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 the 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
GENERAL INFORMATION...................................................................................................................................4
TEST PROCEDURE ............................................................................................................................................11
TOUCH CONTROL PANEL ASSEMBLY ............................................................................................................18
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ................................................................23
POWER UNIT CIRCUIT ......................................................................................................................................31
LSI UNIT CIRCUIT...............................................................................................................................................32
PARTS LIST ........................................................................................................................................................34
PACKING AND ACCESSORIES .........................................................................................................................38
SHARP CORPORATION
This document has been published to be used for after
sales service only.
The contents are subject to change without notice.
39
Page 2
R-1200
R-1201
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.
40
Page 3
W ARNING TO SER VICE PERSONNEL
Microwave ovens contain circuitry capable of producing very high voltage and current, contact with
following parts
fatal, electrical shock.
(Example)
High Voltage Capacitor, High Voltage Power Trans-
former, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..
Read the Service Manual carefully and follow all
instructions.
may result in a severe, possibly
Don't Touch !
Danger High Voltage
R-1200
R-1201
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 highvoltage capacitor (that is the connecting lead of the highvoltage 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 these 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 reexamine the connections to the component being tested.
When all service work is completed and the oven is fully
assembled, the microwave power output should be checked
and microwave leakage test should be carried out.
1
Page 4
R-1200
R-1201
MICROW A VE 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 switch shall prevent microwave radiation emission in excess of the
requirement as above mentioned, secondary interlock relay and door sensing 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 primary interlock switch does turn the oven OFF before any door movement.
NOTE: After servicing, record data on service invoice and microwave leakage report.
2
Page 5
SERVICE MANUAL
R-1200
R-1201
OVER THE COUNTER
MICROWAVE OVEN
R-1200/ R-1201
FOREWORD
This Manual has been prepared to provide Sharp Electronics Corp.
Service Personnel with Operation and Service Information for the
SHARP OVER THE COUNTER MICROWAVE OVEN, R-1200 and
R-1201.
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 not any other visible damage with the oven.
PRODUCT DESCRIPTION
GENERAL INFORMATION
OPERATION
TROUBLESHOOTING GUIDE AND
TEST PROCEDURE
TOUCH CONTROL PANEL
COMPONENT REPLACEMENT
AND ADJUSTMENT PROCEDURE
WIRING DIAGRAM
Servicing and repair work must be carried out only by trained
service personnel.
DANGER
Certain initial parts are intentionally not grounded and present
a risk of electrical shock only during servicing. Service
personnel - Do not contact the following parts while the
appliance is energized;
High Voltage Capacitor, Power Transformer, Magnetron, High
Voltage Rectifier Assembly, High Voltage Harness;
If provided, Vent Hood, Fan assembly, Cooling Fan Motor.
All the parts marked “*” on parts list are used at voltages more than
250V.
Removal of the outer wrap gives access to voltage above 250V.
All the parts marked “∆” on parts list may cause undue microwave
exposure, by themselves, or when they are damaged, loosened
or removed.
SHARP ELECTRONICS CORPORATION
SHARP PLAZA, MAHWAH,
NEW JERSEY 07430-2135
PARTS LIST
3
Page 6
R-1200
R-1201
PRODUCT SPECIFICA TION
ITEMDESCRIPTION
Power Requirements120 Volts / 14.1 Amperes
60 Hertz
Single phase, 3 wire grounded
Power Output1100 watts (IEC TEST PROCEDURE)
Operating frequency of 2450MHz
Case DimensionsWidth23-7/8"
Height14-1/16"
Depth 15- 9/16"
Cooking Cavity DimensionsWidth17-1/2"
Height9-7/8"
1.5 Cubic FeetDepth 14-15/16"
Hood lamp2 bulbs, 20W x 2, Incandescent light bulbs
Control ComplementTouch Control System
Microwave Power for Variable Cooking
Repetition Rate;
P-HI..................................................Full power throughout the cooking time
P-90 .................................................................... approx. 90% of Full Power
P-80 .................................................................... approx. 80% of Full Power
P-70 .................................................................... approx. 70% of Full Power
P-60 .................................................................... approx. 60% of Full Power
P-50 .................................................................... approx. 50% of Full Power
P-40 .................................................................... approx. 40% of Full Power
P-30 .................................................................... approx. 30% of Full Power
P-20 .................................................................... approx. 20% of Full Power
P-10 .................................................................... approx. 10% of Full Power
P-0 .................................................... No power throughout the cooking time
KEEP WARM pad, ACCENT LIGHT pad
TASK LIGHT pad, REHEAT CENTER pads
COOK CENTER pads, DEFROST CENTER pads
Number selection pads, POWER LEVEL pad
TIMER / CLOCK pad, MINUTE PLUS pad
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.
4
Page 7
R-1200
R-1201
Electrical Requirements
The oven is equipped with a 3-prong grounding plug. DO NOT UNDER ANY CIRCUMSTANCES CUT OR REMOVE THE
GROUNDING PIN FROM THE PLUG.
The power supply cord and plug must be connected to a separate 120 Volt AC, 60 Hz, 15 Amp. or more dedicated line, using
a grounded receptacle. The receptacle should be located inside the cabinet directly above the Microwave Oven/Hood
system mounting location.
3-Pronged Plug
Grounded
Receptacle Box
Grounding Pin
3-Pronged Receptacle
OVEN DIAGRAM
1
15
2
5
6
4
9
3
8
7
7
1. Oven door with see-through window.
2. Door hinges.
3. Waveguide cover.
4. Turntable motor shaft.
5. Oven lamp.
It will light when oven is operating or door is open.
6. Door latches.
The oven will not operate unless the door is
securely closed.
7. One touch door open button.
8. Auto Touch control panel
9. Time display: Digital display, 99 minutes 99
seconds.
10
13
12
11
14
10.Ventilation openings.
10
11.Light Cover.
12.Bottom sash.
13.Removable turntable.
The turntable will rotate clockwise or
counterclockwise.
Only remove for cleaning.
14.Removable turntable support.
15. Power supply cord
CONTROL PANEL
TIMER
CLOCK
ACCENT
LIGHT
KEEP
WARM
TASK
LIGHT
BAKED
POTATOES
FROZEN
VEGETABLES
NOTE: Some one-touch cooking features such as "MINUTE PLUS" are disabled after three minutes when the oven is not
used. These features are automatically enabled when the door is opened and closed or STOP/CLEAR button is
pressed.
COOK CENTER
RICE
FRESH
VEGETABLES
GROUND
MEAT
FROZEN
ENTREES
POPCORN
HOT
WATER
REHEAT
CENTER
DEFROST
CENTER
COOK DEFROST
1100
WATTS
5
MINUTE
NO.
LBS.
CUPS
OZ.
12345
67890
POWER
LEVEL
STOP
CLEAR
PLUS
START
Page 8
R-1200
R-1201
OPERATION
DESCRIPTION OF OPERATING SEQUENCE
The following is a description of component functions during
oven operation.
OFF CONDITION
Closing the door activates the door sensing switch and
primary interlock switch. (In this condition, the monitor
switch contacts are opened.)
When oven is plugged in, 120 volts A.C. is supplied to the
control unit. (Figure O-1).
1. The display will show flashing "88 : 88".
To set any program or set the clock, you must first
touch the STOP/CLEAR pad. The display will clear,
and " : " will appear .
COOKING CONDITION
Program desired cooking time touching the NUMBER pads.
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)
RELAYCONNECTED COMPONENTS
RY1Oven lamp / Fan motor / Turntable motor
RY2Power transformer
RY3, RY4 Hood lamp
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.
6. When the door is opened during a cook cycle, monitor
switch, door sensing switch, primary interlock switch,
relay (RY1) and secondary interlock relay (RY2) are
activated with the following results. The circuits to the
cooling fan motor, the turntable 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 switch and secondary interlock
relay (RY2) 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
secondary interlock relay (RY2) and primary 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 first open, and then the
contacts of the primary interlock switch and door
sensing switch close. And contacts of the relay
(RY1) open.
If the primary interlock switch and secondary interlock relay
(RY2) 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, primary interlock
switch, relay (RY1) and secondary interlock relay (RY2),
causing the monitor fuse to blow.
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 (RY2) which is operated by the
control unit within an interval second time base. Microwave
power operation is as follows:
VARI-MODEON TIMEOFF TIME
Power 10(P-HI)32 sec.0 sec.
(100% power)
Power 9(P-90)30 sec.2 sec.
(approx. 90% power)
Power 8(P-80)26 sec.6 sec.
(approx. 80% power)
Power 7(P-70)24 sec.8 sec.
(approx. 70% power)
Power 6(P-60)22 sec.10 sec.
(approx. 60% power)
Power 5(P-50)18 sec.14 sec.
(approx. 50% power)
Power 4(P-40)16 sec.16 sec.
(approx. 40% power)
Power 3(P-30)12 sec.20 sec.
(approx. 30% power)
Power 2(P-20) 8 sec.24 sec.
(approx. 20% power)
Power 1(P-10) 6 sec.26 sec.
(approx. 10% power)
Power 0(P-0) 0 sec.32 sec.
(0% power)
Note: The ON/OFF time ratio does not correspond with
the percentage of microwave power, because
approx. 3 seconds are needed for heating of the
magnetron filament.
6
Page 9
NOTE: " " indicates components with potential above 250V.
MAGNETRON
TEMPERATURE FUSE
FUSE
20A
TURNTABLE
MOTOR
FAN
MOTOR
MAGNETRON
OVEN LAMP
MONITOR
SWITCH
BLKWHT
POWER
TRANSFORMER
HIGH VOLTAGE
CAPACITOR
1.0µF/ AC2300V
HIGH VOLTAGE
RECTIFIER
COM.
N.O.
COM.
CONTROL UNIT
GND
GRN
A1
A3A5
N.O.
B2
B1
DOOR
SENSING
SWITCH
PRIMARY
INTERLOCK
SWITCH
120 V AC.
60 Hz
HOOD
LAMP
HL
RY1
RY2
SECONDARY
INTERLOCK
RELAY
OVEN LAMP
RELAY
FM
OL
TTM
RY3
RY4
CAVITY
TEMPERATURE FUSE
HL
TURNTABLE
MOTOR
FAN
MOTOR
MAGNETRON
OVEN LAMP
MONITOR
SWITCH
POWER
TRANSFORMER
HIGH VOLTAGE
RECTIFIER
COM.
N.O.
COM.
CONTROL UNIT
N.O.
B2
B1
DOOR
SENSING
SWITCH
PRIMARY
INTERLOCK
SWITCH
RY1
RY2
SECONDARY
INTERLOCK
RELAY
OVEN LAMP
RELAY
FM
OL
TTM
MAGNETRON
TEMPERATURE FUSE
FUSE
20A
BLKWHT
HIGH VOLTAGE
CAPACITOR
1.0µF/ AC2300V
GND
GRN
A1
A3A5
120 V AC.
60 Hz
HOOD
LAMP
HL
RY3
RY4
CAVITY
TEMPERATURE FUSE
HL
R-1200
R-1201
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. CLOCK APPEARS ON DISPLAY.
Figure O-1. Oven Schematic-Off Condition
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. COOKING TIME PROGRAMMED.
3. VARIABLE COOKING CONTROL "HIGH".
4. "START" BUTTON PRESSED.
Figure O-2. Oven Schematic-Cooking Condition
7
Page 10
R-1200
R-1201
DESCRIPTION AND FUNCTION OF COMPONENTS
DOOR OPEN MECHANISM
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 open lever, and then the open lever pushes up the latch
head. The latch heads are moved upward and released
from latch hook. Now the door will open.
Latch heads
Latch hook
Door sensing
Door
Open lever
switch
Monitor switch
Primary interlock switch
Figure D-1. Door Open Mechanism
DOOR SENSING AND PRIMARY INTERLOCK
SWITCHES
The primary interlock switch is mounted in the lower position of the latch hook and the door sensing switch in the
secondary 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 circuit to all components. A cook cycle cannot take
place until the door is firmly closed thereby activating both
interlock switches. The secondary interlock system consists of the door sensing switch and secondary interlock
relay located on the control circuit board.
MONITOR SWITCH
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 secondary interlock relay (RY2) and primary 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 secondary interlock relay (RY2)
and primary interlock switch are in the OFF condition
(contacts open) due to their being normally open contact
switches. And the contacts of relay (RY1) are in the ON
condition (contacts close).
2. As the door goes to a closed position, the monitor switch
contacts are first opened and then the door sensing
switch and the primary interlock switch contacts close.
(On opening the door, each of these switches operate
inversely.)
3. If the door is opened, and the secondary interlock relay
(RY2) and primary 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,
SECONDARY INTERLOCK RELAY (RY2),
RELAY (RY1), PRIMARY INTERLOCK
SWITCH AND MONITOR SWITCH FOR
PROPER OPERATION. (REFER TO CHAPTER "TEST PROCEDURE").
NOTE: MONITOR FUSE AND SWITCH ARE REPLACED
AS AN ASSEMBLY
TEMPERATURE FUSE (MG)
The temperature fuse located on the fan duct assembly is
designed to prevent damage to the magnetron if an over
heated condition develops in the tube due to cooling fan
failure, obstructed air guide, dirty or blocked air intake, etc.
Under normal operation, the temperature fuse remains
closed. However, the temperature fuse will open at 302˚F
(150˚C) causing the oven to shut down.
NOTE: This is a fuse. It does not reset.
TEMPERATURE FUSE (CAVITY )
This temperature fuse is located on the top of the oven
cavity. It is designed to prevent damage to the oven unit if
the food in the oven catches fire due to overheating produced by improper setting of cooking time or failure of
control unit.
Under normal operation, the temperature fuse remains
closed. However, the temperature fuse will open at 302˚F
(150˚C) causing the oven to shut down. The defective
temperature fuse must be replaced with a new one.
TURNTABLE MOTOR
The turntable motor rotates the turntable located on the
bottom of the oven cavity, so that the foods on the turntable
cook evenly during cooking. Turntable will turn in either
direction. The turntable motor can be turned off by touching
TURNTABLE ON/OFF pad.
COOLING FAN MOTOR
The cooling fan motor drives a blade which draws external
cool air. This cool air is directed through the air vanes
surrounding the magnetron and cools the magnetron. This air
is channelled through the oven cavity to remove steam and
vapors given off from the heating foods. It is then exhausted
through the exhausting air vents at the oven cavity.
HOOD LAMP
The hood lamps are mounted at the hood lamp angle on
the base cover. The hood lamps can be turned off and on
by touching the ACCENT LIGHT pad or TASK LIGHT pad.
And also the brightness can be varied to high or low by
touching the ACCENT LIGHT pad or TASK LIGHT pad.
8
Page 11
R-1200
R-1201
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)
secondary interlock relay (RY2), door sensing switch and primary interlock switch before replacing the
monitor fuse. If monitor fuse is replaced, the monitor switch must also be replaced. Use part FFS-BA016/
KiT 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.
9
Page 12
R-1200
R-1201
CK = Check / RE = Replace
CONDITION
OFF
CONDITION
IDLE
CONDITION
MICROWAVE
COOKING
CONDITION
TEST PROCEDURE
POSSIBLE CASE AND
DEFECTIVE PARTS
PROBLEM
Home fuse blows when power cord
is plugged into wall receptacle.
Monitor fuse blows when power cord
is plugged into wall receptacle.
Display does not illuminate when
power cord is first plugged into wall
receptacle.
Display does not operate properly
when STOP/CLEAR pad is touched.
(The time of day should appear on
the display with beep sound during
normal condition.)
Oven lamp does not light with door is
opened.
Hood lights do not turn on when
ACCENT LIGHT pad or TASK
LIGHT pad is pressed.
Oven lamp does not light in cook
cycle. (But it does light when door is
opened.)
Fan motor does not operate. (Oven
lamp and turntable motor operate.)
Turntable motor does not operate
(Oven lamp lights and fan motor
operate.)
Oven does not go into cook cycle
when START pad is touched.
Oven seems to be operating but little
or no heat is produced in oven load.
(Food incompletely cooked or not
cooked at all at end of cook cycle.)
Oven goes into a cook cycle but
extremely uneven heating is
produced in oven load (food).
Variable cooking does not operate
properly except Cooking Power 10
(P-HI) mode.
Oven goes into DEFROST CENTER
but food is not defrosted well.
ABCDEFGHIJKLLLLMNRE RERE RECK RECK CK
MAGNETRON
POWER TRANSFORMER
H.V. RECTIFIER
HIGH VOLTAGE CAPACITOR
TEMPERATURE FUSE
PRIMARY INTERLOCK SWITCH
SECONDARY INTERLOCK SYSTEM
MONITOR SWITCH
MONITOR FUSE
CONTROL UNIT
KEY UNIT
RELAY (RY-1)
RELAY (RY-2)
RELAY (RY-3)
RELAY (RY-4)
DEFROST CENTER
FOIL PATERN ON P.W.B.
OVEN LAMP OR SOCKET
FAN MOTOR
TURNTABLE MOTOR
HOOD LAMP OR SOCKET
OPENED OR SHORTED WIRING
SHORT IN POWER CORD
NO POWER AT OUTLET
LOW VOLTAGE
10
Page 13
TEST PROCEDURES
R-1200
R-1201
PROCEDURE
LETTER
AMAGNETRON ASSEMBLY TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. To test for an open filament, isolate the magnetron from the high voltage circuit. A continuity check
across the magnetron filament leads should indicate less than 1 ohm.
5. To test for a shorted magnetron, connect the ohmmeter leads between the magnetron filament leads
and chassis ground. This test should indicate an infinite resistance. If there is little or no resistance
the magnetron is grounded and must be replaced.
6. Reconnect all leads removed from components during testing.
7. Reinstall the outer case (cabinet).
8. Reconnect the power supply cord after the outer case is installed.
9. Run the oven and check all functions.
MICROWAVE OUTPUT POWER
The following test procedure should be carried out with the microwave oven in a fully assembled
condition (outer case fitted).
HIGH VOLTAGES ARE PRESENT DURING THE COOK CYCLE, SO EXTREME CAUTION SHOULD
BE OBSERVED.
Power output of the magnetron can be measured by performing a water temperature rise test. This test
should only be used if above tests do not indicate a faulty magnetron and there is no defect in the following
components or wiring: silicon rectifier, high voltage capacitor and power transformer. This test will require
a 16 ounce (453cc) measuring cup and an accurate mercury thermometer or thermocouple type
temperature tester. For accurate results, the following procedure must be followed carefully:
1. Fill the measuring cup with 16 oz. (453cc) of tap water and measure the temperature of the water with
a thermometer or thermocouple temperature tester. Stir the thermometer or thermocouple through
the water until the temperature stabilizes. Record the temperature of the water.
2. Place the cup of water in the oven. Operate oven at POWER 10(HIGH) 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 32
to 60˚F(18 to 33˚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.
COMPONENT TEST
BPOWER TRANSFORMER TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the 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 83 ohms; the resistance of the filament coil should be less than 1 ohm.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
11
Page 14
R-1200
R-1201
TEST PROCEDURES
PROCEDURE
LETTER
(HIGH VOLTAGES ARE PRESENT AT THE HIGH VOLTAGE TERMINAL, SO DO NOT ATTEMPT TO
MEASURE THE FILAMENT AND HIGH VOLTAGE.)
CHIGH VOLTAGE RECTIFIER TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Isolate the rectifier from the circuit. Using the highest ohm scale of the meter, read the resistance
across the terminals and observe, reverse the leads to the rectifier terminals and observe meter
reading. If a short is indicated in both directions, or if an infinite resistance is read in both directions,
the rectifier is probably defective and should be replaced.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
NOTE: Be sure to use an ohmmeter that will supply a forward bias voltage of more than 6.3 volts.
DHIGH VOLTAGE CAPACITOR TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. If the capacitor is open, no high voltage will be available to the magnetron. Disconnect input leads
and check for short or open between the terminals using an ohmmeter.
Checking with a high ohm scale, if the high voltage capacitor is normal, the meter will indicate
continuity for a short time and should indicate an open circuit once the capacitor is charged. If the
above is not the case, check the capacitor with an ohmmeter to see if it is shorted between either of
the terminals and case. If it is shorted, replace the capacitor.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
COMPONENT TEST
ECAVITY TEMPERATURE FUSE TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. A continuity check across the temperature fuse terminals should indicate a closed circuit unless the
temperature of the temperature fuse reaches approximately 302˚F(150˚C).
An open temperature fuse indicates overheating of the oven, exchange the temperature fuse and
check inside of oven cavity and for improper setting of cooking time or operation of control unit. Check
for restricted air flow through the vent holes of the oven cavity, especially the cooling fan and air guide.
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.
MAGNETRON TEMPERATURE FUSE TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. A continuity check across the temperature fuse terminals should indicate a closed circuit. If the
temperature of the magnetron reaches approximately 302˚F(150˚C), the temperature fuse opens. An
open temperature fuse indicates overheating of the magnetron. Exchange the temperature fue and
check for restricted air flow to the magnetron, especially the cooling fan air guide.
5. Reconnect all leads removed from components during testing.
12
Page 15
TEST PROCEDURES
R-1200
R-1201
PROCEDURE
LETTER
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
CAUTION: IF THE TEMPERATURE FUSE INDICATES AN OPEN CIRCUIT AT ROOM TEMPERA-
TURE, REPLACE TEMPERATURE FUSE.
FPRIMARY INTERLOCK SWITCH TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal
of the switch. The meter should indicate an open circuit with the door open and a closed circuit with
the door closed. If improper operation is indicated, replace the secondary interlock switch.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
GSECONDARY INTERLOCK SYSTEM TEST
DOOR SENSING SWITCH
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal
of the switch. The meter should indicate an open circuit with the door open and a closed circuit with
the door closed. If improper operation is indicated, replace the door sensing switch.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
NOTE: If the door sensing switch contacts fail in the open position and the door is closed, the cooling
fan motor, stirrer motor and oven light will be activated by RY1.
COMPONENT TEST
SECONDARY INTERLOCK RELAY (RY2)
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect two (2) wire leads from the male tab terminals of the Secondary Interlock Relay. Check
the state of the relay contacts using a ohmmeter. The relay contacts should be open. If the relay
contacts are closed, replace the circuit board entirely or the relay itself.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
HMONITOR SWITCH TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Before performing this test, make sure that the primary interlock switch and the secondary interlock
relay are operating properly, according to the above Switch and Interlock system Test Procedures.
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.
13
Page 16
R-1200
R-1201
TEST PROCEDURES
PROCEDURE
LETTER
IBLOWN MONITOR FUSE TEST
COMPONENT TEST
When the monitor switch actuator is pushed by a screw driver through the lower latch hole on the front
plate of the oven cavity with the door opened (in this condition the plunger of the monitor switch is
pushed in), the meter should indicate an open circuit. If improper operation is indicated, the switch
may be defective. After testing the monitor switch, reconnect the wire lead to the monitor switch
(COM) terminal and check the
continuity of the monitor circuit.
Red
White/ White
5. Reconnect all leads removed from
components during testing.
6. Reinstall the outer case (cabinet).
Screw Driver
7. Reconnect the power supply cord
after the outer case is installed.
8. Run the oven and check all
functions.
Primary
Interlock Switch
Monitor Switch
Ohmmeter
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. If the monitor fuse is blown when the door is opened, check the secondary interlock relay, primary
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 SECONDARY INTER-
LOCK RELAY, PRIMARY INTERLOCK SWITCH, DOOR SENSING SWITCH AND MONI-
TOR 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-BA016/KiT, even if
the monitor switch operates normally. The monitor fuse and monitor switch assembly is comprised
of a 20 ampere fuse and switch.
5. Reconnect all leads removed from components during testing.
6. Re-install the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
JTOUCH CONTROL PANEL ASSEMBLY TEST
The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore,
unlike conventional microwave ovens, proper maintenance cannot be performed with only a voltmeter
and ohmmeter.
In this service manual, the touch control panel assembly is divided into two units, Control Unit and Key
Unit, and also the Control Unit is divided into two units, LSI Unit and Power Unit, and troubleshooting by
unit replacement is described according to the symptoms indicated.
Before testing,
1) Disconnect the power supply cord, and then remove outer case. Refer to procedure of "
REMOVAL OF OVEN FROM WALL " and " OUTER CASE REMOVAL ".
2) Open the door and block it open.
3) To discharge high voltage capacitor, wait for 60 seconds.
4) Disconnect the leads to the primary of the power transformer.
5) Ensure that these leads remain isolated from other components and oven chassis by using insulation
tape.
1. Key Unit.
NOTE ;
1) Check key unit ribbon connection before replacement.
2) Re-install the outer case (cabinet).
3) Reconnect the power supply cord after the outer case is installed.
4) Run the oven and check all functions.
14
Page 17
TEST PROCEDURES
R-1200
R-1201
PROCEDURE
LETTER
COMPONENT TEST
The following symptoms indicate a defective key unit.
a) When touching the pads, a certain pad produces no signal at all.
b) When touching a number pad, two figures or more are displayed.
c) When touching the pads, sometimes a pad produces no signal.
If the key unit is defective, replace the key unit.
2. Control Unit.
The following symptoms indicate a defective control unit. Before replacing the control unit, perform
the Key unit test (Procedure K) to determine if control unit is faulty.
2-1 In connection with pads.
a) When touching the pads, a certain group of pads do not produce a signal.
b) When touching the pads, no pads produce a signal.
2-2 In connection with indicators
a) At a certain digit, all or some segments do not light up.
b) At a certain digit, brightness is low.
c) Only one indicator does not light.
d) The corresponding segments of all digits do not light up; or they continue to light up.
e) Wrong figure appears.
f) A certain group of indicators do not light up.
g) The figure of all digits flicker.
2-3 Other possible problems caused by defective control unit.
a) Buzzer does not sound or continues to sound.
b) Clock does not operate properly.
c) Cooking is not possible.
When testing is completed,
1) Disconnect the power supply cord.
2) Open the door and block it open.
3) To discharge high voltage capacitor, wait for 60 seconds.
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.
KKEY UNIT TEST
1. Disconnect the power supply cord.
2. Open the door and block it open.
3. To discharge high voltage capacitor, wait for 60 seconds.
4. If the display fails to clear when the STOP/CLEAR pad is depressed, first verify the flat ribbon cable
is making good contact, verify that the door sensing switch operates properly; that is the contacts are
closed when the door is closed and open when the door is open. If the door sensing switch is good,
disconnect the flat ribbon cable that connects the key unit to the control unit and make sure the door
sensing switch is closed (either close the door or short the door sensing switch connecter). Use the
Key unit matrix indicated on the control panel schematic and place a jumper wire between the pins
that correspond to the STOP/CLEAR pad making momentary contact. If the control unit responds by
clearing with a beep the key unit is faulty and must be replaced. If the control unit does not respond,
it is faulty and must be replaced. If a specific pad does not respond, the above method may be used
(after clearing the control unit) to determine if the control unit or key pad is at fault.
5. Reconnect all leads removed from components during testing.
6. Re-install the outer case cabinet.
7. Reconnect the power supply cord.
8. Run the oven and check all functions.
15
Page 18
R-1200
R-1201
TEST PROCEDURES
PROCEDURE
LETTER
LRELAY TEST
COMPONENT TEST
G10
FROZEN
VEGETABLES
G11G12G 9
BAKED
POTATOES
G 8
5
0
G 7G 6G 5G 4G 3G 2G 1
4
9
FRESH
VEGETABLES
RICE
3
8
FROZEN
ENTREES
GROUND
MEAT
2
7
HOT
WATER
POPCORN
1
6
DEFROST
CENTER
REHEAT
CENTER
POWER
LEVEL
STOP
CLEAR
TASK
LIGHT
KEEP
WARM
MINUTE
PLUS
START
ACCENT
LIGHT
TIMER
CLOCK
1. Disconnect the power supply cord, and then remove outer case. Refer to procedure of " REMOVAL
OF OVEN FROM WALL " and " OUTER CASE REMOVAL ".
2. Open the door and block it open.
3. To discharge high voltage capacitor, wait for 60 seconds.
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. Check voltage between normal open terminal of the relay RY2 and the normal open terminal of the
relay RY1 on the control unit with an A.C. voltmeter.
The meter should indicate 120 volts, if not check oven circuit.
RY1, RY2, RY3 and RY4 Relay Test
These relays are operated by D.C. voltage
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation.
DC. voltage indicated ....................Defective relay.
DC. voltage not indicated .............. Check diode which is connected to the relay coil. If diode is
RY1Approx. -27.9V D.C.Oven lamp / Fan motor / Turntable motor
RY2(COOK)Approx. -26.9V D.C.Power transformer
RY3Approx. -27.9V D.C.Hood lamp
RY4Approx. -27.9V D.C.Hood lamp
8. Disconnect the power supply cord.
9. Open the door and block it open.
10. To discharge high voltage capacitor, wait for 60 seconds.
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.
MDEFROST CENTER TEST
(1) Open the door.
(2) Place one cup of water in the center of the turntable tray in the oven cavity.
(3) Close the door.
(4) Touch the " DEFROST CENTER " pad. And touch the number pad 2. Then touch the number pad
5.
(5) Touch the " START " pad.
(6) The oven is in Defrost center cooking condition.
(7) The oven will operate as follows.
16
Page 19
TEST PROCEDURES
RY1
RY2
(J1)
b
c
d
a
T1
13
VRS1
R-1200
R-1201
PROCEDURE
LETTER
COMPONENT TEST
Menu1ST STAGE2ND STAGE
Steaks/Chops LEVELTIMELEVELTIME
0.5lbs60%57sec.40%17sec.
(8) If improper operation is indicated, the control unit is probably defective and should be checked.
NFOIL 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.
2) Open the door and block it open.
3) To discharge high voltage capacitor, wait for 60 seconds.
4) Remove the power unit, referring to the procedure of " RIGHT PANEL ASSEMBLY AND POWER
UNIT REMOVAL ".
5) Follow the troubleshooting guide given below for repair.
STEPSOCCURRENCECAUSE OR CORRECTION
1Only pattern at "a" is broken.*Insert jumper wire J1 and solder.
2Pattern at "a" and "b" are broken.*Insert the coil RCILF2003YAZZ between "c" and "d".
6) 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 780Ω ± 10%). If any
abnormal condition is detected, replace
the defective parts.
7) Reconnect all leads removed from components during testing.
8) Re-install the power unit to the right panel and re-install the right panel to the oven.
9) Reconnect the power supply cord.
10) 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. Refer to procedure of "
REMOVAL OF OVEN FROM WALL " and " OUTER CASE REMOVAL ".
2) Open the door and block it open.
3) To discharge high voltage capacitor, wait for 60 seconds.
4) Disconnect the leads to the primary of the power transformer.
5) Ensure that these leads remain isolated from other components and oven chassis by using
insulation tape.
6) After that procedure, re-connect the power supply cord.
7) Follow the troubleshooting guide given below for repair.
STEPSOCCURRENCECAUSE OR CORRECTION
The rated AC voltage is not present between
1the normal open terminal of the relay RY2 and Check supply voltage and oven power cord.
the normal open terminal of the relay RY1.
The rated AC voltage is present at primaryLow voltage transformer or secondary circuit defective.
2
side of low voltage transformer.Check and repair.
17
Page 20
R-1200
R-1201
TEST PROCEDURES
PROCEDURE
LETTER
8) Disconnect the power supply cord.
9) Open the door and block it open.
10) To discharge high voltage capacitor, wait for 60 seconds.
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.
TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOUCH CONTROL PANEL
The touch control section consists of the following units
as shown in the touch control panel circuit.
COMPONENT TEST
SymbolVoltageApplication
VC-5.3VLSI(IC1)
(1) Key Unit
(2) Control Unit (The Control unit consists of LSI Unit and
Power Unit)
The principal functions of these units and the signals communicated among them are explained below.
Key Unit
The key unit is composed of a matrix, signals generated in
the LSI are sent to the key unit through P20, P21, P22, P23,
P24, P25, P26 and P27.
When a key pad is touched, a signal is completed through
the key unit and passed back to the LSI through P43, P44,
P45 and P46 to perform the function that was requested.
Control Unit
Control unit consists of LSI, power source circuit, synchronizing signal circuit, reset circuit, buzzer circuit, relay circuit
indicator circuit and back light circuit.
1) LSI
This LSI controls the key strobe signal, relay driving
signal for oven function and indicator signal.
2) Power Source Circuit
This circuit generates voltages necessary for the control
unit from the AC line voltage.
In addition, the synchronizing signal is available in order
to compose a basic standard time in the clock circuit.
3) Synchronizing Signal Circuit
The power source synchronizing signal is available in
order to compose a basic standard time in the clock
circuit. It incorporates a very small error because it works
on commercial frequency.
4) Reset Circuit
A circuit to generate a signals which resetting the LSI to
the initial state when power is applied.
5) Buzzer Circuit
The buzzer is responds to signals from the LSI to emit
audible sounds (key touch sound and completion sound).
6) Door Sensing Switch
A switch to inform the LSI if the door is open or closed.
7) Relay Circuit
To drive the magnetron, fan motor, turntable motor and
light the oven lamp and hood lamp.
8) Indicator Circuit
This circuit consists of 22 segments and 3 common
electrodes using a Light Crystal Display.
9) Back Light Circuit
A circuit to drive the back light (Light emitting diodes LD1LD4).
18
Page 21
DESCRIPTION OF LSI
LSI
The I/O signal of the LSI is detailed in the following table.
Terminal to change cooking input according to the Model.
By using the A/D converter contained in the LSI, DC voltage in accordance with the Model
in operation is applied to set up its cooking constant.
To input signal which communicates the door open/close information to LSI.
Door close "H" level signal (0V). Door open "L" level signal (-5V).
Signal to sound buzzer (2.0 kHz).
A: key touch sound.
B: Completion sound.
Oven lamp, fan motor and turntable motor driving signal
To turn on and off shut off relay (RY1). The
square waveform voltage is delivered to the RY1
driving circuit and RY2 control circuit.
R-1200
R-1201
0.1 sec.
A
2.0 sec.
B
16.7 msec.
During cooking
H : GND
L : -5V
H : GND
L : -5V
H : GND
L : -5V
17-18P51-P50OUTTerminal not used.
19P47OUT
Magnetron high-voltage circuit driving signal.
To turn on and off the cook relay (RY2). The
signals holds "L" level during microwave cook-
Maximum
out put
ing and "H" level while not cooking. In other
cooking modes (variable cooking) the signal
turns to "H" level and "L" level in repetition
according to the power level.
70% of maximum
out put
20P46INSignal coming from touch key.
When either G12 line on key matrix is touched, a corresponding signal out of P20 - P27 will
be input into P46. When no key is touched, the signal is held at "H" level.
21P45IN
Signal similar to P46.
When either G11 line on key matrix is touched, a corresponding signal will be input into P45.
22P44IN
Signal similar to P46.
When either G10 line on key matrix is touched, a corresponding signal will be input into P44.
23P43IN
Signal similar to P46.
When either G9 line on key matrix is touched, a corresponding signal will be input into P43.
24INT0IN
Signal synchronized with commercial power source frequency.
This is the basic timing for time processing of LSI.
25P41OUTTerminal not used.
26P40INConnected to GND through the pull-down resistor R100.
27
RESET
IN
Auto clear terminal.
Signal is inputted to reset the LSI to the initial state when power is applied.
28-29P71-P70OUTTerminal not used.
OFF
ON
OFFOFF
24 sec.
ON
16.7 msec.
8 sec.
H : GND
L : -5V
H : GND
L : -5V
H : GND
L : -5V
19
Page 22
R-1200
R-1201
Pin No.SignalI/ODescription
30XININInternal clock oscillation frequency input setting.
The internal clock frequency is set by inserting the ceramic filter oscillation circuit with respect
to XOUT terminal.
31XOUTOUT
Internal clock oscillation frequency control output.
Output to control oscillation input of XIN.
32VSSIN
Power source voltage: -5.0V.
VC voltage of power source circuit input.
33P27OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43-P46 terminal while one of
G8 line keys on key matrix is touched.
34P26OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43-P46 terminal while one of
G7 line keys on key matrix is touched.
35P25OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43-P46 terminal while one of
G6 line keys on key matrix is touched.
36P24OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43-P46 terminal while one of
G5 line keys on key matrix is touched.
37P23OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43-P46 terminal while one of
G4 line keys on key matrix is touched.
38P22OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43-P46 terminal while one of
G3 line keys on key matrix is touched.
39P21OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43-P46 terminal while one of
G2 line keys on key matrix is touched.
40P20OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43-P46 terminal while one of
G1 line keys on key matrix is touched.
41P17OUT
Hood lamp driving signal.
To turn on and off relay(RY3). "L" level: During
Hood lamp ON. "H" level: During Hood lamp
OFF.
42P16OUT
Hood lamp driving signal.
To turn on and off relay(RY4). " L " level: During
Hood lamp ON. "H" level: During Hood lamp
OFF.
43-47P15-P11OUTTerminal not used.
48-50
51-72
SEG24-SEG22
SEG21-SEG0
OUTTerminal not used.
OUTSegment 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 20 (52) .....................SEG20 ( 2)SEG 9 (63) ......................... SEG 9 (13)
SEG 19 (53) .....................SEG19 ( 3)SEG 8 (64) ......................... SEG 8 (14)
SEG 18 (54) .....................SEG18 ( 4)SEG 7 (65) ......................... SEG 7 (15)
SEG 17 (55) .....................SEG17 ( 5)SEG 6 (66) ......................... SEG 6 (16)
SEG 16 (56) .....................SEG16 ( 6)SEG 5 (67) ......................... SEG 5 (17)
SEG 15 (57) .....................SEG15 ( 7)SEG 4 (68) ......................... SEG 4 (18)
SEG 14 (58) .....................SEG14 ( 8)SEG 3 (69) ......................... SEG 3 (19)
SEG 13 (59) .....................SEG13 ( 9)SEG 2 (70) ......................... SEG 2 (20)
SEG 12 (60) .................... SEG12 (10)SEG 1 (71) ......................... SEG 1 (21)
SEG 11 (61) .................... SEG11 (11)SEG 0 (72) ......................... SEG 0 (22)
ON
ON
OFF
OFF
H : GND
L
H : GND
L
20
Page 23
Pin No.SignalI/ODescription
73/74VCC/VREFINConnected to GND.
75AVSSINConnected to VC.
76COM3OUTTerminal not used.
77COM2OUT
Common data signal: COM2.
Connected to LCD signal COM2.
78COM1OUT
Common data signal: COM1.
Connected to LCD signal COM1.
79COM0OUT
Common data signal: COM0.
Connected to LCD signal COM0.
80VL3IN
Power source voltage input terminal.
Standard voltage for LCD.
R-1200
R-1201
21
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R-1200
R-1201
SERVICING
1. Precautions for Handling Electronic Components
This unit uses CMOS LSI in the integral part of the
circuits. When handling these parts, the following precautions should be strictly followed. CMOS LSI have
extremely high impedance at its input and output terminals. For this reason, it is easily influenced by the
surrounding high voltage power source, static electricity
charge in clothes, etc. and sometimes it is not fully
protected by the built-in protection circuit.
In order to protect CMOS LSI.
1) When storing and transporting, thoroughly wrap them in
aluminium foil. Also wrap all PW boards containing them
in aluminium foil.
2) When soldering, ground the technician as shown in the
figure and use grounded soldering iron and work table.
approx. 1M ohm
2. Shapes of Electronic Components
Transistor
KRA101M
KRC243M
B
C
E
3. Servicing of Touch Control Panel
We describe the procedures to permit servicing of the
touch control panel of the microwave oven and the
precautions you must take when doing so. To perform
the servicing, power to the touch control panel is available either from the power line of the oven itself or from
an external power source.
(1)Servicing the touch control panel with power supply
of the oven:
CAUTION: THE HIGH VOLTAGE TRANSFORMER OF THE
MICROWAVE OVEN IS STILL LIVE DURING
SERVICING AND PRESENTS A HAZARD.
Therefore, before checking the performance of the touch
control panel,
1) Disconnect the power supply cord, and then remove
outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Disconnect the leads to the primary of the power
transformer.
5) Ensure that these leads remain isolated from other
components and oven chassis by using insulation
tape.
6) After that procedure, re-connect the power supply
cord.
After checking the performance of the touch control
panel,
1) Disconnect the power supply cord.
2) Open the door and block it open.
3) Re-connect the leads to the primary of the power
transformer.
4) Re-install the outer case (cabinet).
5) Re-connect the power supply cord after the outer case
is installed.
6) Run the oven and check all functions.
A. On some models, the power supply cord between the
touch control panel and the oven itself is so short that the
two can’t be separated. For those models, check and
repair all the controls (sensor-related ones included) of
the touch control panel while keeping it connected to the
oven.
B. On some models, the power supply cord between the
touch control panel and the oven proper is long enough
that they may be separated from each other. For those
models, it is possible to check and repair the controls of
the touch control panel while keeping it apart from the
oven proper; in this case you must short both ends of the
door sensing switch (on PWB) of the touch control panel
with a jumper, which activates an operational state that
is equivalent to the oven door being closed. As for the
sensor-related controls of the touch control panel, checking them is possible if dummy resistor(s) with resistance
equal to that of the controls are used.
(2)Servicing the touch control panel with power supply
from an external power source:
Disconnect the touch control panel completely from the
oven proper, and short both ends of the door sensing
switch (on PWB) of the touch control panel, which
activates an operational state that is equivalent to the
oven door being closed. Connect an external power
source to the power input terminal of the touch control
panel, then it is possible to check and repair the controls
of the touch control panel it is also possible to check the
sensor-related controls of the touch control panel by
using the dummy resistor(s).
4. Servicing Tools
Tools required to service the touch control panel assembly.
1) Soldering iron: 30W
(It is recommended to use a soldering iron with a grounding terminal.)
2) Oscilloscope: Single beam, frequency range: DC-10MHz
type or more advanced model.
3) Others: Hand tools
5. Other Precautions
1) Before turning on the power source of the control unit,
remove the aluminium foil applied for preventing static
electricity.
2) Connect the connectors of the key unit to the control unit
being sure that the lead wires are not twisted.
3) After aluminium foil is removed, be careful that abnormal
voltage due to static electricity etc. is not applied to the
input or output terminals.
4) Attach connectors, electrolytic capacitors, etc. to PWB,
making sure that all connections are tight.
5) Be sure to use specified components where high precision is required.
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R-1200
R-1201
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
W ARNING AGAINST HIGH VOL T AGE:
Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts may
result in severe, possibly fatal, electric shock.
(Example)
High Voltage Capacitor, Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..
WARNING:
1. Disconnect the power supply cord.
2. Make sure that a definite” click” can be heard when the
microwave oven door is unlatched. (Hold the door in a
closed position with one hand, then 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.).
Carry out any remedial work that is necessary before
operating the oven.
Do not operate the oven if any of the following conditions
exist;
Avoid possible exposure to microwave energy. Please follow the instructions below before
operating the oven.
W ARNING 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:
Oven lamp, Magnetron, Power transformer and Oven
cavity.
1. Door does not close firmly.
2. Door hinge, support or latch hook is damaged.
3. The door gasket or seal is damaged.
4. The door is bent or warped.
5. There are defective parts in the door interlock system.
6. There are defective parts in the microwave generating
and transmission assembly.
7. There is visible damage to the oven.
Do not operate the oven:
1. Without the RF gasket (Magnetron).
2. If the wave guide or oven cavity are not intact.
3. If the door is not closed.
4. If the outer case (cabinet) is not fitted.
3) Sharp edge:
Base cover, Base plate R, Oven cavity, Waveguide
flange, Chassis support and other metallic plate.
4) Movable parts (to prevent a fault)
Fan blade, Fan motor, Switch, Open lever, Open
button and Mounting lever.
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, RIGHT PANEL PARTS, DOOR PARTS’, when carrying out any of the
following removal procedures:
THE FOLLOWING ADJUSTMENTS OR COMPONENT REPLACEMENT CAN BE PERFORMED
WITHOUT REMOVING THE OVEN FROM THE WALL
1. Hood lamps, sockets.
2. Base cover and hood lamp glass assembly.
3. Turntable motor.
4. Right panel parts
REMOVAL OF OVEN FROM WALL (Two persons recommended to remove the oven)
1. Disconnect the power supply cord, and uncoil the power
supply cord.
2. To discharge the high voltage capacitor, wait for 60
seconds.
3. Remove the turntable tray and support from the oven cavity.
4. Remove the two (2) screws holding the oven (outer case
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R-1200
R-1201
cabinet) to the top cabinet.
5. While supporting the front of the oven, pull down the two
(2) mounting levers and release the oven from the unit
mounting plate.
6. Pull the power cord out of the wall cabinet and remove
OUTER CASE REMOVAL
Remove the oven from the wall, referring to "REMOVAL OF
OVEN FROM WALL" and proceed as follows;
1. Disconnect the power supply cord.
2. Open the door and block it open.
3. To discharge the high voltage capacitor, wait for 60
seconds.
4. Remove the four (4) screws from the rear of the outer
case cabinet and one (1) screw at right side.
5. Slide the outer case cabinet back about 1 inch (3 cm) to
free it from retaining clips on the cavity face plate.
6. Disconnect the three (3) pin connector of the power
supply cord from the wiring harness and remove the
power supply cord together with the outer case.
POWER TRANSFORMER REMOVAL
1. Disconnect the power supply cord, remove the oven
from wall, and remove outer case. (Refer to procedure of
"REMOVAL OF OVEN FROM WALL" AND "OUTER
CASE REMOVAL".) And proceed as follows.
2. Open the door and block it open.
3. To discharge the high voltage capacitor, wait for 60
seconds.
4. Disconnect main wire harness from transformer.
5. Disconnect high voltage wire A from the transformer.
6. Disconnect filament leads of transformer from the
magnetron and capacitor.
7. Remove two (2) screws holding the transformer to base
plate R.
the oven.
7. The oven is now free and can be placed on the work
surface selected for servicing the oven.
8. Installation is the reverse of this procedure.
7. Nip the cord bushing with bushing pliers and release it
from the outer case cabinet.
8. Remove the cord bushing and the power supply cord
from the outer case cabinet.
9. Now, the power supply cord is free.
CAUTION: 1. DISCONNECT OVEN FROM POWER
SUPPLY BEFORE REMOVING OUTER
CASE.
2. DISCHARGE THE HIGH VOLTAGE
CAPACITOR BEFORE TOUCHING ANY
OVEN COMPONENTS OR WIRING.
Reinstall
1. Install by sliding the transformer on the base plate R with
its primary terminals toward the outer case.
2. Secure the transformer with two (2) screws to base plate
R.
3. Reconnect wire leads (primary and high voltage) to the
transformer and filament leads of transformer to
magnetron and high voltage capacitor. Refer to
"PICTORIAL DIAGRAM".
4. Reinstall the outer case and check that oven is operating
properly.
CAUTION: MAKE SURE THE WIRE LEADS NEVER
TOUCH THE FAN BLADE.
MAGNETRON REMOVAL
1. Disconnect the power supply cord , remove the oven
from wall and remove outer case (Refer to procedure of
"Removal of Oven from Wall" and "Outer case Removal".)
2. Open the door and block it open.
3. To discharge the high voltage capacitor, wait for 60
seconds.
4. Disconnect the high voltage wire lead of the high voltage
rectifier assembly from the magnetron.
5. Disconnect the filament lead of the transformer from the
magnetron.
6. Remove the one (1) screw holding the magnetron duct
to the oven cavity top plate.
HIGH VOLTAGE RECTIFIER AND HIGH VOLTAGE CAPACITOR REMOVAL
1. Disconnect the power supply cord , remove the oven
from wall and remove outer case (Refer to procedure of
"Removal of Oven from Wall" and "Outer case Removal".)
2. Open the door and block it open.
3. To discharge the high voltage capacitor, wait for 60
7. Remove the magnetron duct from the oven cavity, by
releasing the tab of the magnetron duct from the oven
cavity top plate.
8. Carefully remove four (4) mounting screws holding the
magnetron to waveguide. When removing the screws
hold the magnetron to prevent it from falling.
9. Remove the magnetron from the unit with care so the
magnetron tube should not be hit by any metal object
around the tube.
CAUTION: WHEN REPLACING THE MAGNETRON, BE
SURE THE R.F. GASKET IS IN PLACE AND
MOUNTING SCREWS ARE TIGHTENED SECURELY.
seconds.
4. Disconnect the high voltage wire lead with high voltage
rectifier from the magnetron.
5. Disconnect filament lead of the transformer from high
voltage capacitor.
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R-1200
R-1201
6. Disconnect high voltage wire A from capacitor.
7. Remove the fan duct assembly from the oven cavity,
referring to the procedure of "COOLING FAN MOTOR
REMOVAL"
8. Remove one (1) screw holding capacitor holder and high
voltage rectifier to the fan duct.
9. Disconnect the high voltage rectifier assembly from the
high voltage capacitor.
TEMPERATURE FUSE (CAVITY) REMOVAL
1. Disconnect the power supply cord and remove the oven
from wall and remove outer case. (Refer to procedure of
"Removal of Oven from Wall" and "Outer case Removal")
2. Open the door and block it open.
3. To discharge the high voltage capacitor, wait for 60
seconds.
4. Disconnect the wire leads from the temperature fuse
TEMPERATURE FUSE (MAGNETRON) REMOVAL
1. Disconnect the power supply cord and remove the oven
from wall and remove outer case. (Refer to procedure of
"Removal of Oven from Wall" and "Outer case Removal")
2. Open the door and block it open.
3. To discharge the high voltage capacitor, wait for 60
seconds.
10.Now, the high voltage rectifier assembly is free.
11.Remove capacitor from the holder.
12.Now, the high voltage capacitor is free.
CAUTION: WHEN REPLACING THE HIGH VOLTAGE
RECTIFIER ASSEMBLY, THE GROUND SIDE
TERMINAL MUST BE SECURED FIRMLY
WITH A GROUNDING SCREW.
(cavity).
5. Remove the one (1) screw holding the temperature fuse
(cavity) to the oven cavity top plate.
6. Remove the temperature fuse (cavity) from the holder
at the oven cavity top plate.
7. Now, temperature fuse (cavity) is free.
4. Disconnect the wire leads from the temperature fuse
(Magnetron).
5. Remove the one (1) screw holding the temperature fuse
(Magnetron) to the fan duct.
6. Now, the temperature fuse (Magnetron) is free.
COOLING FAN MOTOR REMOVAL
1. Disconnect the power supply cord, remove the oven
from wall and remove outer case (Refer to procedure of
"Removal of Oven from Wall" and "Outer case Removal".)
2. Open the door and block it open.
3. To discharge the high voltage capacitor, wait for 60
seconds.
4. Disconnect the wire leads from the fan motor.
5. Disconnect the high voltage wire lead with the high
voltage rectifier from the magnetron.
6. Disconnect the filament lead of the transformer from the
high voltage capacitor.
7. Disconnect the high voltage wire A from the capacitor.
8. Release the wire leads from the hole of the fan duct.
9. Remove the one (1) screw holding the fan duct to the
magnetron.
10.Remove two (2) screws holding the fan duct to oven
cavity top plate and the base plate R.
11. Remove the fan duct assembly from the oven cavity.
12.Remove the fan blade from the fan motor shaft according
the following procedure.
13.Hold the edge of the rotor of the fan motor by using a pair
of groove joint pliers.
CAUTION:
* Make sure that any pieces do not 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 damaged.
* Do not disfigure the bracket by touching with the
pliers.
14.Remove the fan blade from the shaft of the fan motor by
pulling and rotating the fan blade with your hand.
15. Now, the fan blade will be free.
CAUTION:
* Do not reuse the removed fan blade because the
hole (for shaft) may be larger than normal.
16.Remove the two (2) screws holding the fan motor to the
fan duct.
17.Now, the fan motor is free.
INSTALLATION
1. Install the fan 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. 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.
4. Install the fan motor to the hood duct with the two (2) screws.
CAUTION:
* Do not hit the fan blade with excessive force when
installing because the bracket may be disfigured.
* Make sure that the fan blade rotates smooth after
installation.
* Make sure that the axis of the shaft is not slanted.
5. Install the fan duct to the oven cavity top plate and base
plate R with the two (2) screws.
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R-1200
R-1201
6. Hold the fan duct to the magnetron with the one (1) screw.
7. Reconnect the wire leads to the fan motor, magnetron
and high voltage capacitor, referring to the pictorial
diagram.
Coil
Groove joint pliers
Stator
Gap
Bracket
Rotor
Rear View
Shaft
Axis
Stator
Rotor
Side View
TURNTABLE MOTOR AND FOOD LAMP SOCKETS REMOVAL
1. Disconnect the power supply cord.
2. Open the door and block it open.
3. To discharge the high voltage capacitor, wait for 60
seconds.
4. Remove the one (1) screw holding the base cover to the
oven cavity back plate.
5. Remove the three (3) screws holding the base cover to
the oven cavity front face plate.
6. Open the base cover.
7. Release the two hood lamp sockets from the base cover.
8. Remove the base cover from the oven cavity by pulling
down and moving to the left slightly.
8. Reinstall the wire leads to the hole of the fan duct.
9. Refer to procedure of "OUTER CASE REMOVAL". And
reverse their procedure. And reinstall the outer case.
Shaft
These are the positions
that should be pinched
with pliers
Table
Center of
bracket
TURNTABLE MOTOR
9. Disconnect the wire leads from the turntable motor.
10.Remove one (1) screw holding turntable motor to the
oven cavity.
11.Now the turntable motor is free.
HOOD LAMP SOCKET
9. Screw the hood lamp off from the lamp socket.
10.Disconnect the wire leads from the lamp socket by
pushing the terminal hole of the lamp socket with the
small flat type screw driver.
11. Now, the lamp socket is free.
OVEN LAMP AND LAMP SOCKET REMOVAL
1. Disconnect the power supply cord and remove the oven
from wall and remove outer case. (Refer to procedure of
"Removal of Oven from Wall" and "Outer case Removal")
2. Open the door and block it open.
3. To discharge the high voltage capacitor, wait for 60
seconds.
4. Turn the lamp socket and release it from the magnetron
duct.
5. Screw the oven lamp off from the lamp socket.
6. Now, the oven lamp is free.
7. Pull the wire leads from the oven lamp socket by pushing
POSITIVE LOCK® CONNECTOR (NO-CASE TYPE) REMOVAL
1. Disconnect the power supply cord and remove the oven
from wall and remove outer case. (Refer to procedure of
"Removal of Oven from Wall" and "Outer case Removal")
2. Open the door and block it open.
3. To discharge the high voltage capacitor, wait for 60
seconds.
4. Push the lever of positive lock® connector.
5. Pull down on the positive lock® connector.
CAUTION: WHEN CONNECTING THE POSITIVE LOCK
CONNECTORS TO THE TERMINALS, INSTALL THE POSITIVE LOCK® SO THAT THE
LEVER FACES YOU.
the terminal hole of the oven lamp socket with the small
flat type screw driver.
8. Now, the oven lamp socket is free.
Oven lamp
socket
Terminal
Wire lead
Flat type small
screw driver
Positive lock®
connector
Lever
®
Positive lock® connector
Terminal hole
Terminal
1
Push
2
Pull down
26
Page 29
RIGHT PANEL ASSEMBLY AND POWER UNIT REMOVAL
R-1200
R-1201
1. Disconnect the power supply cord.
2. Open the door and block it open.
3. To discharge the high voltage capacitor, wait for 60
seconds.
4. Remove one (1) screw holding the right panel to the oven
cavity front face plate.
5. Release the right panel from the oven cavity front face
plate by lifting it up.
6. Disconnect the wire leads from the relays RY1 and RY2.
7. Disconnect the connectors CN-A, CN-B and CN-C from
the control unit.
8. Remove the right panel assembly from the oven.
9. Now, the right panel assembly is free.
10.Remove the two (2) screws holding the power unit to
the right panel.
11.Release the two (2) tabs holding the power unit to the
right panel.
12.Now, the power unit is free.
DOOR SENSING SWITCH, PRIMARY INTERLOCK SWITCH AND MONITOR SWITCH REMOVAL
1. Disconnect the power supply cord and remove the oven
from wall and remove outer case. (Refer to procedure of
"Removal of Oven from Wall" and "Outer case Removal")
2. Open the door and block it open.
3. To discharge the high voltage capacitor, wait for 60
seconds.
4. Remove the right panel assembly, referring to the
procedure of "RIGHT PANEL ASSEMBLY AND POWER
UNIT REMOVAL".
5. Remove the two (2) screws holding the latch hook to the
oven cavity front flange.
6. Remove the latch hook from the oven cavity front flange.
7. Disconnect the wire leads of each switch.
8. Remove each switch from the latch hook by pushing the
one (1) stopper tab holding each switch.
9. Now, each switch is free.
Reinstall
1. Reinstall each switch in its place. The primary interlock
switch is in the lower position, door sensing switch is in
the upper position and the monitor switch is in the middle
position.
2. Reconnect wire leads to each switch. Refer to pictorial
diagram.
3. Secure the latch hook (with two (2) mounting screws) to
oven cavity front flange.
4. Make sure that the monitor switch is operating properly
and check continuity of the monitor circuit. Refer to
chapter "Test Procedure" and "Adjustment procedure".
DOOR SENSING SWITCH, PRIMARY INTERLOCK SWITCH AND MONITOR SWITCH ADJUSTMENT
1. Disconnect the power supply cord and remove the oven
from wall and remove outer case. (Refer to procedure of
"Removal of Oven from Wall" and "Outer case Removal")
2. Open the door and block it open.
3. To discharge the high voltage capacitor, wait for 60
seconds.
4. Remove the right panel assembly, referring to the
procedure of "RIGHT PANEL ASSEMBLY AND POWER
UNIT REMOVAL".
If the door sensing switch, primary interlock switch and
monitor switch do not operate properly due to a
misadjustment, the following adjustment should be made.
5. Loosen the two (2) screws holding latch hook to the oven
cavity front flange.
6. 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 primary interlock switch are activated with the
door closed. The horizontal position of the latch hook
should be adjusted so that the monitor switch is activated
with the door closed.
7. Secure the screws with washers firmly.
8. Check all of the switches operation. If any switch has not
activated with the door closed, loosen screw and adjust
the latch hook position.
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)
should be less than 0.5mm.
2. The door sensing switch and primary interlock switch
interrupt the circuit before the door can be opened.
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.)
Latch heads
Latch hook
Door sensing
Door
Open lever
switch
Monitor switch
Primary interlock switch
Figure C-1. Latch Switch Adjustments
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R-1200
R-1201
DOOR REPLACEMENT
DOOR ASSEMBLY REMOVAL
1. Disconnect the power supply cord and remove the oven
from wall and remove outer case. (Refer to procedure of
"Removal of Oven from Wall" and "Outer case Removal")
2. Open the door and block it open.
3. To discharge the high voltage capacitor, wait for 60
seconds.
4. Disconnect the 9-pin wire harness from the power unit.
5. Release a snap band of the 9-pin wire harness from the
hole on the base plate R.
6. Remove the two (2) screws holding the bottom sash to
the oven cavity front face plate.
7. Remove the bottom sash with 9-pin wire harness from the
oven cavity front face plate. And remove the connecter
of the 9-pin wire harness from the long hole of the oven
cavity front face plate.
8. Remove the 9-pin wire harness from the bottom sash.
9. Insert a putty knife (thickness of about 0.5mm) into the
gap A between the upper door stopper and the choke
cover as shown in Figure C-4 to free engaging parts.
10.Lift up the upper door stopper.
11.Remove the lower door stopper from the door assembly
in a similar way which the upper door stopper is removed.
12.Now, the upper and lower door stoppers are free from
the door assembly.
13.Lift up the door assembly to release the upper and lower
door hinge pins from the upper and lower oven hinges.
14.Now, the door assembly is free.
Note: When the individual parts are replaced, refer to
"Door Disassembly".
DOOR ASSEMBLY REINSTALL
1. On reinstalling door, insert the lower oven hinge to lower
door hinge pin.
2. Insert the upper oven hinge to the upper door hinge pin.
3. Shut the door (close the contacts of interlock switches).
4. Make sure upper and lower oven hinges are inserted into
the upper an lower door hinge pins.
5. Make sure the door is parallel with oven face lines (left
and upper side lines) and door latch heads pass through
latch holes correctly.
6. Reinstall the upper and lower door stoppers to the door
assembly.
7. Reinstall the 9-pin wire harness into the bottom sash.
The 9-pin wire harness should be held by three (3) tabs
on the bottom sash. And the marking portion on the 9pin wire harness should be held by left tab as shown in
Figure C-3.
8. Insert the connector of the 9-pin wire harness into the
long hole of the oven cavity front face plate. And reinstall
the bottom sash to the oven cavity front face plate with
the two (2) screws.
9. Reconnect the 9-pin wire harness to the power unit.
10. Insert the snap band of the 9-pin wire harness into the
hole on the base plate R.
Note: After any service to the door;
(A) Make sure that door sensing switch and primary
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 servicing, 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. Reinstall outer case and check for microwave leakage
around door with an approved microwave survey meter.
(Refer to Microwave Measurement Procedure.)
Note: The door on a microwave oven is designed to
act as an electronic seal preventing the leakage
of microwave energy from oven cavity during
cook cycle. This function does not require that
door be air-tight, moisture (condensation)-tight
or light-tight. Therefore, occasional appearance
of moisture, light or sensing of gentle warm air
movement around oven door is not abnormal
and do not of themselves indicate a leakage of
microwave energy from oven cavity.
Upper door
hinge pin
Upper oven
hinge
RE-INSTALL
Door assembly
Latch
heads
Lower
oven
hinge
Upper door
stopper
Lower door
hinge pin
RE-INSTALL
Lower door
stopper
Bottom
sash
9-pin wire
harness
Figure C-2. Door Replacement and adjustment
Screw
Oven cavity
Door
assembly
Tabs
Bottom sash
front face plate
Marking
Screw
Connector
9-pin wire
harness
Figure C-3. 9-pin wire harness and bottom sash
28
Page 31
DOOR DISASSEMBLY
R-1200
R-1201
1. Disconnect the power supply cord.
2. Open the door and block it open.
3. To discharge the high voltage capacitor, wait for 60
seconds.
4. Remove door assembly, referring to "DOOR
REPLACEMENT".
Replacement of door components are as follows:
5. Place door assembly on a soft cloth with latches facing
up.
Note: As the engaging part of choke cover and door frame
are provided at 15 places, do not force any particular
part.
CHOKE COVER
6. Insert a putty knife (thickness of about 0.5mm) into the
gap between the choke cover and door frame as shown
Figure C-4 to free engaging parts.
7. Pry the choke cover by inserting a putty knife in order
shown in Figure C-4.
8. Now choke cover is free from door panel and door frame.
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.
DOOR FRAME ASSEMBLY
9. Remove four (4) screws holding the door panel to the
door frame assembly.
10.Release the door panel from the door frame assembly.
NOTE: It is easier to release the engaging parts of the upper
or lower door hinge pin side at first.
11.Now, door frame assembly is free.
LATCH SPRING, LATCH HEAD AND DOOR PANEL
12.Release the latch spring from the tab of the latch head
and tab of the door frame.
13.Release the latch head from the door frame.
14.Now, the latch spring and latch head are free.
Upper door stopper
A
Choke cover
Putty knife
Lower
door stopper
12.Releasing the two (2) lower tabs, remove the LSI unit
with the LCD holder from the door frame assembly.
13.Disconnect the 9-pin wire harness from the LSI unit.
14.Releasing the two (2) tabs, release the LCD from the
LCD holder.
15.Releasing the four (4) tabs, remove the LCD holder from
the LSI unit.
16.Now the LSI unit is free.
NOTE: For 9-pin wire harness
1. When the PWB cover is reinstalled, route the 9-pin
wire harness under the hole of the PWB cover as
shown in Figure C-5.
2. Before the door panel is reinstalled to the door frame
assembly, make sure that the 9-pin wire harness is
held by the two (2) tabs and one (1) hole on the door
frame as shown in Figure C-5. And the marking
portion on the 9-pin wire harness should be held by
right tab on the door frame as shown in Figure C-5.
Screws
Tab
Door frame
PWB cover
Cushion
Hole
TabsLSI unit
Tab
9-pin wire
harness
Tab
Tab
Marking
Tab
9-pin wire
harness
Hole
Figure C-5. Door frame assembly
NOTE: For key unit
1. Before attaching a new key unit, wipe off remaining
adhesive on the door frame surfaces completely with
a soft cloth soaked in alcohol.
2. When attaching the key unit to the door frame, adjust
the upper edge and left edge of the key unit to the
correct position of door frame.
3. Stick the key unit firmly to the door frame by rubbing
with soft cloth not to scratch.
NOTE: For LSI unit
Handle the LSI unit carefully so that the ribbon cable
does not come off. Because the ribbon cable is
glued on the LCD and the printed wiring board only
by heated paste.
Ribbon cable
Door frame
Figure C-4. Door Disassembly
LSI UNIT
9. Remove the two (2) screws holding the PWB cover to
the door frame assembly.
10.Remove the PWB cover from the door frame assembly.
11.Disconnect the ribbon cable of the key unit from the LSI
unit.
5- 4PSHEPB021MRE0MSealer film 1AE
5- 5XCPSD40P08000MScrew : 4mm x 8mm 4AA
MISCELLANEOUS
6- 1CFZK-B460MRK0MInstallation material assembly 1AH
6-1-1LBSHC0040MRE0MGrommet 1AC
6-1-2LX-BZ0195WRE0MToggle screw 4AC
6-1-3LX-MZB001MRE0MCord holder 1AB
6-1-4XBRSD50P60000MScrew : 5mm x 60mm2AA
6-1-5XOTSD40P12000MScrew : 4mm x 12mm3AA
6-1-6XTSSD50P35000MScrew : 5mm x 35mm6AA
6-1-7XWHSD50-16300MWasher2AA
6- 2LANG-B003MRP0MScale plate2AE
6- 3TINSEB298MRK0MOperation manual1AE
6- 4TINSKB082MRR0MTop and Wall template1AE
6- 5FW-VZB188MRE0MLow voltage harness1AT
6- 6QW-QZB025MRE0MHigh voltage wire A1AT
6- 7FW-VZB190MRE0MMain harness1AU
6- 8TCAUAB041MRR0MDHHS service caution label 2AA
6- 9TCAUAB037MRR0MMonitor caution label 1AA
6-10TCAUAB005MRR0MRevised DHHS/GRD C/label 1AB
SCREWS, NUTS AND WASHERS
7- 1XOPSD40P12000MScrew : 4mm x 12mm 7AA
7- 2XOTSF40P12000MScrew : 4mm x 12mm [R-1200]6AA
7- 2XOTSE40P12000MScrew : 4mm x 12mm [R-1201]6AA
7- 3XOTSD40P12000MScrew : 4mm x 12mm8AA
7- 4XHTSD40P08RV0MScrew : 4mm x 8mm 2AA
7- 5LX-CZA038WRE0MSpecial screw5AA
7- 6LX-CZ0052WRE0MSpecial screw2AA
7- 7LX-BZA041WRE0MSpecial screw5AA
7- 8XCBSD30P08000MScrew : 3mm x 8mm 3AA
7- 9XOTSD40P08000MScrew : 4mm x 8mm1AA
R-1200
R-1201
35
Page 38
R-1200
R-1201
HOW TO ORDER REPLACEMENT PARTS
To have your order filled promptly and correctly, please furnish the following information.
1. MODEL NUMBER2. REF. NO.3. PART NO.4. DESCRIPTION
Order Parts from the authorized SHARP parts Distributor for your area.
Defective parts requiring return should be returned as indicated in the Service Policy.
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.
38
'01 SHARP CORP. (12S1.730E) Printed in U.S.A
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