SHARP R8000G Service Manual
SERVICE MANUAL
COMMERCIAL
HIGH SPEED CONVECTION
MICROWAVE OVEN
R-8000G
SY313R8000GP/
MODEL
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
PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICE TO
AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY............................ INSIDE FRONT COVER
BEFORE SERVICING ............................................................................................................... INSIDE FRONT COVER
WARNING TO SERVICE PERSONNEL ........................................................................................................................ 1
MICROWAVE MEASUREMENT PROCEDURE ............................................................................................................ 2
FOREWORD AND WARNING ....................................................................................................................................... 3
PRODUCT SPECIFICATIONS ....................................................................................................................................... 4
GENERAL INFORMATION ........................................................................................................................................... 4
OPERATION ................................................................................................................................................................... 6
TROUBLESHOOTING GUIDE ..................................................................................................................................... 13
TEST PROCEDURE ..................................................................................................................................................... 15
TOUCH CONTROL PANEL .......................................................................................................................................... 25
PRECAUTIONS FOR USING LEAD-FREE SOLDER .................................................................................................. 29
PROCEDURE FOR CHECKING/ SETTING TOTAL OPERATION TIME .................................................................... 30
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ......................................................................... 31
SERVICE MAINTENANCE CLEANING ....................................................................................................................... 39
PICTORIAL DIAGRAM ................................................................................................................................................. 40
POWER UNIT, CPU UNIT AND CONTROL UNIT CIRCUIT ........................................................................................ 41
GRID ASSIGNMENT OF FLUORESENT DISPLAY TUBE .......................................................................................... 42
PRINTED WIRING BOARD .......................................................................................................................................... 42
PARTS LIST ................................................................................................................................................................. 44
PACKING AND ACCESSORIES .................................................................................................................................. 47
R-8000G
Page
SHARP CORPORATION
This document has been published to be used for after
sales service only.
The contents are subject to change without notice.
R-8000G
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.
WARNING TO SERVICE PERSONNEL
Don't Touch !
Danger High Voltage
Microwave ovens contain circuitry capable of producing very high voltage and current, contact with
following parts
fatal, electrical shock.
(Example)
High Voltage Capacitor, High Voltage Power Trans-
former, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..
Read the Service Manual carefully and follow all
instructions.
may result in a severe, possibly
R-8000G
Before Servicing
1. Disconnect the power supply cord , and then
remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
WARNING:RISK OF ELECTRIC SHOCK.
DISCHARGE THE HIGH-VOLTAGE
CAPACITOR BEFORE SERVICING.
The high-voltage capacitor remains charged about 60 seconds
after the oven has been switched off. Wait for 60 seconds and
then short-circuit the connection of the high-voltage capacitor
(that is the connecting lead of the high-voltage rectifier) against
the chassis with the use of an insulated screwdriver.
Whenever troubleshooting is performed the power supply must be
disconnected. It may, in some cases, be necessary to connect the
power supply after the outer case has been removed, in this event,
1. Disconnect the power supply cord, and then remove outer
case.
2. Open the door and block it open.
3. 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.
After repairing
1. Reconnect all leads removed from components during testing.
2. Reinstall the outer case (cabinet).
3. Reconnect the power supply cord after the outer case is
installed.
4. Run the oven and check all functions.
Microwave ovens should not be run empty. To test for the presence
of microwave energy within a cavity, place a cup of cold water on
the oven turntable, close the door and set the power to HIGH and
set the microwave timer for two (2) minutes. When the two minutes
has elapsed (timer at zero) carefully check that the water is now
hot. If the water remains cold carry out Before Servicing procedure and re-examine 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-8000G
MICROWAVE MEASUREMENT PROCEDURE
A. Requirements:
1) Microwave leakage limit (Power density limit): The power density of microwave radiation emitted by a microwave oven
should not exceed 1mW/cm2 at any point 5cm or more from the external surface of the oven, measured prior to acquisition
by a purchaser, and thereafter (through the useful life of the oven), 5 mW/cm2 at any point 5cm or more from the external
surface of the oven.
2) Safety interlock switches: Primary interlock relay and door sensing switch shall prevent microwave radiation emission
in excess of the requirement as above mentioned, secondary interlock switch shall prevent microwave radiation emission
in excess of 5 mW/cm2 at any point 5cm or more from the external surface of the oven.
B. Preparation for testing:
Before beginning the actual measurement of leakage, proceed as follows:
1) Make sure that the actual instrument is operating normally as specified in its instruction booklet.
Important:
Survey instruments that comply with the requirement for instrumentation as prescribed by the performance standard for
microwave ovens, 21 CFR 1030.10(c)(3)(i), must be used for testing.
2) Place the oven tray in the oven cavity.
3) Place the load of 275±15 ml (9.8 oz) of tap water initially at 20±5˚C (68˚F) in the center of the oven cavity.
The water container shall be a low form of 600 ml (20 oz) beaker with an inside diameter of approx. 8.5 cm (3-1/2 in.)
and made of an electrically nonconductive material such as glass or plastic.
The placing of this standard load in the oven is important not only to protect the oven, but also to insure that any leakage
is measured accurately.
4) Set the cooking control on Full Power Cooking Mode.
5) Close the door and select a cook cycle of several minutes. If the water begins to boil before the survey is completed,
replace it with 275 ml of cool water.
C. Leakage test:
Closed-door leakage test (microwave measurement)
1) Grasp the probe of the survey instrument and hold it perpendicular to the gap between the door and the body of the oven.
2) Move the probe slowly, not faster than 1 in./sec. (2.5 cm/sec.) along the gap, watching for the maximum indication on
the meter.
3) Check for leakage at the door screen, sheet metal seams and other accessible positions where the continuity of the metal
has been breached (eg., around the switches, indicator, and vents).
While testing for leakage around the door pull the door away from the front of the oven as far as is permitted by the closed
latch assembly.
4) Measure carefully at the point of highest leakage and make sure that the highest leakage is no greater than 4mW/cm2,
and that the secondary interlock switch does turn the oven OFF before any door movement.
NOTE: After servicing, record data on service invoice and microwave leakage report.
2
SERVICE MANUAL
COMMERCIAL
HIGH SPEED CONVECTION
MICROWAVE OVEN
R-8000G
FOREWORD
R-8000G
PRODUCT DESCRIPTION
GENERAL INFORMATION
This Manual has been prepared to provide Sharp Electronics Corp.
Service Personnel with Operation and Service Information for the
SHARP COOMERCIAL HIGH SPEED CONVECTION MICROWAVE
OVEN, R-8000G.
It is recommended that service personnel carefully study the entire text of this
manual so that they will be qualified to render satisfactory customer service.
Check the interlock switches and the door seal carefully. Special attention
should be given to avoid electrical shock and microwave radiation hazard.
WARNING
Never operate the oven until the following points are ensured.
(A) The door is tightly closed.
(B) The door brackets and hinges are not defective.
(C) The door packing is not damaged.
(D) The door is not deformed or warped.
(E) There is no other visible damage with the oven.
Servicing and repair work must be carried out only by trained
service personnel.
DANGER
Certain initial parts are intentionally not grounded and present
a risk of electrical shock only during servicing. Service
personnel - Do not contact the following parts while the
appliance is energized;
High Voltage Capacitor, Power Transformer, Magnetron, High
Voltage Rectifier Assembly, High Voltage Harness;
If provided, Vent Hood, Fan assembly, Cooling Fan Motor.
OPERATION
TROUBLESHOOTING GUIDE
AND TEST PROCEDURE
TOUCH CONTROL PANEL
COMPONENT REPLACEMENT AND
ADJUSTMENT PROCEDURE
WIRING DIAGRAM
PARTS LIST
All the parts marked “*” on parts list are used at voltages more than
250V.
Removal of the outer wrap gives access to voltage above 250V.
All the parts marked “∆” on parts list may cause undue microwave
exposure, by themselves, or when they are damaged, loosened
or removed.
SHARP ELECTRONICS CORPORATION
SHARP PLAZA, MAHWAH,
NEW JERSEY 07430-2135
3
R-8000G
SPECIFICATION
ITEM DESCRIPTION
Power Requirements 208 Volts
9.0 Amperes (Microwave) / 14.0 Amperes (Convection)/ 16.0 Amperes (Speed Cooking)
60 Hertz / Single phase, 3 wire grounded
Power Output 1000 watts (IEC Test Procedure)
Operating frequency of 2450MHz
Top Heater Power Output 1500 Watts
Side Heater Power Output 1200 Watts
Case Dimensions Width 21-5/8" Height 16-1/2" Depth 24-1/4"
Cooking Cavity Dimensions Width 16-1/8"
(1.1 Cubic Feet ) Height 8-3/8"
Depth 13-5/8"
Control Complement Touch Control System
Timer (0 - 99 min. 99 seconds)
Microwave Power for Variable Cooking
Repetition Rate;
100 PERCENT ......................................... Full power throughout the cooking time
90 PERCENT ............................................................approx. 90% of Full Power
80 PERCENT ............................................................approx. 80% of Full Power
70 PERCENT ............................................................approx. 70% of Full Power
60 PERCENT ............................................................approx. 60% of Full Power
50 PERCENT ............................................................approx. 50% of Full Power
40 PERCENT .............................................................approx. 40% of Full Power
30 PERCENT .............................................................approx. 30% of Full Power
20 PERCENT ............................................................approx. 20% of Full Power
10 PERCENT .............................................................approx. 10% of Full Power
0 PERCENT .......................................... No power throughout the cooking time
NOTE: Internal capacity is calculated by measuring maximum width,
depth and height. Actual capacity for holding food is less.
Oven temperature setting
100˚F, 150˚F, 275˚F, 300˚F, 325˚F, 375˚F, 400˚F, 425˚F, 450˚F
AUTOMATIC COOKING pads, SELECTA TIME pad, SELECTA POWER pad
CUSTOM HELP pad, Number pads, OVEN READY ON/OFF pad, SELECTA PROGRAM pad
SET pad, DOUBLE/TRIPLE QTY pad, START/MINUTES PLUS pad, STOP/CLEAR pad
Oven Cavity Light Yes
Safety Standard UL Listed FCC Authorized
DHHS Rules, CFR, Title 21, Chapter 1, Subchapter J , NSF Certified
GENERAL INFORMATION
GROUNDING INSTRUCTIONS
This appliance must be grounded. This oven is equipped with a cord having a grounding wire with a 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 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 208 volt 60 Hz, AC only, 20 amp. or more protected electrical supply. It is recommended that a separate
circuit serving only this appliance be provided. The 208 volt circuit is absolutely necessary for optimum cooking performance. The oven
is equipped with a 3-prong grounding plug. It must be plugged into a wall receptacle that is properly installed and grounded.
4
R-8000G
Receptacle Box Cover
3-Pronged NEMA plug
(6-20P)
3-Pronged, NEMA receptacle
(6-20R)
9
18
17
9
15
16
8
7
3
5
41
3
6
2
12
13
11
10
14
Extension Cord
If it is necessary to use an extension cord, use only a 3-wire extension cord that has a 3-blade
grounding plug and a 3-slot receptacle that will accept the plug on the high speed oven. The
marked rating of the extension cord should be AC 208 volt, 20 amp. or more. Be careful not to
drape the cord over the countertop or table where it can be pulled on by children or tripped over
accidentally.
CAUTION: DO NOT UNDER ANY CIRCUMSTANCES CUT OR REMOVE THE ROUND GROUNDING PRONG FROM THIS PLUG.
OVEN DIAGRAM
1 Door handle
To open the door, pull the handle down and forward. Never hold the door handle when moving the oven.
2 Oven door with see-through window
3 Safety door latches
The oven will not operate unless the door is securely closed.
4 Door hinges
5 Door seals and sealing surfaces
6 Turntable motor shaft
7 Removable turntable support
Carefully place the turntable support in the center of the oven floor. After cooking, always clean the turntable support, especially around
the rollers. These must be free from food splashes and grease. Built-up splashes or grease may overheat and cause arcing, begin
to smoke or catch fire.
8 Removable turntable
Place the turntable on the turntable support securely. The turntable will rotate clockwise or counterclockwise. Only remove for cleaning.
9 Ventilation openings
10 Oven light
It will light when oven is operating or door is open.
11 Waveguide cover
12 Auto-Touch control panel
13 Time display: 99 minutes, 99
seconds
14 Convection air openings
15 Removable low rack
16 Removable high rack
17 Ventilation cover
18 Oven light access cover
TOUCH CONTROL PANEL
5
R-8000G
OPERATION
DESCRIPTION OF OPERATING SEQUENCE
The following is a description of component functions during oven
operation.
OFF CONDITION
Closing the door activates the door sensing switch, secondary
interlock switch and 3rd. latch switch. (In this condition, the monitor
switch contacts are opened.)
When oven is plugged in, 208 volts A.C. 60 Hz is supplied to the
control unit. (Figure O-1).
1. The display will show " . ".
NOTE: When the door is opened, the oven lamp comes on.
MICROWAVE COOKING CONDITION
Press the SELECTA TIME pad. Program desired cooking time by
touching the NUMBER pads and the power level pad by touching
SELECTA POWER 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 CONNECTED COMPONENTS
RY-1 Oven lamp/Turntable motor
RY-2 Power transformer
RY-5 Fan motor
2. 208 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 2300 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 feed-box,
and then into the cavity where the food is placed to be cooked.
5. Upon completion of the cooking time, the power transformer,
oven lamp, etc. are turned off, and the generation of microwave
energy is stopped. The oven will revert to the OFF condition.
6. When the door is opened during a cook cycle, monitor switch,
door sensing switch, relay (RY1), the primary interlock relay
(RY2) and the secondary interlock switch are activated with the
following results. The circuits to the turntable motor, the cooling
fan motor, and the high 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 is electrically monitoring the operation of
the primary interlock relay (RY2) and the secondary interlock
switch and is mechanically associated with the door so that it
will function in the following sequence.
(1) When the door opens from a closed position, the primary
interlock relay (RY2), the secondary interlock switch and the
3rd. latch switch open their contacts. And contacts of the relay
(RY1) remain closed. Then the monitor switch contacts close.
(2) When the door is closed from the open position, the monitor
switch contacts first open and the 3rd. latch switch contacts
close, and then the contacts of the secondary interlock switch
close. And contacts of the relay (RY1) open.
If the primary interlock relay (RY2) and the secondary interlock
switch fail with their contacts closed when the door is opened, the
closing of the monitor switch contacts will form a short circuit
through the monitor fuse, relay (RY1), primary interlock relay
(RY2) and the secondary interlock switch, causing the monitor
fuse to blow.
POWER LEVEL P-0 TO P-90 COOKING
When Variable Cooking Power is programmed, the 208 volts A.C.
is supplied to the power transformer intermittently through the
contacts of relay (RY-2). RY-2 is operated by the control unit within
an varying time base. Microwave power operation is as follows:
VARI-MODE ON TIME OFF TIME
100 PERCENT (100% power) 32 sec. 0 sec.
90 PERCENT (approx. 90% power) 30 sec. 2 sec.
80 PERCENT (approx. 80% power) 26 sec. 6 sec.
70 PERCENT (approx. 70% power) 24 sec. 8 sec.
60 PERCENT (approx. 60% power) 22 sec. 10 sec.
50 PERCENT (approx. 50% power) 18 sec. 14 sec.
40 PERCENT (approx. 40% power) 16 sec. 16 sec.
30 PERCENT (approx. 30% power) 12 sec. 20 sec.
20 PERCENT (approx. 20% power) 8 sec. 24 sec.
10 PERCENT (approx. 10% power) 6 sec. 26 sec.
0 PERCENT (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.
EXPRESS DEFROST COOKING
This is the multiple sequence cooking composed of low microwave
power.
NORMAL CONVECTION COOKING CONDITION
Touch SELECTA PROGRAM pad 3 times. Then touch SET pad.
Program desired oven temperature by touching the SET pad.
Enter cooking time by touching number pads. When the START
pad is touched, the following operations occur: (Figure O-3)
1. The coil of shut-off relays (RY1, RY3 and RY5) are energized,
the oven lamp, cooling fan motor, turntable motor and jet motor
are turned on.
2. The solid-state relays are energized by the control unit and the
main supply voltage is applied to the top and side heating
elements.
3. When the oven temperature reaches the selected preheat
temperature, the following operations occur:
3-1 The solid-state relays are de-energized by the control unit
temperature circuit and thermistor, opening the circuit to
the heating elements.
3-2 The oven will continue to function for 30 minutes, turning
the heating elements on and off, as needed to maintain the
selected preheat temperature. The oven will shutdown
completely after 30 minutes
4. Open the door and place food in the oven. Close door. Touch
the START pad. (Figure O-3)
5. The numbers on the digital read-out start to count down to zero.
6. The oven lamp, turntable motor, cooling fan motor and jet
motor are energized.
6
R-8000G
JET MOTOR
THERMISTOR
Sensing
Voltage
ON
OFF
ON
OFF
ON
OFF
023283132 (sec.) 64 (sec.)
3 sec.
Sensing the voltage across temperature measurement circuit.
3 sec.
7. The solid-state relays 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.
8. Upon completion of the cooking time, the audible signal will
sound, and oven lamp, turntable motor, cooling fan motor and jet
motor are de-energized. At the end of the convection cycle, if the
cavity air temperature is above 230˚F, the circuit to RY5 will be
maintained (by the thermistor circuit) to continue operation of the
cooling fan motor until the temperature drops below 195˚F, at
which time the relay will be de-energized, turning off the fan
motor. Relay RY3 will however, open as soon as the convection
cycle has ended, turning off the convection fan motor.
SPEED BAKE COOKING
Touch SELECTA PROGRAM pad 8 times and touch SET pad.
Then touch SET pad to select desired temperature. Enter cooking
time. When the START pad is touched, the following operations
occur: (Figure O-3)
1. The contacts of the relays RY1, RY3 and RY5 are closed, and
the oven lamp, turntable motor, jet motor and fan motors are
energized.
NOTE : The rotate direction of the jet motor is the same as one of
the convection cooking.
2. The solid-state relays are energized and the main supply
voltage is applied to the top and side heating elements.
NOTE : After cooking, the operation of the fan motors is the
same as one of the convection cooking.
HIGH SPEED GRILL/ SPEED GRILL COOKING
Touch SELECTA PROGRAM pad 6 times and touch SET pad.
Enter cooking time. When the START pad is touched, the following
operations occur: (Figure O-4)
1. The contacts of the relays RY1, RY3, RY5 and RY6 are closed,
and the oven lamp, turntable motor, jet motor and fan motors
are energized.
NOTE : The rotate direction of the jet motor is reverse to one
of the convection cooking by the relay RY6.
2. The solid-state relays are energized and the main supply
voltage is applied to the top and side heating elements.
NOTE : After cooking, the operation of the fan motors is the
same as one of the convection cooking.
AUTOMATIC COOKING
Automatic cooking will automatically compute the oven temperature, microwave power and cooking time. And the oven will cook
according to the special cooking sequence.
FIRE SENSING FEATURE (MICROWAVE MODE)
This model incorporates a sensing feature which will stop the
oven's operation if there is a fire in the oven cavity during microwave cooking. This fire sensing feature will operate when the
microwave power level is set to 80% or more. This is accomplished
by the LSI repeatedly measuring the voltage across the temperature measurement circuit (thermistor) during it's 32-seconds time
base comparing the obtained voltage measurements. If the most
recent voltage measured is 300 mV greater than the previous
voltage measured, the LSI judges it as a fire in the oven cavity and
switches off the relays to the power transformer, fan motor and jet
motor. The LSI also stops counting down and closes the damper
door so that no fresh air will enter the oven cavity. Please refer to
the following section for a more detailed description.
Operation
Please refer to the timing diagrams below.
1. The fire sensing will start after 5 minutes when the oven is
started.
2. The thermistor operates within a 32-seconds time base and it
is energized for three (3) seconds and off for 29 seconds. Two
(2) seconds after the thermistor is energized, the voltage
across the temperature measurement circuit is sampled by the
LSI and twenty five (25) seconds after the thermistor is cut off
the LSI turns on the convection fan for three (3) seconds.
3. The above procedure is repeated. If the difference between the
first voltage measured (in step 1) and the voltage measured
when the procedure is repeated (step 2) is greater than 300 mV
the LSI makes the judgment that there is a fire in the oven cavity
and will switch off the relays to the power transformer, fan motor
and jet motor. The LSI also stops counting down and closes the
damper door so that no fresh air will enter the oven cavity.
4. Once the fire sensor feature has shut the unit down, the
programmed cooking cycle may be resumed by pressing the
"START" pad or the unit may be reset by pressing the "CLEAR"
pad.
HIGH SPEED GRILL WITH MICRO/ SPEED GRILL
WITH MICRO/ SPEED ROAST COOKING
Touch SELECTA PROGRAM pad 9 times and touch SET pad.
Then touch SET pad to select desired temperature. Enter cooking
time. When the START pad is touched, the following operations
occur: (Figure O-5)
1. The contacts of the relays RY1, RY3 and RY5 are closed, and
the oven lamp, turntable motor, jet motor and fan motors are
energized.
NOTE : The rotate direction of the jet motor is the same as one
of the convection cooking for the first time. But for the
last 15 minutes, the direction is reverse by the relay
2. The solid-state relays and relay RY2 are energized alternately,
and the main supply voltage is applied to the top and side
heating elements and the power transformer alternately.
NOTE : After cooking, the operation of the fan motors is the
RY6.
same as one of the convection cooking.
FAN MOTOR OPERATION
After cooking is completed, the fan motors will continue for 1
minute. At the end of the cooking cycle, if the cavity air temperature
is above 230˚F, the circuit to RY5 will be maintained (by the
thermistor circuit) to continue operation of the cooling fan motor until
the temperature drops below 195˚F, at which time the relay will be deenergized, turning off the fan motor.
7
R-8000G
SCHEMATIC DIAGRAM
NOTE: CONDITION OF OVEN
SCHEMATIC
1. DOOR CLOSED.
2. . APPEARS ON DISPLAY.
NOISE FILTER
BLK
L
MONITOR
FUSE
20A
60Hz
~
208V
RESISTO 10MΩ 1/2W
LINE BYPASS CAPACITOR
0.0033 µF 250V
NOISE SUPRESSION COIL
LINE CROSS CAPACITOR 1.0µF 275V
RESISTO 680kΩ 1/2W
LINE BYPASS CAPACITOR
L
WHT GRY
0.0033 µF 250V
RED
T/C TRANSFORMER
A8 A6 A4 A3 A2E1A1 D9
CONTROL UNIT
B1
B2
B3 B4
DOOR
SENSING
SWITCH
THER-
MISTOR
Figure O-1. Oven Schematic-OFF Condition
NOTE: " " indicates components with potential above 250V.
MAGNETRON
TEMPERATURE
FUSE 150˚C
TOP HEATER
THERMAL
CUT-OUT 170˚C
RY6
D7D1
D5 D3
JET MOTOR CAPACITOR
SECONDARY INTERLOCK SWITCH
3RD. LATCH SWITCH
COM.
RY3
JET MOTOR
SIDE HEATER
THERMAL
CUT-OUT 150˚C
COM.
RY5
E3
JM
FM
COM.
RY1
N.O.
FM
FAN MOTOR
N.O.
PRIMARY
INTERLOCK RELAY
C1
RY2
C2
C3
COM.
OVEN LAMP
SOLID-STATE RELAY
SOLID-STATE RELAY
OL
TTM
TURNTABLE MOTOR
FUSE
F10A
POWER TRANSFORMER
SIDE HEATIMG ELEMENT
TOP HEATIMG ELEMENT
MONITOR SWITCH
WITH 160˚C THERMOSTAT
IN PRIMARY WINDING
CAPACITOR
1µ AC 2300V
H.V. RECTIFIER
MAGNETRON
SCHEMATIC (MICROWAVE TIME COOKING)
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. "SELECTA TIME" PAD TOUCHED.
3. COOKING TIME PROGRAMMED.
4. "START" PAD TOUCHED.
NOISE FILTER
BLK
L
MONITOR
FUSE
20A
60Hz
~
208V
RESISTO 10MΩ 1/2W
NOISE SUPRESSION COIL
LINE CROSS CAPACITOR 1.0µF 275V
RESISTO 680kΩ 1/2W
L
WHT GRY
RED
A8 A6 A4 A3 A2E1A1 D9
LINE BYPASS CAPACITOR
0.0033 µF 250V
LINE BYPASS CAPACITOR
0.0033 µF 250V
T/C TRANSFORMER
B1
B2
B3 B4
DOOR
SENSING
SWITCH
CONTROL UNIT
D7D1
THER-
MISTOR
NOTE: CONDITION OF OVEN
SCHEMATIC (EXPRESS DEFROST)
1. DOOR CLOSED.
2. "SELECTA PROGRAM" PAD TOUCHED TWICE.
3. "SET" PAD TOUCHED.
4. FOOD WEIGHT ENTERED.
5. "START" PAD TOUCHED.
MAGNETRON
TEMPERATURE
FUSE 150˚C
TOP HEATER
THERMAL
CUT-OUT 170˚C
RY6
D5 D3
JET MOTOR CAPACITOR
SECONDARY INTERLOCK SWITCH
3RD. LATCH SWITCH
COM.
RY3
JET MOTOR
SIDE HEATER
THERMAL
CUT-OUT 150˚C
COM.
RY5
E3
JM
FM
COM.
RY1
N.O.
FM
FAN MOTOR
N.O.
PRIMARY
INTERLOCK RELAY
C1
RY2
C2
C3
COM.
OVEN LAMP
SOLID-STATE RELAY
SOLID-STATE RELAY
OL
TTM
TURNTABLE MOTOR
FUSE
F10A
POWER TRANSFORMER
TOP HEATIMG ELEMENT
SIDE HEATIMG ELEMENT
MONITOR SWITCH
WITH 160˚C THERMOSTAT
IN PRIMARY WINDING
CAPACITOR
1µ AC 2300V
H.V. RECTIFIER
MAGNETRON
Figure O-2. Oven Schematic-Microwave or Express Defrost Cooking Condition
8
R-8000G
NOTE: CONDITION OF OVEN
SCHEMATIC (CONVECTION)
1. DOOR CLOSED.
2. "SELECTA PROGRAM" PAD TOUCHED 3 TIMES.
3. "SET" PAD TOUCHED.
4. DESIRED TEMPERATURE SELECTED WITH "SET" PAD.
5. COOKING TIME PROGRAMMED.
6. "START" PAD TOUCHED.
NOISE FILTER
BLK
L
MONITOR
FUSE
20A
60Hz
~
208V
RESISTO 10MΩ 1/2W
NOISE SUPRESSION COIL
LINE CROSS CAPACITOR 1.0µF 275V
RESISTO 680kΩ 1/2W
L
WHT GRY
RED
T/C TRANSFORMER
A8 A6 A4 A3 A2E1A1 D9
LINE BYPASS CAPACITOR
0.0033 µF 250V
B1
DOOR
SENSING
SWITCH
LINE BYPASS CAPACITOR
0.0033 µF 250V
B2
CONTROL UNIT
B3 B4
THER-
MISTOR
MAGNETRON
TEMPERATURE
FUSE 150˚C
TOP HEATER
THERMAL
CUT-OUT 170˚C
RY6
D7D1
D5 D3
JET MOTOR
JET MOTOR CAPACITOR
SECONDARY INTERLOCK SWITCH
3RD. LATCH SWITCH
NOTE: CONDITION OF OVEN
SCHEMATIC (SPEED BAKE)
1. DOOR CLOSED.
2. "SELECTA PROGRAM" PAD TOUCHED 8 TIMES.
3. "SET" PAD TOUCHED.
4. DESIRED TEMPERATURE SELECTED WITH "SET" PAD.
5. COOKING TIME PROGRAMMED.
6. "START" PAD TOUCHED.
FUSE
SIDE HEATER
THERMAL
CUT-OUT 150˚C
COM.
RY5
RY3
JM
E3
COM.
FM
COM.
RY1
N.O.
FM
FAN MOTOR
N.O.
PRIMARY
INTERLOCK RELAY
C1
RY2
C2
C3
COM.
OVEN LAMP
SOLID-STATE RELAY
SOLID-STATE RELAY
OL
TTM
TURNTABLE MOTOR
F10A
POWER TRANSFORMER
TOP HEATIMG ELEMENT
SIDE HEATIMG ELEMENT
MONITOR SWITCH
WITH 160˚C THERMOSTAT
IN PRIMARY WINDING
CAPACITOR
1µ AC 2300V
MAGNETRON
H.V. RECTIFIER
Figure O-3. Oven Schematic-Normal Convection or Speed Bake Cooking Condition
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. "SELECTA PROGRAM" PAD TOUCHED 4 TIMES.
3. "SET" PAD TOUCHED.
4. COOKING TIME PROGRAMMED.
5. "START" PAD TOUCHED.
BLK
60Hz
~
208V
WHT GRY
SCHEMATIC (HIGH SPEED GRILL)
NOISE FILTER
L
MONITOR
FUSE
20A
RESISTO 10MΩ 1/2W
LINE BYPASS CAPACITOR
0.0033 µF 250V
NOISE SUPRESSION COIL
LINE CROSS CAPACITOR 1.0µF 275V
RESISTO 680kΩ 1/2W
LINE BYPASS CAPACITOR
L
0.0033 µF 250V
RED
T/C TRANSFORMER
A8 A6 A4 A3 A2E1A1 D9
CONTROL UNIT
B1
B2
B3 B4
DOOR
SENSING
SWITCH
THER-
MISTOR
NOTE: CONDITION OF OVEN
SCHEMATIC (SPEED GRILL)
1. DOOR CLOSED.
2. "SELECTA PROGRAM" PAD TOUCHED 6 TIMES.
3. "SET" PAD TOUCHED.
4. COOKING TIME PROGRAMMED.
5. "START" PAD TOUCHED.
MAGNETRON
TEMPERATURE
FUSE 150˚C
TOP HEATER
THERMAL
CUT-OUT 170˚C
RY6
D7D1
D5 D3
JET MOTOR CAPACITOR
SECONDARY INTERLOCK SWITCH
3RD. LATCH SWITCH
COM.
RY3
JET MOTOR
SIDE HEATER
THERMAL
CUT-OUT 150˚C
COM.
RY5
E3
JM
FM
COM.
RY1
N.O.
FM
FAN MOTOR
N.O.
PRIMARY
INTERLOCK RELAY
C1
RY2
C2
C3
COM.
OVEN LAMP
SOLID-STATE RELAY
SOLID-STATE RELAY
OL
TTM
TURNTABLE MOTOR
FUSE
F10A
POWER TRANSFORMER
SIDE HEATIMG ELEMENT
TOP HEATIMG ELEMENT
MONITOR SWITCH
WITH 160˚C THERMOSTAT
IN PRIMARY WINDING
CAPACITOR
1µ AC 2300V
H.V. RECTIFIER
MAGNETRON
Figure O-4. Oven Schematic-High Speed Grill or Speed Grill Cooking Condition
9
R-8000G
NOTE: CONDITION OF OVEN
SCHEMATIC (HIGH SPEED GRILL WITH MICRO)
1. DOOR CLOSED.
2. "SELECTA PROGRAM" PAD TOUCHED 5 TIMES.
3. "SET" PAD TOUCHED.
4. COOKING TIME PROGRAMMED.
5. POWER LEVEL PROGRAMMED WITH "SELECTA POWER" PAD.
6. "START" PAD TOUCHED.
SCHEMATIC (SPEED ROAST)
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. "SELECTA PROGRAM" PAD TOUCHED 9 TIMES.
3. "SET" PAD TOUCHED.
4. DESIRED TEMPERATURE SELECTED WITH "SET" PAD.
5. COOKING TIME PROGRAMMED.
6. "START" PAD TOUCHED.
NOTE: The contacts of relay RY6 will contact D3 at the 1st.
stage only.
NOISE FILTER
BLK
L
MONITOR
FUSE
20A
60Hz
~
208V
RESISTO 10MΩ 1/2W
NOISE SUPRESSION COIL
LINE CROSS CAPACITOR 1.0µF 275V
RESISTO 680kΩ 1/2W
L
WHT GRY
RED
T/C TRANSFORMER
A8 A6 A4 A3 A2E1A1 D9
LINE BYPASS CAPACITOR
0.0033 µF 250V
B1
DOOR
SENSING
SWITCH
LINE BYPASS CAPACITOR
0.0033 µF 250V
B2
CONTROL UNIT
B3 B4
THER-
MISTOR
TOP HEATER
THERMAL
CUT-OUT 170˚C
RY6
D7D1
D5 D3
JET MOTOR CAPACITOR
SECONDARY INTERLOCK SWITCH
3RD. LATCH SWITCH
NOTE: CONDITION OF OVEN
SCHEMATIC (HIGH SPEED GRILL WITH MICRO)
1. DOOR CLOSED.
2. "SELECTA PROGRAM" PAD TOUCHED 7 TIMES.
3. "SET" PAD TOUCHED.
4. COOKING TIME PROGRAMMED.
5. POWER LEVEL PROGRAMMED WITH "SELECTA POWER" PAD.
6. "START" PAD TOUCHED.
NOTE: " " indicates components with potential above 250V.
MAGNETRON
TEMPERATURE
FUSE 150˚C
JET MOTOR
SIDE HEATER
THERMAL
CUT-OUT 150˚C
COM.
RY3
JM
RY5
E3
COM.
FM
COM.
RY1
N.O.
FM
FAN MOTOR
N.O.
PRIMARY
INTERLOCK RELAY
C1
RY2
C2
C3
COM.
OVEN LAMP
SOLID-STATE RELAY
SOLID-STATE RELAY
OL
TTM
TURNTABLE MOTOR
FUSE
F10A
POWER TRANSFORMER
SIDE HEATIMG ELEMENT
TOP HEATIMG ELEMENT
MONITOR SWITCH
WITH 160˚C THERMOSTAT
IN PRIMARY WINDING
CAPACITOR
1µ AC 2300V
MAGNETRON
H.V. RECTIFIER
Figure O-5. Oven Schematic-High Speed Grill with Micro, Speed Grill with Micro or Speed Roast Cooking Condition
10
DESCRIPTION AND FUNCTION OF COMPONENTS
R-8000G
DOOR OPEN MECHANISM
The door is opened by pulling the door handle down and forward,
referring to the figure D-1. When the door handle is pulled down,
the latch heads are moved upward. And then when the door handle
is pulled forward, the latch heads are released from the latch hooks
right and left. Now, the door will open.
Monitor switch
Latch hook left
Latch
head
Figure D-1. Door Open Mechanism
Secondary
interlock switch
Latch hook right
Latch
head
3rd. latch
switch
Door
sensing switch
DOOR SENSING AND SECONDARY INTERLOCK
SWITCHES
The door sensing switch in the primary interlock system is mounted
in the lower position on the latch hook right, the secondary interlock
switch is mounted in the lower position on the latch hook left. They
are activated by the latch heads on the door. When the door is
opened, the switches interrupt the circuit to all components except
for the oven lamp. A cook cycle cannot take place until the door is
firmly closed thereby activating both interlock switches. The primary
interlock system consists of the door sensing switch and primary
interlock relay located on the control circuit board.
MONITOR SWITCH
The monitor switch is mounted on the upper position of latch hook
left. It is activated (the contacts opened) by the left latch head 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 and secondary interlock switch fail to
open when the door is opened.
Functions:
1. When the door is opened, the monitor switch contact close (to
the ON condition) due to their being normally closed. At this
time the door sensing and secondary interlock switches are in
the OFF condition (contacts open) due to their being normally
open contact switches.
2. As the door goes to a closed position, the monitor switch
contacts are first opened and then the door sensing switch and
the secondary interlock switch contacts close. (On opening the
door, each of these switches operate inversely.)
3. If the door is opened, and the primary interlock relay and
secondary interlock switch contacts fail to open, the monitor
fuse blows simultaneously with closing of the monitor switch
contacts.
CAUTION: BEFORE REPLACING A BLOWN MONITOR FUSE
TEST THE DOOR SENSING SWITCH, PRIMARY
INTERLOCK RELAY, 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.
3RD. LATCH SWITCH
The 3rd. latch switch is mounted on the upper position of the latch
hook right. When the oven door is opened, the switch interrupt the
circuit to the top and side heating elements.
THERMISTOR
The thermistor is a negative temperature coefficient type. The
temperature in the oven cavity is detected through the resistance
of the thermistor, and then the control unit causes the heater relay
to operate, thus the current to the heating elements is turned ON/
OFF. If the convection cooking or some cooking modes which use
the top / side heating elements is started and the oven temperature
does not rise above 100˚F (37.8˚C), the control unit will stop the
oven after 10 minutes. In this case, the thermistor may be opened.
MAGNETRON TEMPERATURE FUSE.
The temperature fuse located on the waveguide flange 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.
Under normal operation, the temperature fuse remains closed.
However, when abnormally high temperatures are reached within
the magnetron, the temperature fuse will open at 302˚F(150˚C)
causing the oven to shut down.
TOP HEATER THERMAL CUT-OUT
The thermal cut-out located on the thermal cover upper is designed
to prevent damage to the top heating element unit if an over heated
condition develops in the top heating element unit due to convection fan failure, thermistor failure, obstructed air ducts, dirty or
blocked air intake, etc.
Under normal operation, the thermal cut-out remains closed.
However, when abnormally high temperature are reached within
the top heating element unit, the thermal cut-out will open at 338˚F
(170˚C) causing the oven to shut down. When the thermal cut-out
has cooled, the thermal cut-out closes at 311˚F(155˚C).
SIDE HEATER THERMAL CUT-OUT
The thermal cut-out located on the thermal cover left is designed
to prevent damage to the side heating element unit if an over
heated condition develops in the side heating element unit due to
convection fan failure, thermistor failure, obstructed air ducts, dirty
or blocked air intake, etc.
Under normal operation, the thermal cut-out remains closed.
However, when abnormally high temperature are reached within
the side heating element unit, the thermal cut-out will open at 302˚F
(150˚C) causing the oven to shut down. When the thermal cut-out
has cooled, the thermal cut-out closes at 266˚F (130˚C).
TOP HEATING ELEMENT
The top heating element is located at the top of the oven cavity. It
is intended to heat air driven by the convection fan.
11
R-8000G
Hot air
Hot air
Hot air
Convection
fan
Hot air
Oven cavity left side
Oven cavity
top wall
Side heating
element unit
Side heating
element unit
Top heating element unit
Top heating element unit
Turntable
Convection Mode JET Mode
The heated air is kept in the oven and force-circulated and
reheated by the top heating element.
SIDE HEATING ELEMENT
The side heating element is located at the left side of the oven
cavity. It is intended to heat air driven by the convection fan. The
heated air is kept in the oven and force-circulated and reheated by
the top heating element.
TURNTABLE MOTOR
The turntable motor rotates the turntable located in the bottom of
the oven cavity, so that the food on the turntable is cooked evenly
during cooking. The turntable may turn in either direction.
FAN MOTOR (MAGNETRON SIDE)
The fan motor drives a blade which draws external cool air. This
cool air is directed through the air vents surrounding the magnetron
and cools the magnetron. This air is channelled through the oven
cavity to remove steam and vapors given off from the heating
foods. It is then exhausted through the exhausting air vents at the
oven cavity.
FAN MOTOR (POWER TRANSFORMER SIDE)
The fan motor drives a blade which draws external cool air. This
cool air is directed through the air vents surrounding the power
transformer and cools the power transformer. This air is channelled through the oven cavity to remove steam and vapors given
off from the heating foods. It is then exhausted through the
exhausting air vents at the oven cavity.
Top heating
element unit
Side heating
element unit
Convection
fan
Convection mode
FRONT VIEW
JET
mode
Figure D-2. Rotation direction of convection fan
CONVECTION COOKING SYSTEM
This oven is designed with a hot air heating system where food is not
directly heated by the heating element, but is heated by forced
circulation of the hot air produced by the heating elements. The air
heated by the heating elements is circulated through the convection
passage provided on the outer casing of the oven cavity by means
of the convection fan which is driven by the jet motor. It then enters
the inside of the oven through the vent holes provided on the top and
left sides of the oven. Next, the hot air heats the food on the turntable
and leaves the oven cavity through the vent in the center of the oven
cavity back side wall. Without leaving the oven, this hot air is
reheated by the heating elements, passes through the convection
passage and enters the inside of the oven cavity again, in a
continuing cycle. In this way, the hot air circulates inside the oven
cavity to raise its temperature and, at the same time, comes into
contact with the food being cooked. When the temperature inside the
oven cavity reaches the selected temperature, the heating elements
are de-energized. When the temperature inside the oven cavity
drops below the selected temperature, the heating elements are
energized again. In this way, the inside of the oven cavity is
maintained at approximately the selected temperature. When the
convection time reaches 0, the heating elements are de-energized
and the convection fan stops operating and the oven shuts off.
Flow of hot air:
The rotation direction of the jet motor is controlled by relay RY6.
When the convection fan rotates clockwise, the hot air from the
oven cavity left side wall blows stronger than one from the oven
cavity top wall. ( This mode is called “Convection mode”.) When the
convection fan rotates counterclockwise, the hot air from the oven
cavity top wall blows stronger than one from the oven cavity left
side wall. (This mode is called “JET mode”.)
Figure D-3. Flow of hot air
12
R-8000G
TROUBLESHOOTING GUIDE
Never touch any part in the circuit with your hand or an uninsulated tool while the power supply is connected.
When troubleshooting the microwave oven, it is helpful to follow the Sequence of Operation in performing the checks. Many
of the possible causes of trouble will require that a specific test be performed. These tests are given a procedure letter which
will be found in the "Test Procedure "section.
IMPORTANT: If the oven becomes inoperative because of a blown monitor fuse, check the monitor switch, relay (RY1) primary interlock
relay (RY2), door sensing switch and secondary interlock switch before replacing the monitor fuse. If the monitor fuse
is replaced, the monitor switch must also be replaced. Use part FFS-BA033WRKZ 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
2. Remove the outer case cabinet, referring to "OUTER CASE CABINET REMOVAL".
3. Open the door and block it open.
4. Discharge high voltage capacitor.
5. Remove the back plate from the oven, referring to "BACK PLATE REMOVAL".
6. Disconnect the leads to the primary of the power transformer.
7. Ensure that the leads remain isolated from other components and oven chassis by using insulation tape.
8. After that procedure, reconnect the power supply cord.
When the testing is completed
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Reconnect all leads removed from components during testing.
5. Reinstall the outer case (cabinet) and theback plate.
6. Reconnect the power supply cord after the outer case and the back plate are installed.
7. Run the oven and check all functions.
13
R-8000G
TEST PROCEDURE
POSSIBLE CASE AND
DEFECTIVE PARTS
CONDITION OFF CONDITION COOKING CONDITION MICROWAVE COOKING ERROR MODE
ABCDEEFGHJKMOSTUVVVVVXYWW
RE: Replace / CK: Check
RE RERE RERECK CKCKCK CK
PLNUIP
PROBLEM
Home fuse blows when power cord
is plugged into wall receptacle.
Monitor fuse blows when power
cord is plugged into wall receptacle
does not appear in display
when power cord is first plugged
into wall receptacle.
Oven lamp does not light with door
opened.
Oven lamp does not light in cook
cycle. (It light when door is
opened).
Oven lamp light, but turntable motor does not operate.
Tu r ntable motor operates normally
but cooling fan motor does not operate.
Oven does not go into a cook cycle, when START pad is touched.
Low or no power is produced during microwave cooking (The food is
heated incompletely or not heated
at all)
Extremely uneven heating is produced in oven load (food).
Function of variable cooking does
not operate properly except 100%
power.
Function of EXPRESS DEFROST
does not operate properly.
EXCEPT FOR
MICROWAVE
Heating elements do not heat.
COOKING
Temperature in the oven cavity is
lower or higher than preset.
Jet motor does not operate at all or
properly.
Oven operates for 10 minutes then
shuts down, and "THERMISTOR
FAILURE" appears.
"MEMORY FAILURE" appears.
"MAXIMUM TIME EXCEEDED" ap-
pears.
"CHECK 1" appears. (Total opera-
tion time (hours) of magnetron exceeds 1250 hours.)
"CHECK 2" appears. (Total operation time (hours) of top heating element exceeds 4000 hours.)
"CHECK 3" appears. (Total operation time (hours) of side heating
element exceeds 4000 hours.)
MAGNETRON
POWER TRANSFORMER
H.V. RECTIFIER ASSEMBLY
HIGH VOLTAGE CAPACITOR
SECONDARY INTERLOCK SWITCH
3RD. LATCH SWITCH
PRIMARY INTERLOCK SYSTEM
MONITOR SWITCH
MONITOR FUSE 20A
MAGNETRON TEMPERATURE FUSE
THERMAL CUT-OUT (TOP)
TOP HEATING ELEMENT
THERMISTOR
NOISE FILTER
TOUCH CONTROL PANEL
TACT SWITCH
RELAY RY-1
RELAY RY-2
RELAY RY-3
RELAY RY-5
RELAY RY-6
EXPRESS DEFROST
FUSE1 ON PWB.
SOLID-STATE RELAY (TOP)
SOLID-STATE RELAY (SIDE)
OVEN LAMP
FAN MOTOR (MAGNETRON)
TURNTABLE MOTOR
JET MOTOR
LOOSE WIRING
SHORTED IN POWER CORD
NO POWER AT OUTLET
LOW VOLTAGE
THERMAL CUT OUT (SIDE)
SIDE HEATING ELEMENT
FAN MOTOR (POWER TRANSFORMER)
T/C TRANSFORMER
FUSE F10A
JET MOTOR CAPACITOR
WRONG OPERATION
MISADUSTMENT SWITCH
14
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