometer or thermocouple type temperature
tester. For accurate results, the following procedure must be followed carefully:
1. Fill the measuring cup with 16 oz. (453cc) of tap water and measure the temperature of the water with
a thermometer or thermocouple temperature tester. Stir the thermometer or thermocouple through the
water until the temperature stabilizes. Record the temperature of the water.
2. Place the cup of water in the oven. Operate oven at P100(100%) selecting more than 60 seconds cook
time. Allow the water to heat for 60 seconds, measuring with a stop watch, second hand of a watch or
the digital read-out countdown.
3. Remove the cup from the oven and again measure the temperature, making sure to stir the thermometer
or thermocouple through the water until the maximum temperature is recorded.
4. Subtract the cold water temperature from the hot water temperature. The normal result should be 21.7
to 40.4˚F(12.1 to 22.4˚C) rise in temperature. If the water temperatures are accurately measured and
tested for the required time period the test results will indicate if the magnetron tube has low power output
(low rise in water temperature) which would extend cooking time or high power output (high rise in water
temperature) which would reduce cooking time. Because cooking time can be adjusted to compensate
for power output, the magnetron tube assembly should be replaced only if the water temperature rise test
indicates a power output well beyond the normal limits. The test is only accurate if the power supply line
voltage is 120 volts and the oven cavity is clean.
B
POWER TRANSFORMER TEST
1.
2.
3.
4.
5.
6.
7.
8.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
Disconnect the primary input terminals and measure the resistance of the transformer with an ohmmeter.
Check for continuity of the coils with an ohmmeter. On the R x 1 scale, the resistance of the primary coil
should be less than 1 ohm and the resistance of the high voltage coil should be approximately 114 ohms;
the resistance of the filament coil should be less than 1 ohm.
Reconnect all leads removed from components during testing.
Reinstall the outer case (cabinet).
Reconnect the power supply cord after the outer case is installed.
Run the oven and check all functions.
(HIGH VOLTAGES ARE PRESENT AT THE HIGH VOLTAGE TERMINAL, SO DO NOT ATTEMPT TO
MEASURE THE FILAMENT AND HIGH VOLTAGE.)
13
R-55TS-F
TEST PROCEDURES
PROCEDURE
LETTER
C
COMPONENT TEST
HIGH VOLTAGE RECTIFIER TEST
1.
2.
3.
4.
5.
6.
7.
8.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
Isolate the 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.
Reconnect all leads removed from components during testing.
Reinstall the outer case (cabinet).
Reconnect the power supply cord after the outer case is installed.
Run the oven and check all functions.
NOTE: Be sure to use an ohmmeter that will supply a forward bias voltage of more than 6.3 volts.
D
HIGH VOLTAGE CAPACITOR TEST
1.
2.
3.
4.
5.
6.
7.
8.
E
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
If the capacitor is open, no high voltage will be available to the magnetron. Disconnect input leads and
check for a short or open between the terminals using an ohmmeter.
Checking with a high ohm scale, if the high voltage capacitor is normal, the meter will indicate continuity
for a short time and should indicate an open circuit once the capacitor is charged. If the above is not the
case, check the capacitor with an ohmmeter to see if it is shorted between either of the terminals and case.
If it is shorted, replace the capacitor.
Reconnect all leads removed from components during testing.
Reinstall the outer case (cabinet).
Reconnect the power supply cord after the outer case is installed.
Run the oven and check all functions.
OVEN TERMOSTAT
1.
2.
3.
4.
5.
6.
7.
8.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
A continuity check across the oven thermostat terminals should indicate a closed circuit unless the
temperature of the oven thermostat reaches approximately 302˚F(150˚C). The oven thermostat resets
automatically below approximately 266˚F(130˚C).
Reconnect all leads removed from components during testing.
Reinstall the outer case (cabinet).
Reconnect the power supply cord after the outer case is installed.
Run the oven and check all functions.
THERMAL CUT-OUT TEST 125˚C
1.
2.
3.
4.
5.
6.
7.
8.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
A continuity check across the thermal cut-out terminals should indicate a closed circuit. If the temperature
of thethermal cut-out reaches approximately 257˚F(125˚C), the thermal cut-out opens. An open thermal
cut-out indicates overheating of the upper heater, exchange the thermal cut-out. Check for restricted air
flow to the upper heater, especially the cooling fan air guide.
Reconnect all leads removed from components during testing.
Reinstall the outer case (cabinet).
Reconnect the power supply cord after the outer case is installed.
Run the oven and check all functions.
TEMPERATURE FUSE (MAGNETRON) TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
14
R-55TS-F
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
3. Discharge high voltage capacitor.
4. A continuity check across the temperature fuse terminals should indicate a closed circuit unless the
temperature of the magnetron reaches approximately 302˚F(150˚C).
An open temperature fuse indicates overheating of the magnetron. Check for restricted air flow to the
magnetron, especially the cooling fan and air guide.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
CAUTION: IF THE THERMAL CUT-OUT, THERMOSTAT OR TEMPERATURE FUSE INDICATES AN
OPEN CIRCUIT AT ROOM TEMPERATURE, REPLACE THERMAL CUT-OUT, THERMOSTAT OR TEMPERATURE FUSE.
F
SECONDARY INTERLOCK SWITCH TEST
1.
2.
3.
4.
5.
6.
7.
8.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal
of the switch. The meter should indicate an open circuit with the door open and a closed circuit with the
door closed. If improper operation is indicated, replace the secondary interlock switch.
Reconnect all leads removed from components during testing.
Reinstall the outer case (cabinet).
Reconnect the power supply cord after the outer case is installed.
Run the oven and check all functions.
PRIMARY INTERLOCK SYSTEM TEST
DOOR SENSING SWITCH
1.
2.
3.
4.
5.
6.
7.
8.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal
of the switch. The meter should indicate an open circuit with the door open and a closed circuit with the
door closed. If improper operation is indicated, replace the door sensing switch.
Reconnect all leads removed from components during testing.
Reinstall the outer case (cabinet).
Reconnect the power supply cord after the outer case is installed.
Run the oven and check all functions.
NOTE: If the door sensing switch contacts fail in the open position and the door is closed, the turntable
and oven light will be activated by relay(RY1).
PRIMARY INTERLOCK RELAY (RY2)
1.
2.
3.
4.
5.
6.
7.
8.
G
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
Disconnect two (2) wire leads from the male tab terminals of the Primary Interlock Relay. Check the state
of the relay contacts using a ohmmeter. The relay contacts should be open. If the relay contacts are
closed, replace the circuit board entirely or the relay itself.
Reconnect all leads removed from components during testing.
Reinstall the outer case (cabinet).
Reconnect the power supply cord after the outer case is installed.
Run the oven and check all functions.
MONITOR SWITCH TEST
1.
2.
3.
4.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
Before performing this test, make sure that the secondary interlock switch and the primary interlock relay
15
R-55TS-F
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
5.
6.
7.
8.
H
are operating properly, according to the above Switch Test Procedure. Disconnect the wire lead from the
monitor switch (COM) terminal. Check the monitor switch operation by using the ohmmeter as follows.
When the door is open, the meter should indicate a closed circuit. When the monitor switch actuator is
pushed by a screw driver through the lower latch hole on the front plate of the oven cavity with the door
opened (in this condition the plunger of the monitor switch is pushed in), the meter should indicate an open
circuit. If improper operation is indicated, the switch may be defective. After testing the monitor switch,
reconnect the wire lead to the monitor
switch (COM) terminal and check the
RED
BLU/WHT
Screw Driver
continuity of the monitor circuit.
Reconnect all leads removed from
components during testing.
Reinstall the outer case (cabinet).
Reconnect the power supply cord after
Monitor
Switch
the outer case is installed.
Ohmmeter
Secondary
Run the oven and check all functions.
Interlock Switch
BLOWN MONITOR FUSE TEST
1.
2.
3.
4.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
If the monitor fuse is blown when the door is opened, check the primary interlock relay (RY2), relay (RY1),
secondary interlock switch and monitor switch according to the "TEST PROCEDURE" for those switches
before replacing the blown Monitor fuse.
CAUTION: BEFORE REPLACING A BLOWN MONITOR FUSE, TEST THE PRIMARY INTERLOCK
RELAY (RY2), RELAY (RY1), SECONDARY INTERLOCK SWITCH, DOOR SENSING
SWITCH AND MONITOR SWITCH FOR PROPER OPERATION.
If the monitor fuse is blown by improper switch operation, the monitor fuse and monitor switch must be
replaced with "monitor fuse and monitor switch assembly" part number FFS-BA038WRKZ, even if the monitor
switch operates normally. The monitor fuse and monitor switch assembly is comprised of a 15 ampere fuse
and switch.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
I
UPPER HEATER AND LOWER HEATER TEST
1.
2.
3.
4.
5.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
Make sure the heater is cooled completely.
Resistance of heater.
Disconnect the wire leads to the heater to be tested. Using ohmmeter with low resistance range. Check
the resistance across the terminals of the heater as described in the following table.
Parts name
Upper heater
Lower heater
Table: Resistance of heater
Resistance
Approximately 18.9 Ω
Approximately 28.2 Ω
6. Insulation resistance.
Disconnect the wire leads to the heater to be tested. Check the insulation resistance between the heater
terminal and cavity using a 500V - 100MΩ insulation tester. The insulation resistance should be more
than 10 MΩ in the cold start.
7. If the results of above test 5 and/or 6 are out of above specifications, the heater is probably faulty and
should be replaced.
8. Reconnect all leads removed from components during testing.
16
R-55TS-F
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
9. Reinstall the outer case (cabinet).
10.Reconnect the power supply cord after the outer case is installed.
11.Run the oven and check all functions.
J
THERMISTOR TEST
1.
2.
3.
4.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
Disconnect connector-C from the control unit. Measure the resistance of the thermistor with an
ohmmeter. Connect the ohmmeter leads to Pin No’s 1 and 2.
Room Temperature
68˚F(20˚C) - 86˚F(30˚C)
5.
6.
7.
8.
9.
K
Resistance
Approx. 293kΩ - 184KΩ
If the meter does not indicate above resistance, replace the thermistor
Reconnect all leads removed from components during testing.
Reinstall the outer case (cabinet).
Reconnect the power supply cord after the outer case is installed.
Run the oven and check all functions.
CHECKING TEMPERATURE IN THE PREHEAT OF BAKE MODE
The following test procedure should be carried out with the microwave oven is a fully assembled
condition (outer case fitted).
It is difficult to measure the exact temperature in the oven. An accurate thermocouple type temperature tester
must be used. A low priced bi-metal type thermometer is not reliable or accurate.
The temperature should be checked with outer case cabinet installed, approx. 5 minutes after preheat
temperature is reached (audible signal sounds four times). The temperature experienced may be approx.
30˚F more or less than indicated on the display, however, in most cases the food cooking results will be
satisfactory.
Difference in power supply voltage will also affect the oven temperature. The Household power supply
voltage may sometimes become lower than the rated voltage (120 V) and cause under-cooking. If the power
supply voltage is 10% lower than the rated voltage, longer cooking time is required by 10% to 20%.
L
NOISE FILTER TEST
1.
2.
3.
4.
5.
6.
7.
8.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
Disconnect the lead wires from the terminal the noise filter. Using an
ohmmeter, check between the terminals as described in the following
table. If incorrect reading are obtained, replace the noise filter.
Reconnect all leads removed from components during testing.
Reinstall the outer case (cabinet).
Reconnect the power supply cord after the outer case is installed.
Run the oven and check all functions.
MEASURING POINT
M
NOISE FILTER
N
L
FUSE 15A
RESISTOR 470KΩ 1/2W
LINE CROSS CAPACITOR
1.0µF / AC 250V
NOISE SUPPRESSION COIL
INDICATION OF OHMMETER
Between Hot and Neutral
Open circuit.
Between terminal N and WHITE
Short circuit.
Between terminal L and RED
Short circuit.
LINE BYPASS
CAPACITOR
0.0033µF / AC 250V
WHITE
LINE BYPASS
CAPACITOR
0.0033µF / AC 250V
RED
CONTROL UNIT TEST
The control unit 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 control unit is divided into two units, Power Unit and Switch Unit, and
troubleshooting by unit replacement is described according to the symptoms indicated.
17
R-55TS-F
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
Before testing,
1)
2)
3)
4)
5)
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
Disconnect the leads to the primary of the power transformer.
Ensure that these leads remain isolated from other components and oven chassis by using insulation
tape.
1. Switch Unit.
NOTE ;
1) Re-install the outer case (cabinet).
2) Reconnect the power supply cord after the outer case is installed.
3) Run the oven and check all functions.
The following symptoms indicate a defective switch 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.
d) When rotating the encoder (rotary dial), the cooking time can not be entered.
If the switch unit is defective, replace the switch unit together with the power unit.
2. Power Unit.
The following symptoms indicate a defective power unit. If the power unit is defective, replace the power
unit together with the switch unit.
2-1 In connection with pads.
a) When touching the pads, a certain group of pads do not produce a signal.
b) When touching the pads, no pads produce a signal.
2-2 In connection with indicators
a) At a certain digit, all or some segments do not light up.
b) At a certain digit, brightness is low.
c) Only one indicator does not light.
d) The corresponding segments of all digits do not light up; or they continue to light up.
e) Wrong figure appears.
f) A certain group of indicators do not light up.
g) The figure of all digits flicker.
2-3 Other possible problems caused by defective control unit.
a) Buzzer does not sound or continues to sound.
b) Clock does not operate properly.
c) Cooking is not possible.
d) Proper temperature measurement is not obtained.
When testing is completed,
1) Disconnect the power supply cord, and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Reconnect all leads removed from components during testing.
5) Re-install the outer case (cabinet).
6) Reconnect the power supply cord after the outer case is installed.
7) Run the oven and check all functions.
N
SWITCH UNIT TEST
1.
2.
3.
4.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
Using an ohmmeter and referring to the switch unit matrix indicated on the control unit circuit, check the
circuit between the pins of the switch unit that correspond to the STOP/CLEAR pad. When the pad is
pressed, the ohmmeter should indicate short circuit. When the pad is released, the ohmmeter should
indicate open circuit. If incorrect readings are obtained, the key unit is faulty and must be replaced. About
the other pads, the above method may be used.
5. Reconnect all leads removed from components during testing.
6. Re-install the outer case (cabinet).
18
R-55TS-F
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
13P HARNESS WH-B
R50
1
R51
4.7K
R52
100K
R53
2
4
5
6
START/
MINUTEPLUS
SW1
BAKE
Switch Unit
7
STOP/
CLEAR
SW2
TIMER/
CLOCK
SW6
REHEAT
SW5
100K
SW1
A B C ENCODER
O
3
4.7K
8
FRESH
EXPRESS
DEFROST VEGETABLES
SW3
SW4
POPFROZEN
CORN
ENTREE
SW7
SW8
SW9
MICRO
SW10
GRILL
SW11
TOAST
SW13
SNACKS
SW14
BAKE
SW15
BEVERAGE
SW12
9
10
11
12
RELAY TEST
1.
2.
3.
4.
5.
6.
7.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
Disconnect the leads to the primary of the power transformer.
Ensure that these leads remain isolated from other components and oven chassis by using insulation tape.
After that procedure, re-connect the power supply cord.
Remove the outer case and check voltage between Pin Nos. 1 and 3 of the 7 pin connector (A) on the
control unit with an A.C. voltmeter.
The meter should indicate 120 volts, if not check oven circuit.
Shut off, Cook and Heater 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, grill cooking
operation, or bake cooking operation.
DC. voltage indicated ............. Defective relay.
DC. voltage not indicated ........ Check diode which is connected to the relay coil. If diode is good, control
unit is defective.
RELAY SYMBOL
OPERATIONAL VOLTAGE
RY1
RY2
RY3
RY4
RY5
Approx. 24.2V D.C.
Approx. 23.4V D.C.
Approx. 23.4V D.C.
Approx. 23.4V D.C.
Approx. 24.2V D.C.
CONNECTED COMPONENTS
Oven lamp/ Turntable motor
Power transformer
Upper heater
Lower heater
Fan motor
8. Disconnect the power supply cord, and then remove outer case.
9. Open the door and block it open.
10.Discharge high voltage capacitor.
11.Reconnect all leads removed from components during testing.
12.Re-install the outer case (cabinet).
13.Reconnect the power supply cord after the outer case is installed.
14.Run the oven and check all functions.
P
EXPRESS DEFROST TEST
WARNING : The oven should be fully assembled before following procedure.
(1) Place one cup of water in the center of the turntable tray in the oven cavity.
(2) Close the door, touch the “ Express Defrost “ pad once and touch the "START" pad.
(3) The oven is in Express Defrost cooking condition.
(4) The oven will operate as follows
WEIGHT
0.5lb
1ST STAGE
LEVEL
TIME
70%
1min. 2sec.
2ND STAGE
LEVEL
TIME
0%
1min. 2sec.
3RD STAGE
LEVEL
TIME
50%
32sec.
4TH STAGE
LEVEL
TIME
30%
50sec.
(5) If improper operation is indicated, the control unit is probably defective and should be checked.
19
R-55TS-F
TEST PROCEDURES
COMPONENT TEST
FOIL PATTERN ON THE PRINTED WIRING BOARD TEST
To protect the electronic circuits, this model is provided with a fine foil pattern added to the primary on the
PWB, this foil pattern acts as a fuse.
1. Foil pattern check and repairs.
1) Disconnect the power supply cord, and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Follow the troubleshooting guide given below for repair.
STEPS
OCCURRENCE
CAUSE OR CORRECTION
1
Only pattern at “a” is broken.
*Insert jumper wire J1 and solder.
2
Pattern at “a” and “b” are broken.
*Insert the coil RCILF2003YAZZ between “c” and “d”.
d
VRS1
b
a
J1
E
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 212Ω ± 10%). If any
abnormal condition is detected, replace
the control unit.
RY6
PROCEDURE
LETTER
Q
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 high voltage capacitor.
4) Disconnect the leads to the primary of the power transformer.
5) Ensure that these leads remain isolated from other components and oven chassis by using
insulation tape.
6) After that procedure, re-connect the power supply cord.
7) Follow the troubleshooting guide given below for repair.
STEPS
1
2
8)
9)
10)
11)
12)
13)
14)
OCCURRENCE
CAUSE OR CORRECTION
The rated AC voltage is not present between
Pin Nos. 1 and 3 of the 7-pin connector (A).
The rated AC voltage is present at primary
side of low voltage transformer.
Check supply voltage and oven power cord.
Low voltage transformer or secondary circuit defective.
Check and replace control unit.
Disconnect the power supply cord, and then remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
Reconnect all leads removed from components during testing.
Re-install the outer case (cabinet).
Reconnect the power supply cord after the outer case is installed.
Run the oven and check all functions.
20
R-55TS-F
TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOUCH CONTROL PANEL
3) Synchronizing Signal Circuit
The power source synchronizing signal is available in
order to compose a basic standard time in the clock
circuit. It accompanies a very small error because it
works on commercial frequency.
The touch control section consists of the following units as
shown in the touch control panel circuit.
(1) Switch Unit
(2) Power Unit
4) Reset Circuit
A circuit to generate a signal which resets the LSI to the
initial state when power is supplied.
The principal functions of these units and signals
communicated among them are explained below.
Switch Unit
The switch unit is composed of a matrix, signals generated
in the LSI are sent to the switch unit from P14 - P17.
When a key pad is touched, a signal is completed through
the switch unit and passed back to the LSI through P24 P27 to perform the function that was requested.
5) Buzzer Circuit
The buzzer is responsive to signals from the LSI to emit
audible sounds (key touch sound and completion sound).
6) Door Sensing Switch
A switch to “tell” the LSI if the door is open or closed.
Encoder
The encoder convents the signal generated by LSI into the
plus signal, and the plus signal is returned to the LSI.
7) Relay Circuit
To drive the magnetron, upper heater, lower heater, fan
motor, turntable motor and light the oven lamp.
Power Unit
Power unit consists of LSI, power source circuit,
synchronizing signal circuit, ACL circuit, buzzer circuit,
relay circuit, temperature measurement circuit and indicator
circuit.
8) Indicator Circuit
This circuit consists of 4-digits, 13-segments and 3common electrodes using a Liquid Crystal Display.
9) Temperature Measurement Circuit: (OVEN
THERMISTOR)
The temperature in the oven cavity is sensed by the
thermistor. The variation of resistance according to
sensed temperature is detected by the temperature
measurement circuit and the result applied to LSI. The
LSI uses this information to control the relay and display
units.
1) LSI
This LSI controls the temperature measurement signal,
key strobe signal, relay driving signal for oven function
and indicator signal.
2) Power Source Circuit
This circuit generates voltage necessary in the control
unit.
Symbol
VC
Voltage
-5.2V
Application
LSI(IC1)
21
R-55TS-F
DESCRIPTION OF LSI
LSI
The I/O signal of the LSI is detailed in the following table.
Pin No.
Signal
I/O
Description
1-2
VL2-VL1
IN
Power source voltage input terminal.
Standard voltage for LCD.
3-5
AN7-AN5
IN
Terminal to change functions according to the model.
DC voltage in accordance with the model in operation is applied to set up its function.
6
AN4
OUT
Terminal not used.
7
AN3
IN
Terminal not used.
8
AN2
IN
Input signal which communicates the door open/close information to LSI.
Door closed; “H” level signal.
Door opened; “L” level signal.
9
P61
OUT
Terminal not used.
10
P60
IN
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.
11
P57
IN
Terminal not used.
12
P56
OUT
Oven lamp and turntable motor driving signal(Square Waveform : 60Hz).
16.7 msec.
To turn on and off shut-off relay (RY1). The
square waveform voltage is delivered to the relay
(RY1) driving circuit.
H
L
During cooking
13
P55
OUT
Terminal not used.
14
P54
OUT
Signal to sound buzzer.
A: key touch sound.
0.1 sec.
A
B: Completion sound.
C: When the temperature of the oven cavity
reaches the preset temperature in the
preheating mode, or when the preheating
hold time (30 minutes) is elapsed.
2.0 sec.
B
1.0 sec.
1.0 sec.
H : GND
B
L
15
P53
OUT
Magnetron high-voltage circuit driving signal.
To turn on and off the relay RY2. In 100%
POWER operation, the signals hold “L” level
during microwave cooking and “H” level while not
cooking. In other cooking modes (70%, 50%,
30%, 10%) the signal turns to “H” level and “L”
level in repetition according to the power level.
16
P52
OUT
Fan motor driving signal.
To turn on and off the fan motor relay RY5. “L”
level during cooking, or after grill cooking or bake
cooking. “H” level otherwise.
ON/OFF time ratio in micro cooking
(a 32 second time base)
MICRO
COOK
ON
OFF
100 %
32 sec.
0 sec.
70 %
24 sec.
8 sec.
50 %
18 sec.
14 sec.
30 %
12 sec.
20 sec.
10 %
6 sec.
26 sec.
OFF
H : GND
L
ON
During cooking, after grill
cooking or bake cooking
17
P51
OUT
Upper heater driving signal.
To turn on and off the upper heater relay (RY3).
“L” level during GRILL1, GRILL2 cooking or Bake
cooking. “H” level otherwise.
OFF
ON
H : GND
L
(During Grill1, Grill2 or Bake cooking)
22
R-55TS-F
Pin No.
Signal
I/O
Description
18
P50
OUT
Lower heater driving signal.
To turn on and off the lower heater relay (RY4).
“L” level during GRILL2 cooking or Bake cooking.
“H” level otherwise.
OFF
H : GND
L
ON
(During Grill2 or Bake cooking)
19-20
P47-P46
OUT
Terminal not used.
21
P45
OUT
Terminal not used.
22
P44
OUT
Terminal not used.
23
INT1
IN
Signal coming from encoder.
When the encoder is turned, the contacts of encoder make plus signals. And plus signals are
input into INT1.
24
INT0
IN
Signal to synchronized LSI with commercial power source frequency(60Hz).
This is basic timing for time processing of LSI.
H: GND
L(-5V)
16.7 msec.
25
P41
IN
Signal coming from encoder.
Signal similar to INT1.Plus signals are input into P41.
26
P40
IN
Connected to VC.
27
RESET
IN
Auto clear terminal.
Signal is input to reset the LSI to the initial state when power is applied. Temporarily set to
“L” level the moment power is applied, at this time the LSI is reset. Thereafter set at “H” level.
28
P71
OUT
Timing signal output terminal for temperature measurement(OVEN THERMISTOR).
“H” level (GND) : Thermistor OPEN timing.
“L” level (-5V) : Temperature measuring timing. (Bake cooking)
29
P70
OUT
Terminal not used.
30
XIN
IN
31
XOUT
OUT
32
VSS
IN
Power source voltage: -5V.
VC voltage of power source circuit input.
33
P27
IN
Signal coming from touch tact switch.
When any one of tact switches SW1, SW5, SW9, SW13 on switch unit matrix is touched, a
corresponding signal from P14-P17 will be input into P27. When no tact switch is touched,
the signal is held at “H” level.
34
P26
IN
Signal similar to P27.
When any one of tact switches SW2, SW6, SW10, SW14 on switch unit matrix is touched,
a corresponding signal will be input into P26.
35
P25
IN
Signal similar to P27.
When any one of tact switches SW3, SW7, SW11, SW15 on switch unit matrix is touched,
a corresponding signal will be input into P25.
36
P24
IN
Signal similar to P27.
When any one of tact switches SW4, SW8, SW12 on switch unit matrix is touched, a
corresponding signal will be input into P24.
37-40
P23-P20
OUT
Terminal not used.
41
P17
OUT
Tact switch strobe signal.
Signal applied to tact switch section. A pulse signal is input to P24 - P27 terminal while one
of tact swithes (SW1, SW2. SW3, SW4) on matrix is touched.
42
P16
OUT
Tact switch strobe signal.
Signal applied to tact switch section. A pulse signal is input to P24 - P27 terminal while one
of tact swithes (SW5, SW6. SW7, SW8) on matrix is touched.
Internal clock oscillation frequency input setting.
The internal clock frequency is set by inserting the ceramic filter oscillation circuit with respect
to XOUT terminal.
Internal clock oscillation frequency control output.
Output to control oscillation input of XIN.
23
R-55TS-F
Pin No.
Signal
I/O
Description
43
P15
OUT
Tact switch strobe signal.
Signal applied to tact switch section. A pulse signal is input to P24 - P27 terminal while one
of tact swithes (SW9, SW10. SW11, SW12) on matrix is touched.
44
P14
OUT
Tact switch strobe signal.
Signal applied to tact switch section. A pulse signal is input to P24 - P27 terminal while one
of tact swithes (SW13, SW14. SW15) on matrix is touched.
45-48
P13-P10
IN
Terminal not used.
49-56
P07-P00
OUT
Terminal not used.
57-59
P37-P35
IN
Terminal not used.
60-72
SEG12-SEG0
OUT
Segment data signal.
Connected to LCD.
The relation between signals are as follows:
LSI signal (Pin No.) LCD (Pin No.) LSI signal (Pin No.) LCD (Pin No.)
SEG 0 (72) ......................... SEG0
SEG7 (65) ....................... SEG7
SEG 1 (71) ......................... SEG1
SEG8 (64) ....................... SEG8
SEG 2 (70) ......................... SEG2
SEG9 (63) ....................... SEG9
SEG 3 (69) ......................... SEG3
SEG10 (62) ................... SEG10
SEG 4 (68) ......................... SEG4
SEG11 (61) ................... SEG11
SEG 5 (67) ......................... SEG5
SEG12 (60) ................... SEG12
SEG 6 (66) ......................... SEG6
73
VCC
IN
Connected to GND.
74
VREF
IN
Connected to GND.
75
AVSS
IN
Connected to VC.
76
COM3
OUT
Terminal not used.
77
COM2
OUT
Common data signal.
Connected to LCD (COM2).
78
COM1
OUT
Common data signal.
Connected to LCD (COM1).
79
COM0
OUT
Common data signal.
Connected to LCD (COM0).
80
VL3
IN
Power source voltage input terminal.
Standard voltage for LCD.
24
R-55TS-F
TOUCH CONTROL PANEL SERVICING
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).
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. 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.
3. Servicing Tools
Tools required to service the touch control panel assembly.
1) Soldering iron: 60W
(It is recommended to use a soldering iron with a grounding
terminal.)
2) Oscilloscope: Single beam, frequency range: DC-10MHz
type or more advanced model.
3) Others: Hand tools
4. Other Precautions
1) Before turning on the power source of the control unit,
remove the aluminium foil applied for preventing static
electricity.
2) Connect the 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.
25
R-55TS-F
PRECAUTIONS FOR USING LEAD-FREE SOLDER
1. Employing lead-free solder
The "Main PWB" of this model employs lead-free solder. This is indicated by the "LF" symbol printed on the PWB and
in the service manual. The suffix letter indicates the alloy type of the solder.
Example:
Sn-Ag-Cu
Indicates lead-free solder of tin, silver and copper.
2. Using lead-free wire solder
When repairing a PWB with the "LF" symbol, only lead-free solder should be used. (Using normal tin/lead alloy solder
may result in cold soldered joints and damage to printed patterns.)
As the melting point of lead-free solder is approximately 40˚C higher than tin/lead alloy solder, it is recommend that a
dedicated bit is used, and that the iron temperature is adjusted accordingly.
3. Soldering
As the melting point of lead-free solder (Sn-Ag-Cu) is higher and has poorer wettability, (flow), to prevent damage to
the land of the PWB, extreme care should be taken not to leave the bit in contact with the PWB for an extended period
of time. Remove the bit as soon as a good flow is achieved. The high content of tin in lead free solder will cause premature
corrosion of the bit. To reduce wear on the bit, reduce the temperature or turn off the iron when it is not required.
Leaving different types of solder on the bit will cause contamination of the different alloys, which will alter their
characteristics, making good soldering more difficult. It will be necessary to clean and replace bits more often when using
lead-free solder. To reduce bit wear, care should be taken to clean the bit thoroughly after each use.
26
R-55TS-F
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
WARNING AGAINST HIGH VOLTAGE:
Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts may
result in severe, possibly fatal, electric shock.
(Example)
High Voltage Capacitor, Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..
WARNING:
Avoid possible exposure to microwave energy. Please follow the instructions below before
operating the oven.
1. Disconnect the power supply cord.
2. 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 push the door open
button 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.).
1.
2.
3.
4.
5.
6.
Door does not close firmly.
Door hinge, support or latch hook is damaged.
The door gasket or seal is damaged.
The door is bent or warped.
There are defective parts in the door interlock system.
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.
Carry out any remedial work that is necessary before
operating the oven.
Do not operate the oven if any of the following conditions
exist;
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 block it open.
3) Discharge the high voltage capacitor and wait for 60
seconds.
2. Don’t let the wire leads touch to the following parts;
1) High voltage parts:
Magnetron, Power transformer, High voltage capacitor
and High voltage rectifier assembly.
2) Hot parts:
Upper heater, Lower heater, Oven lamp, Magnetron,
Power transformer and Oven cavity.
3) Sharp edge:
Bottom plate, Oven cavity, Waveguide flange and
other metallic plate.
4) Movable parts (to prevent a fault)
Fan blade, Fan motor, Turntable motor, Switch,
Switch lever, Open button.
3. Do not catch the wire leads in the outer case cabinet.
4. Insert the positive lock connector until its pin is locked
and make sure that the wire leads do not come off even
if the wire leads are pulled.
5. To prevent an error function, connect the wire leads
correctly, referring to the Pictorial Diagram.
Please refer to ‘OVEN PARTS, CABINET PARTS, CONTROL PANEL PARTS, DOOR PARTS’, when carrying out any of
the following removal procedures:
OUTER CASE REMOVAL
To remove the outer case, proceed as follows.
1. Disconnect the power supply cord.
2. Open the door and block it open.
3. Remove the six (6) screws holding the rear cover to the
rear reflector and the outer case cabinet.
4. Remove the two (2) screws holding the outer case
cabinet to the bottom plate assembly, using a T20H Torx
type of GTXH20-100 screw driver.
5. Remove the remaining two (2) screws holding the outer
case cabinet to the bottom plate assembly.
6. Slid the entire outer case back out about 1 inch (3cm) to
free it from retaining clips on the cavity face plate.
7. Lift entire outer case from the unit.
27
R-55TS-F
CAUTION: 1. DISCONNECT OVEN FROM POWER SUP
PLY BEFORE REMOVING OUTER CASE.
2. DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN
COMPONENTS OR WIRING.
NOTE: When replacing the outer case, the 2 special
Torx screws must be reinstalled in the same
locations.
Special screw
Screw Driver
(Type: TORX T20 H or
GTXH20-100)
POWER TRANSFORMER REMOVAL
Reinstallation
1. Rest transformer on the bottom plate with its primary
terminals toward the oven face plate.
2. Secure transformer with four (4) screws (from bottom side)
to bottom plate.
3. Reconnect wire leads (primary) to power transformer
and filament leads and high voltage wire of transformer
to magnetron and high voltage capacitor. Refer to
"PICTORIAL DIAGRAM".
4. Reinstall the capacitor band with the high voltage
capacitor to the bottom plate assembly with two (2)
screws.
5. Reinstall outer case and check that oven is operating
properly.
1. Disconnect the power supply cord and then remove
outer case.
2. Open the oven door and block it open.
3. Discharge high voltage capacitor.
4. Remove two (2) screws holding the capacitor band with
the high voltage capacitor to the bottom plate assembly.
5. Disconnect wire leads (primary) from power transformer
and the filament leads and high voltage wire from the
magnetron and capacitor terminals.
6. Remove four (4) screws holding transformer to bottom
plate (from bottom side ).
7. Remove transformer from bottom plate.
HIGH VOLTAGE RECTIFIER AND HIGH VOLTAGE CAPACITOR REMOVAL
1. Disconnect the power supply cord and then remove
outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the high voltage wire of the power transformer
from the high voltage capacitor.
5. Disconnect the high voltage wire of high voltage rectifier
assembly from the magnetron.
6. Disconnect the filament lead (short one) of the power
transformer from the high voltage capacitor.
7. Remove the two (2) screws holding capacitor holder to
bottom plate.
8. Remove one (1) screw holding high voltage rectifier
assembly to capacitor holder.
9. Disconnect rectifier terminal from capacitor.
High voltage rectifier assembly is now free.
10.Remove capacitor holder. Capacitor is now free.
CAUTION: WHEN REPLACING HIGH VOLTAGE RECTIFIER AND HIGH VOLTAGE CAPACITOR,
GROUND SIDE TERMINAL OF THE HIGH
VOLTAGE RECTIFIER MUST BE SECURED
FIRMLY WITH A GROUNDING SCREW.
MAGNETRON REMOVAL
Removal
1. Disconnect the power supply cord and then remove the
outer case.
2. Open the oven door and block it open.
3. Discharge the high voltage capacitor.
4. Disconnect all wire leads from the magnetron and the
oven lamp.
5. Remove the two (2) screws holding the chassis support
to the oven cavity front flange and the bottom plate
assembly. And remove the chassis support.
6. Release the snap band of the main wire harness from
the air duct.
7. Remove the one (1) screw holding the temperature fuse
(magnetron) to the air duct.
8. Remove the one (1) screw holding the thermistor angle
to the magnetron.
9. Carefully remove the three (3) screws holding the
magnetron to the waveguide flange.
10.Remove the magnetron with care so that its antenna is
not hit by any metal object.
11.Remove the two (2) screws holding the air duct to the
magnetron and remove it.
12.Remove the two (2) screws holding the reflector to the
magnetron and remove it.
13.Now, the magnetron is free.
Reinstallation
1. Reinstall the reflector to the magnetron with the two (2)
screws.
28
R-55TS-F
2. Reinstall the air duct to the magnetron with the two (2)
screws.
3. Reinstall the magnetron to the waveguide flange with
the three (3) screws.
4. Reinstall the thermistor angle to the magnetron with the
one (1) screw.
5. Reinstall the temperature fuse (magnetron) to the air
duct with the one (1) screw.
6. Reinstall the snap band of the main wire harness to the
air duct.
7. Reinstall the chassis support to the oven cavity front
flange and the bottom plate assembly with the two (2)
screws.
8. Reconnect the wire leads to the magnetron, oven lamp,
referring to "PICTORIAL DIAGRAM".
9. Reinstall the outer case and check the oven is operating
properly.
CAUTION: WHEN REPLACING MAGNETRON, BE SURE
THE R.F. GASKET IS IN PLACE AND MOUNTING SCREWS ARE TIGHTENED SECURELY.
OVEN LAMP REMOVAL
1. Disconnect the power supply cord and then remove the
outer case.
2. Open the oven door and block it open.
3. Discharge the high voltage capacitor.
4. Remove the magnetron with the air duct and the reflector
from the waveguide flange, referring to the items 4 -10
of "Removal of MAGNETRON REPLACEMENT"
5. Remove the one (1) screw holding the oven lamp to the
air duct.
6. Now, the oven lamp is free.
POSITIVE LOCK® CONNECTOR (NO-CASE TYPE) REMOVAL
Terminal
1. Disconnect the power supply cord, and then remove
outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Push the lever of positive lock® connector.
5. Pull down on the positive lock® connector.
Positive lock®
connector
1
Push
Lever
CAUTION: WHEN CONNECTING THE POSITIVE LOCK®
CONNECTORS TO THE TERMINALS, CONNECT THE POSITIVE LOCK® SO THAT THE
LEVER FACES YOU
2
Pull down
Figure C-1. Positive lock® connector
CONTROL PANEL ASSEMBLY REMOVAL
1. Disconnect the power supply cord and then remove
outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the wire leads and connectors from control unit.
5. Remove the one (1) screw holding the control panel
assembly to the oven cavity front flange.
6. Slide the control panel assembly upward and remove it.
7. Now, individual components can be removed.
CONTROL UNIT ASSEMBLY REMOVAL
1. Disconnect the power supply cord and then remove the
outer case.
2. Open the oven door and block it open.
3. Discharge the high voltage capacitor.
4. Remove the control panel assembly, referring to chapter
of "CONTROL PANEL ASSEMBLY REMOVAL".
5. Disconnect the connector CN-D of the switch unit from
the control unit.
6. Remove the four (4) screws holding the control unit to
the control panel frame, and remove the control unit.
7. Remove the eight (8) screws holding the switch unit to
the control panel frame, and remove the switch unit.
8. Pulling the timer knob and the switch unit at the same
time, carefully remove the switch unit from the control
panel frame so that the switch unit is not broken.
9. Now, the control unit assembly is free.
NOTE: When the switch unit is reinstalled, with fitting
the "D" cut position of the rotaly encoder shaft
and timer knob.
UPPER HEATER REMOVAL
2. Open the oven door and block it open.
3. Discharge the high voltage capacitor.
1. Disconnect the power supply cord and then remove the
outer case.
29
R-55TS-F
4. Remove the two (2) screws holding the main wire harness
to the upper heater.
5. Remove the one (1) screw holding the heater fix angle
left to the oven cavity top plate.
6. Carefully remove the upper heater from the oven cavity
top plate so that the right of the upper heater catch any
metal object.
7. Now, the upper heater is free.
LOWER HEATER REMOVAL
1. Disconnect the power supply cord and then remove the
outer case.
2. Open the oven door and block it open.
3. Discharge the high voltage capacitor.
4. Now, the rear cover should be removed.
5. Remove the turntable and the turntable support from the
oven cavity.
6. Remove the door assembly, referring to "Removal of
DOOR REPLACEMENT".
7. Remove the control panel assembly, referring to
"CONTROL PANEL ASSEMBLY REMOVAL".
8. Remove the two (2) screws holding the rear reflector to
the bottom plate assembly, and remove it.
9. Remove the two (2) screws holding the exhaust cover to
the bottom plate assembly, and remove it.
10.Remove the two (2) screws holding the chassis support
to the oven cavity front flange and the fan duct, and
remove the chassis support.
11.Disconnect the wire leads from the following parts;
Upper heater, Lower heater, Thermal cut out, Oven
thermostat, Fan motor, C/T fuse, Door sensing switch,
Monitor switch, Secondary interlock switch, Select relay,
Oven lamp, Magnetron
12.Release the snap band of the main wire harness from the
air duct.
13.Remove the power transformer, referring to "POWER
TRANSFORMER REMOVAL".
14.Remove the three (3) screws holding the bottom plate
assembly (rear side) to the oven cavity assembly.
15.Turn the oven over.
16.Remove the three (3) screws holding the door insertion
barrier to the oven cavity.
17.Remove the bottom plate assembly with the main wire
harness from the oven cavity assembly.
18.Remove the three (3) screws holding the bottom reflector
to the oven cavity.
19.Straighten the two (2) tabs of the bottom reflector and
remove the bottom reflector from the oven cavity.
20.Lift up the stopper and remove the lower heater.
21.Now, lower heater is free.
NOTE 1. When the lower heater is reinstalled, insert
the ceramic portion of the lower heater into
the tab plate. Or cooking result will be bad.
2. When the lower heater is reinstalled, reinstall
the lower heater so that the terminal of the
lower heater faces toward the hole of the
bottom reflector.
Stopper
Ceramic
portion
Bottom
refrector
Lower heater
Tab plate
Terminal
Lower heater
Stopper
Hole
Tab plate
Bottom
refrector
Terminal
Figure C-2. Lower heater
TURNTABLE MOTOR REMOVAL
1. Disconnect the power supply cord.
2. Remove turntable and turntable support from oven cavity.
3. Lay the oven on it's backside. Remove the turntable
motor cover by snipping off the material in eight (8)
portions.
4. Where the corners have been snipped off bend corner
areas flat. No sharp edges must be evident after removal
of the turntable motor cover.
5. Disconnect wire leads from turntable motor.
6. Straighten the two (2) tabs holding turntable motor to
turntable motor mounting angle.
7. Remove one (1) screw holding turntable motor to oven
cavity.
8. Now the turntable motor is free.
9. After replacement use the one (1) screw to fit the
turntable motor cover.
COOLING FAN MOTOR REMOVAL
REMOVAL
1. Disconnect the power supply cord and then remove
outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the wire leads from the fan motor.
5. Remove the two (2) screws holding the fan motor to the
bottom plate assembly.
30
R-55TS-F
6. Remove the fan blade from the fan motor shaft according
to the following procedure.
7. Hold the edge of the rotor of the fan motor by using a pair
of groove joint pliers.
CAUTION:
* Make sure that no metal pieces enter the gap between
the rotor and the stator of the fan motor because the
rotor is easily shaven by pliers and metal pieces
may be produced.
* Do not touch the pliers to the coil of the fan motor
because the coil may be cut or injured.
* Do not disfigure the bracket by touching with the
pliers.
8. Remove the fan blade from the shaft of the fan motor by
pulling the fan blade with your hand.
9. Now, the fan blade will be free.
CAUTION:
* Do not reuse the removed fan blade because the
hole (for shaft) may be larger than normal.
10.Now, the fan motor is free.
INSTALLATION
1. Install the fan blade to the fan motor shaft according to
the following procedure.
2. Hold the center of the bracket which supports the shaft of
the fan motor on the flat table.
3. Apply the screw lock tight into the hole (for shaft) of the
fan blade.
4. Install the fan blade to the shaft of fan motor by pushing
the fan blade with a small, light weight, ball peen hammer
or rubber mallet.
5. Install the fan motor to the oven cavity back plate with the
two (2) screws.
CAUTION:
* Do not hit the fan blade strongly when installed
because the bracket may be disfigured.
* Make sure that the fan blade rotates smooth after
installation.
* Make sure that the axis of the shaft is not slanted.
6. Connect the wire leads to the fan motor, referring to the
pictorial diagram.
Shaft
Coil
Groove joint pliers
Table
Stator
Gap
Bracket
Shaft
Axis
Rotor
Rear View
Center of
bracket
These are the positions
that should be pinched
with pliers.
Stator
Rotor
Side View
DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH REMOVAL
Reinstallation
1. Reinstall each switch in its place. The secondary interlock/
monitor switches are in the lower position and the door
sensing switch is in the upper position.
2. Secure latch hook (with two (2) mounting screws) to oven
flange.
3. Reinstall the switch lever to the oven cavity front flange.
4. Reconnect wire leads to each switch.
Refer to pictorial diagram.
5. Reinstall the control panel assembly to the oven cavity
front with the one (1) screw.
6. Reinstall the magnetron with air duct and the reflector to
the waveguide flange, referring to "Reinstallation of
MAGNETRON REPLACEMENT".
7. Make sure that the monitor switch is operating properly
and check continuity of the monitor circuit. Refer to
chapter "Test Procedure" and Adjustment procedure.
1.
2.
3.
4.
Disconnect the power supply cord and remove outer case.
Open the door and block it open.
Discharge high voltage capacitor.
Remove the magnetron with air duct and the reflector
from the waveguide flange, referring to the items 4 - 10
of "Removal of MAGNETRON REPLACEMENT".
5. Remove the control panel assembly from the oven
cavity front flange. Refer to the "CONTROL PANEL
ASSEMBLY REMOVAL".
6. Disconnect wire leads from the switches.
7. Slide the switch lever rightward and remove it from the
oven cavity front flange.
8. Remove two (2) screws holding latch hook to oven flange.
9. Remove latch hook assembly from oven flange.
10.Push outward on the two (2) retaining tabs holding
switch in place.
11.Switch is now free.
At this time switch lever will be free, do not lose it.
DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH ADJUSTMENT
3. Discharge high voltage capacitor.
If the door sensing switch, secondary interlock switch and
monitor switch do not operate properly due to a
1. Disconnect the power supply cord, and then remove
outer case.
2. Open the door and block it open.
31
R-55TS-F
should be less than 0.5mm.
2. The door sensing switch and secondary interlock switch
interrupt the circuit before the door can be open.
3. Monitor switch contacts close when door is opened.
4. Reinstall outer case and check for microwave leakage
around door with an approved microwave survey meter.
(Refer to Microwave Measurement Procedure.)
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 switch are activated with
the door closed. The horizontal position of the latch hook
should be adjusted so that the plunger of the monitor
switch is pressed with the door closed.
6. Secure the screws with washers firmly.
7. Check the operation of all switches. If each switch has
not activated with the door closed, loosen screw and
adjust the latch hook position.
Door
Latch
Heads
After adjustment, check the following.
1. In and out play of door remains less than 0.5mm when in
the latched position. First check upper position of latch
hook, pushing and pulling upper portion of door toward
the oven face. Then check lower portion of the latch
hook, pushing and pulling lower portion of the door
toward the oven face. Both results (play in the door)
Latch Hook
Door Sensing
Switch
Monitor Switch
Switch Lever
Secondary
Interlock Switch
Figure C-3. Latch Switch Adjustments
DOOR REPLACEMENT
REMOVAL
1. Disconnect the power supply cord.
2. Open the door slightly.
3. Insert a putty knife (thickness of about 0.5mm) into the
gap between the choke cover and door stopper as
shown in Figure C-4 to free engaging parts.
4. Pry the choke cover by inserting a putty knife as shown
Figure C-4.
5. Release choke cover from door panel.
6. Now choke cover is free.
NOTE: When carrying out any repair to the door, do not
bend or warp the slit choke (tabs on the door
panel assembly) to prevent microwave leakage.
7. Release two (2) pins of door panel from two (2) holes of
upper and lower oven hinges by lifting up.
8. Now, door panel with door frame is free from oven cavity.
door frame.
10.Release door panel from eight (8) tabs of door frame.
11.Now, door panel with sealer film is free.
12.Tear sealer film from door panel.
13.Now, door panel is free.
14.Slide latch head upward and remove it from door frame
with releasing latch spring from door frame and latch
head.
15.Now, latch head and latch spring are free.
16.Remove the door glass stopper from door frame.
17.Slide the front door glass rightward, then slide upward.
18.Remove the front door glass from the door frame.
19.Now, front door glass is free.
20.Straight the twelve (12) tabs of the sus cover and remove
the sus cover from the door frame.
REINSTALLATION
1. Reinstall sus cover to the door frame .
2. By bending the twelve (12) tabs of the sus cover, hold the
sus cover to the door frame.
3. Reinstall the front door glass to the door frame.
3-1. Insert the upper edge of the front door glass into the two
(2) tabs of the door frame.
3-2. Slide the front door glass downwards and insert the
lower edge of the front door glass into the four (4) tabs
of the door frame.
3-3. Slide the front door glass leftward and insert the left
edge of the front door glass into the three (3) long tabs
of the door frame.
4. Reinstall the door glass stopper so that the glass stopper
catch the upper and right corner of the front door glass.
5. Reinstall the latch spring to the latch head. Reinstall the
latch spring to the door frame. Reinstall the latch head to
Door Stopper
Choke Cover
Putty Knife
Door Frame
Figure C-4. Door Disassembly
9. Remove the two (2) screws holding the door panel to the
32
R-55TS-F
the door frame.
6. Reinstall the door panel to the door frame by fitting eight
(8) tabs of the door frame.
7. Put the sealer film on the door panel. Refer to “Sealer
Film” about how to handle new one.
8. Catch the two (2) pins of door panel on two (2) hole of the
upper and lower oven hinges.
9. Reinstall the choke cover to the door panel by pushing.
10.Reinstall the door stopper.
Note: After any service to the door;
(A) Make sure that door sensing switch and secondary
interlock switch are operating properly. (Refer to
chapter “Test Procedures”.).
(B) An approved microwave survey meter should be
used to assure compliance with proper microwave
radiation emission limitation standards.
After any service, make sure of the following :
1. Door latch heads smoothly catch latch hook through
latch holes and that latch head goes through center of
latch hole.
2. Deviation of door alignment from horizontal line of cavity
face plate is to be less than 1.0mm.
3. Door is positioned with its face pressed toward cavity
face plate.
4. Check for microwave leakage around door with an
approved microwave survey meter. (Refer to Microwave
Measurement Procedure.)
Note: The door on a microwave oven is designed to act as
an electronic seal preventing the leakage of
microwave energy from oven cavity during cook
cycle. This function does not require that 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.
Pin Upper
Oven
Hinge
Upper Oven
Hinge
Slit choke of
door panel
Lower
Oven Hinge
Door
Stopper
Lower Oven
Hinge
Pin
Choke Cover
Figure C-5. Door Replacement
SEALER FILM
Installation
1. Put the adhesive tape on the backing film of the sealer
film as shown in Fig. C-6.
2. Tear the backing film by pulling the adhesive tape.
3. Put the pasted side of the sealer film on the door panel
Sealer film
Backing film
Adhesive tape
Figure C-6. Sealer film
33
2
RED
12
1
3
34
H
RY4
1
4
5
RY3
T1
RY1
C2
5
1 RED
2
3 BRN
4
5 WHT
CN-A
1 GRN
3 BLK
2
CN-B
1 BLK
2 BLK
CN-C
BRN
BLK
BRN
RED
BLK
RED
RED
GRN
N.C.
COM.
BLU
WHT
WHT
BLU
WHT
WHT
MONITOR
SWITCH
COM.
RED
BLK
GRN
GRN
SECONDARY NO
INTERLOCK
SWITCH
COM.
N.O.
DOOR
SENSING
SWITCH
WHT
WHT
RED
RED
TURNTABLE MOTOR
LOWER HEATER
RED
BLK
OVEN LAMP
THERMAL
CUT-OUT
Figure S-1. Pictorial Diagram
WHT
WHT
UPPER HEATER
OVEN THERMOSTAT
WHT
WHT
WHT
WHT
RED
RED
BLU
RED
BLU
RED
WHT
GRY
or
WHT
LOAD
H
N
POWER
TRANSFORMER
H.V. RECTIFIER
MAGNETRON
LOAD
WHT
GRY
or
SOURCE
HIGH VOLTAGE
CAPACITOR
HIGH VOLTAGE COMPONENTS
NOTE:
The grounding conductor of
the power supply cord has
been grounded by power
supply cord fixing screw.
The screw must allways be
kept tight.
POWER SUPPLY
CORD 120V 60Hz
NOTE:
The neutral (WHT) wire
must be connected to the
terminal with "N" mark on
the power supply cord.
FAN MOTOR
TEMPERATURE FUSE
(MAGNETRON)
RED
RED
BLK
THERMISTOR
WHT
RED
RED
RED
4
SP1
CN-A
RY5
BLK
BLK
RY2
RY2: PRIMARY
INTERLOCK
BRN
RELAY
CONTROL UNIT
To Air duct
G
CN-C
F
WH-B
E
2
C
1
D
3
3
B
SOURCE
1
2
CN-B
1
1
WHT
R-55TS-F
5
6
A
A
B
C
6
D
E
F
G
H
4
N.O.
N.O.
N.O.
COM
DOOR
SENSING
SW
CN-B
B3
B2
B1
N.O.
POWER
TRANSFORMER
UPPER
HEATER
COM
OVEN LAMP
TURENTABLE
MOTOR
COM
LOWER
HEATER
COM
A1
A5
10G471K
RY5
D25
NOTE
DU24D1-1P(R)M
RY2
DU24D1-1P(R)M
RY3
5
D4
Q26
KRA101M
D30
:check point
:IF NOT SPECIFIED 0.01uF/16V
:IF NOT SPECIFIED 1SS270A
C2
D80
C20
VR
50V/ 470u or 330u
KRA101M 0.1u
50V
Q21
D81
D82
Q25
KRA101M
KRA101M
Q23
KRC243M
Q22
Q24
C1
50V/ 01.u
Q2
KRA101M
KRA101M
50V/0.1u
1N4002N x4
C3
D2
:IF NOT SPECIFIED 1/4W +
_5%
J9
R20
R21
6
( ) : NOT INSERT PARTS
DU24D1-1P(R)M
RY1
DU24D1-1P(R)M
RY4
PCJ-124D3M
c
b
(J1)
VRS1
d
a
1
R1
47
R80
SP1
1W 360
R2
1W 360
4.7K
CN-C
R3
ZD1
R31
Q80
KRC105M
R4
R41
24KF
100K
R53
SW UNIT
3
3
C
SW1A
ENCODER
(C50)
0.047u /
16Vx2
4.7K
(C51)
50V/0.1u
50V/0.1u
100K
2
2
C53
C52
C54
R51
1
1
R45
10K
VC
R52
4.7K
WH-B
R50
12P HARNESS
15K
R30
1K
HZ4B3
4.7K
KRA101M
A1267Y
GND
10K x 3
I-1
CF1
6
6
8
7
SW9
BAKE
SW13
TOAST
SW10
MICRO
SNACKS
SW14
SW15
BAKE
GRILL
SW11
SW4
FROZEN
ENTREE
SW8
BEVERAGE
SW12
FRESH
VEGETABLES
8
7
STOP/
EXPRESS
CLEAR
DEFROST
SW3
SW2
SW1
POPTIMER/
REHEAT
CORN
CLOCK
SW5
SW6
SW7
5
START/
MINUTE
PLUS
5
CSTCC4.00MGW
4
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
4
VL2
VL1
AN7
AN6
AN5
AN4
AN3
AN2
P60
P61
P57
P56
P55
P54
P53
P52
P51
P50
P47
P46
P45
P44
INT1
INT0
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
SEG8
SEG9
SEG10
SEG11
SEG12
P35
P36
P37
P00
P01
P02
P03
P04
P05
P06
P07
P10
P11
P12
P13
P14
P15
P16
P17
9
9
12 12
11 11
10 10
100K
x4
REQUID CRYSTAL DISPLAY
(R68)
(R69)
(R70)
(R71)
5
Figure S-2. Control Unit Circuit
KRC105M
Q81
C6
50V/10u
Q40
Q1
(J2)
J3
POWER UNIT
(J4)
J5
D3
R40
D1
C2
C1
J6
J7
4
R5
10K
1K
3
D26 1N4002L
15K
C4
C30
50V/0.1u
C7
R6
R7
A3
D24
D21
D23
D22
35
(J80)
3
1.5K
1.5K
1.5K
1.5K
3.3K
VL3
COM0
COM1
COM2
COM3
AVSS
VREF
VCC
SEG0
SEG1
SEG2
SEG3
SEG4
SEG5
SEG6
SEG7
T1
4
A
B
C
SEG0
SEG1
SEG2
SEG3
SEG4
SEG5
SEG6
SEG7
SEG8
SEG9
SEG10
SEG11
SEG12
80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
2
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
1
R60
R61
R62
R63
H
P41
P40
RESET
P71
P70
XIN
XOUT
VSS
P27
P26
P25
P24
P32
P22
P21
P20
COM2
COM1
COM0
G
330p x 4
F
3
(C60)
(C61)
(C62)
(C63)
E
1.5K
1.5K
1.5K
1.5K
D
R8
B
2
R64
R65
R66
R67
1
R12
4.7K
A
PA111DR
R-55TS-F
6
A
B
C
6
D
E
F
G
H
R-55TS-F
2
1
4
3
6
5
A
A
SWITCH UNIT
WH-AA
LCD1
11
R7
13
C7
B Q21
R10
E
25
+
J8
Q22
_
E
31
D22
3
E
Q3
J9
D21
R21
E
B
RY1
D23
R9
RY3
R20
RY4
SW5
C6
B
Q80
_
E
B
C21
RY2
WH-B
1
SW12
REHEAT
Sn-Ag-Cu
SW7
C53
C52
7
R70
6
GRILL
SW5
26
32
C62
MICRO
C
D
Q23
12
BAKE
C63
R71
SW9
SW11
B
30
5
SW10
D81
B
B
D80
B
E
Q24
4
D
C4
R4
29
28
R41
WH-B
4
Q25
27
R12
J80
E
R5
E
ZD1
+
C5
DCUT
Q'TY/TIME
20
21
22
D82
23
Q81
C60
R68
SW1A
Q1
Q4
24
R3
R11
19
Sn-Ag-Cu
C30
E
R60
18
I-1
C20
CF1
R62
1
R50
C
R69
C61
C51
C50
3
R61
R52
R51
R53
2
R66
R65
R63
BAKE
R31
R8
SNACKS
TOAST
J6
J4
J2
R30
J7
J5
J3
C54
R45
SW15
17
R67
R64
SW13
16
B
12
14
15
SW14
R80
LD4
LD5
R6
WH-A
LD6
B
LD3
ZD3
B
LD2
10
Sn-Ag-Cu
LD1
POWER UNIT
E
E
D24
BEVERAGE
8
E
1 CN-C 2
B
D27
6
B
D26
4
START/MINUTEPLUS
VRS1
D3
34
STOP/CLEAR
D2
D1
B
E
E
J1
5
C3
CN-A
+
1
R1
1
G
F
D4
RY6
1
SW2
T1
3
CN-B 3
SW1
TIMER/CLOCK
1
D30
F
SW6
E
P
SW4
FRESH VEGETABLES
SW3
EXPRESS DEFROST
D25
S
FROZEN ENTREE
Q27
33
RY5
9
SW8
35
REHEAT
Q26
POPCORN
Q2
G
_
2
C2
37
B
R40
C1
Q40
E
36
B
SP1
R2
H
H
Figure S-3. Printed Wiring Board
1
2
4
3
36
5
6
R-55TS-F
PARTS LIST
Note: The parts marked “∆” may cause undue microwave exposure.
The parts marked “*” are used in voltage more than 250V.
The price codes marked "@" have been changed due to changing production to SATL.
REF. NO.
PART NO.
DESCRIPTION
Q'TY
CODE
ELECTRIC PARTS
1- 1
1- 2
1- 3
1- 4
1- 4
1- 5
1- 5
1- 5
1- 6
1- 6
1- 7
1- 8
1- 9
1-10
1-10
1-11
1-13
1-14
1-15
1-16
1-17
1-18
QSW-MA085WRE0
FFS-BA038WRKZ
FH-HZA082WREZ
FACCDA089WREZ
FACCDA086WREZ
RC-PZA041WRE0
RC-QZA313WRZZ
RC-QZA307WRZZ
RH-DXA001WRZZ
RH-DXA002WRZZ
RHET-A279WRZZ
RMOTEA420WRZZ
RMOTDA252WRZZ
RLMPTA082WRZZ
RLMPTA085WRZZ
RV-MZA261WRE0
RTRN-A719WRZZ
RTHM-A133WRZZ
RTHM-A132WRZZ
RHET-A278WRZZ
FPWBFA380WRKZ
QFS-TA013WRE0
Secondary interlock switch / Door sensing switch
Monitor fuse (15A) and monitor switch(V-5220Q) assembly
Thermistor assembly
Power supply cord
Power supply cord (Interchangeable)
High voltage capacitor
High voltage capacitor (Interchangeable)
High voltage capacitor (Interchangeable)
High voltage rectifier
"
"
" (Interchangeable) for production use
Lower heater
Fan motor
Turntable motor
Oven lamp
Oven lamp (Interchangeable)
Magnetron
Power transformer
Oven thermostat 150C
Thermal cut out 125C
Upper heater
Noise filter
Temperature fuse 150C (Magnetron)
2- 1
2- 2
2- 3
FDAI-A271WRKZ
GLEGPA091WREZ
GCABUA896WRPZ
Bottom plate assembly
Leg
Outer case cabinet
333333333-
1
2
3
4
5
6
7
8
9
DPWBFC384WRKZ
FKNBKA217WRKZ
FPNLCB799WRKZ
JBTN-B246WRFZ
JBTN-B247WRFZ
MSPRCA143WREZ
PCUSGA639WRPZ
PCUSGA640WRPZ
XEPS730P08000
Control unit
Timer knob assembly
Panel sub assembly
Open button
Select button
Button spring
LCD cushion A
LCD cushion B
Screw 3mm x 8mm
∆ 4- 1
PHOK-A132WRFZ
LBNDKA164WRPZ
PFPF-A220WREZ
PSLDHA180WRWZ
NFANJA050WREZ
xxxxxxxxxxxxx
LANGKA933WRPZ
LANGKB054WRPZ
FSFTTA043WREZ
LHLD-A220WRPZ
NGERHA136WRFZ
GGADUA002WREZ
PDUC-A846WRPZ
PCUSGA505WRP0
PSPA-A135WREZ
LANGKB056WRPZ
PCUSGA643WRPZ
LANGQA604WRPZ
LANGTA401WRPZ
PCUSGA530WRE0
LSTPPA212WRFZ
LANGKB053WRPZ
LANGKB048WRPZ
MHNG-A518WRPZ
MHNG-A519WRPZ
LANGKB046WRPZ
Latch hook
Capacitor band
Lower thermal insulation
Bottom reflector
Fan blade
Oven cavity assembly (Not replaceable part)
Sensor mounting angle
Shaft stopper
Turntable shaft assembly
Turntable motor mounting angle
Turntable gear A
Heater guard
Air duct
Cushion
Spacer
Insertion barrier A
Cushion
Thermistor angle
Chassis support
Cushion
Door stopper
Door insertion barrier
Fan duct
Lower oven hinge
Upper oven hinge
Heater fix angle left
*
*
*
*
*
∆*
*
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
AF
AP
AK
AS
AN
AS
AP
AX
AG
-AM
AU
AN
AL
AH
BF
BE
AM
AM
AN
AW
AG
1
4
1
AY
AC
BD
1
1
1
1
1
1
1
2
12
BL
AQ
BB
AH
AQ
AE
AD
AD
AA
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
AH
AK
AE
AM
AR
-AL
AM
AQ
AL
AH
AD
AH
AB
CABINET PARTS
CONTROL PANEL PARTS
OVEN PARTS
∆
4- 2
4- 3
4- 4
4- 5
4- 6
4- 7
4- 8
4- 9
4-10
4-11
4-12
4-13
4-14
4-15
4-16
4-17
4-18
4-19
4-20
4-21
4-22
4-23
4-24
4-25
4-26
37
AE
AE
AF
AL
AC
AC
AE
AP
AG
AG
AF
R-55TS-F
REF. NO.
4-27
4-28
4-29
4-30
4-31
4-32
4-33
4-34
4-35
4-36
4-37
4-38
4-39
4-40
PART NO.
LANGKB045WRPZ
PCUSGA630WRPZ
PDUC-A859WRPZ
PSKR-A396WRPZ
PSLDHA173WRPZ
PSLDHA175WRPZ
MSPRCA150WREZ
PCOVPA369WREZ
MLEVPA247WRFZ
GCOVAA321WRPZ
GCOVAA322WRPZ
PSKR-A395WRPZ
LANGQA591WRPZ
PCUSGA485WRE0
DESCRIPTION
Heater fix angle right
Cushion
Exhaust duct
Reflector right
Upper thermal cover
Left thermal cover
Turntable spring
Waveguide cover
Switch lever
Exhaust cover
Rear cover
Rear reflector
Noise filter angle
Cushion
∆ 5- 4
5555-
5
6
7
8
DDORFB080WRKZ
GCOVHA457WRFZ
LSTPPA221WRFZ
LSTPPA222WRFZ
FDORFA370WRKZ
MSPRTA218WREZ
PGLSPA591WREZ
XEPS740P10000
FWAKPA401WRKZ
Door assembly
Choke cover
Latch head
Glass stopper
Door panel
Latch spring
Front door glass
Screw : 4mm x 8mm
Door frame assembly
66666666-
1
2
3
4
5
6
7
8
FTNT-A048WRMZ
TINSEB028WRRZ
TLABMA911WRRZ
NTNT-A070WRH0
FW-VZC004WREZ
TCAUAA293WRRZ
TCAUAA265WRRZ
LBNDKA166WREZ
Turntable support
Operation manual
Menu label
Turntable
Main wire harness
Monitor caution
DHHS caution label
Wire holder
Q'TY
1
1
1
1
1
1
1
1
1
1
1
1
1
1
CODE
AL
AD
AN
AK
AK
AG
AF
AD
AF
AH
AR
AE
AN
AD
1
1
1
1
1
1
1
2
1
BM
AT
AH
AF
BD
AE
AY
AA
BK
1
1
1
1
1
1
1
1
AQ
AM
AE
AR
AZ
AF
AC
AD
2
3
3
2
5
6
4
1
2
2
2
4
4
1
5
1
19
12
1
1
AB
AB
AC
AB
AB
AC
AB
AB
AA
AC
DOOR PARTS
∆ 5
∆ 5- 1
∆ 5- 2
5- 3
MISCELLANEOUS
SCREWS,NUTS AND WASHERS
7- 1
7- 2
7- 3
7- 4
7- 5
7- 7
7- 8
7- 9
7-10
7-11
7-12
7-13
7-14
7-15
7-16
7-18
7-19
7-20
7-21
7-22
XTTS740P06000
XFPS740P10000
XHTS740P08000
XHPS740P08K00
XHPS730P06000
LX-BZA148WREZ
XHPS740P08000
LX-BZA128WRE0
LX-CZ0052WRE0
LX-CZA070WRE0
XFTS740P10000
XHTS740P08RV0
LX-BZA144WREZ
XOTWW40P10000
XHTS740P12RV0
XNEUW30-24000
XOTS740P08000
XOTS740P10000
XEPS740P08000
XOTS740P12000
Screw : 4mm x 6mm
Screw : 4mm x 10mm
Screw : 4mm x 8mm
Screw : 4mm x 8mm
Screw : 3mm x 6mm
Special screw
Screw : 4mm x 8mm
Special screw
Special screw
Special screw (Torx tamper proof screw)
Screw : 4mm x 10mm
Screw : 4mm x 8mm
Special screw
Screw : 4mm x 10mm
Screw : 4mm x 12mm
Nut : 3mm x 2,.4m
Screw : 4mm x 8mm
Screw : 4mm x 10mm
Screw : 4mm x 8mm
Screw : 4mm x 12mm
HOW TO ORDER REPLACEMENT PARTS
To have your order filled promptly and correctly, please furnish the following information.
1. MODEL NUMBER
2. REF. NO.
3. PART NO.
4. DESCRIPTION
Order Parts from the authorized SHARP parts Distributor for your area.
Defective parts requiring return should be returned as indicated in the Service Policy.
38
AG
AB
AA
AC
AB
AA
AA
AB
AA
R-55TS-F
2
1
4
3
OVEN AND CABINET PARTS
7-19
x2
A
7-11
2-3
7-5
7-19
x2
4-14
A
6
5
4-37
7-19
x2
6-7
4-32
4-29
B
7-1
7-14
4-31
7-19 B
x2
6-6
7-11
7-19
1-16
4-26
7-4
1-2
6-8
4-12
1-17
1-15
7-1
7-5
C
7-18
1-14
7-15
4-27
7-16
4-25
C
4-39
7-14
4-23
4-6
7-3
7-21
4-18
4-34
D
7-14
4-30
4-15
1-7
7-10
E
6-4
7-19
4-1
7-8
7-3
1-1
7-19
1-1
1-13
4-35
x3
4-20
E
4-19
1-18
1-2
4-3
4-17
4-13
7-14
4-4
7-3
1-3
7-9
D
1-11
1-10
7-8
7-7
7-19
7-5
7-19
6-1
4-33
F
4-7
7-7
4-38
7-16
1-4
7-13
4-11
G
4-10
4-8
1-9
7-2
7-2
x2
7-19
G
4-2
1-6
1-5
7-12
x2
7-16
4-28
7-20
2
1-8
7-13
4-22
7-7
1
7-4
4-24
7-16
H
F
7-7
2-1
4-9
7-19
4-36
2-2
2-2
7-20
7-20
x4
H
4-5
4-16
7-20
4-40
4
3
39
5
6
R-55TS-F
2
1
4
3
5
6
CONTROL PANEL PARTS
3-1
A
3-7
3-5
3-3
A
3-8
3-9
B
B
3-9
DOOR PARTS
C
C
3-2
4-21
5
3-4
D
5-1
5-7
3-6
D
5-3
E
E
5-7
5-4
5-6
F
F
5-2
5-5
MISCELLANEOUS
G
G
5-8
6-5
Actual wire harness may be different from illustration.
H
H
1
2
4
3
40
5
6
R-55TS-F
PACKING AND ACCESSORIES
TRAY PROTECT
(SPADPA642WREZ)
6-4 TURNTABLE
6-1 TURNTABLE SUPPORT
TRAY PAD ASSEMBLY
(SPADFA598WREZ)
WRAP COVER
(SSAKHA014WREZ)
WRAP COVER
(SSAKHA087WREZ)
CABINET COVER
(SPADPA632WREZ)
6-2 OPERATION MANUAL
6-3 MENU LABEL (inside operation manual)
PAD ASSEMBLY
(CPADBA327WRKZ)
Not replaceable items.
PACKING CASE
(FPAK-A554WRKZ)
41
R-55TS-F
COPYRIGHT © 2005 BY SHARP CORPORATION
ALL RIGHTS RESERVED.
No part of this publication may be reproduced,
stored in retrieval systems, or transmitted in any
form or by any means, electronic, mechanical,
photocopying, recording, or otherwise, without
prior written permission of the publisher.
2005 SHARP CORP. (12S1.695E) Printed in U.S.A