Sharp R1481 Manual

							R-1480
R-1481
R-1482
In the interest of user-safety the oven should be restored to its original
condition and only parts identical to those specified should be used.
WARNING TO SERVICE PERSONNEL: Microwave ovens con-
tain circuitry capable of producing very high voltage and
current, contact with following parts may result in a severe,
possibly fatal, electrical shock. (High Voltage Capacitor, High
Voltage Power Transformer, Magnetron, High Voltage Recti-
fier Assembly,  High Voltage Harness etc..)
TABLE OF CONTENTS
Page
PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO
AVOID POSSIBLE  EXPOSURE TO EXCESSIVE MICROWAVE ENERGY ................... INSIDE FRONT COVER
BEFORE SERVICING ...................................................................................................... INSIDE FRONT COVER
WARNING TO SERVICE PERSONNEL ................................................................................................................ 1
MICROWAVE MEASUREMENT PROCEDURE ................................................................................................... 2
FOREWORD AND WARNING ............................................................................................................................... 3
PRODUCT SPECIFICATIONS .............................................................................................................................. 4
GENERAL  INFORMATION ................................................................................................................................... 4
OPERATION .......................................................................................................................................................... 6
TROUBLESHOOTING GUIDE ............................................................................................................................ 11
TEST PROCEDURE ............................................................................................................................................ 12
TOUCH CONTROL PANEL ASSEMBLY ............................................................................................................ 21
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ................................................................ 26
PICTORIAL DIAGRAM ........................................................................................................................................ 34
CONTROL PANEL CIRCUIT ............................................................................................................................... 35
PRINTED WIRING BOARD ................................................................................................................................. 36
PARTS LIST ........................................................................................................................................................ 37
PACKING AND ACCESSORIES ......................................................................................................................... 42S3807R1480X//
R-1480
R-1481
R-1482
OVER THE  RANGE
MICROWAVE OVEN
MODELS
 SERVICE MANUAL
SHARP CORPORATION
This document has been published to be used for after
sales service only.
The contents are subject to change without notice.
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CUSTOM HELP1 Coffee/tea
2 Roll/muffin, fresh
3 Roll/muffin, frozen
4 Hot cereal
5 Scrambled eggs

1 Dinner plate
2 Pasta/casserole
3 Frozen entree
4 Frozen snack
5 Pizza, slice
1 Baked potatoes
2 Fresh vegetables
3 Frozen vegetables
4 Rice
5 Ground meatPOPCORN
COMPU DEFROST
POWER
LEVELKITCHEN TIMER
CLOCKMINUTE
PLUS
TURNTABLE
ON/OFFSTOP
CLEARSTART
TOUCH ONWORK
LIGHTNIGHT
LIGHTFAN
HI/LO
BREAKFAST
COMPU COOK SNACKS &
REHEAT 
						

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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 releasing oven 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 Administrations
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/cm
2. The owner of the unit should be instructed not to use the unit
until the oven has been brought into compliance. 
						

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WARNING TO SERVICE PERSONNEL
Microwave ovens contain circuitry capable of pro-
ducing very high voltage and current, contact with
following parts 
 may result in a severe, possibly
fatal, electrical shock.
(Example)
High Voltage Capacitor, High Voltage Power Trans-
former, Magnetron, High Voltage Rectifier Assem-
bly,  High Voltage Harness etc..
Read the Service Manual carefully and follow all
instructions.
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 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 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 microwave leakage test should be  carried out.
Dont Touch !
Danger High Voltage 
						

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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/cm
2 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/cm
2 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±5ûC (68ûF) 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/cm
2,
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. 
						

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SHARP ELECTRONICS CORPORATION
SHARP PLAZA, MAHWAH,
NEW JERSEY 07430-2135
SERVICE MANUAL
OVER THE RANGE
MICROWAVE OVEN
R-1480 / R-1481 / R-1482
FOREWORD
This Manual has been prepared to provide Sharp Electronics Corp.
Service Personnel with Operation and Service Information for the
SHARP OVER THE RANGE  MICROWAVE OVEN, R-1480, R-1481,
R-1482.
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.
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 Ò*Ó 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 ÒDÓ on parts list may cause undue microwave
exposure, by themselves, or when they are damaged, loosened
or removed.PRODUCT DESCRIPTION
GENERAL INFORMATION
OPERATION
TROUBLESHOOTING GUIDE AND
TEST PROCEDURE
TOUCH CONTROL PANEL
COMPONENT REPLACEMENT
AND ADJUSTMENT PROCEDURE
WIRING DIAGRAM
PARTS LIST 
						

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ITEM DESCRIPTION
Power Requirements 120 Volts / 14.3 Amperes
60 Hertz
Single phase, 3 wire grounded
Power Output 950 watts (IEC-705 TEST PROCEDURE)
Operating frequency of 2450MHz
Convection Power Output 1700 watts
Case Dimensions Width 29-15/16
Height 16-3/8
Depth  15- 1/4 (Not including the door handle)
Cooking Cavity Dimensions Width 20-1/4
Height 8-3/16
1.4 Cubic Feet Depth  14-1/2
Hood lamp 2 bulbs, 30W x 2,  Incandescent light bulbs
Hood fan Approx. 300 C.F.M.
Control Complement Touch Control System
Clock ( 1:00 - 12:59 )
Timer (0 - 99 min. 99 seconds)
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
CUSTOM HELP pad, BREAKFAST pad, POPCORN pad,
SNACKS & REHEAT pad, COMPU DEFROST pad, COMPU COOK pad,
Number selection pads, POWER LEVEL pad, KITCHEN TIMER / CLOCK pad
MINUTE PLUS pad, TURNTABLE ON / OFF pad, START / TOUCH ON pad
WORK LIGHT pad, NIGHT LIGHT pad, FAN HI / LO pad
Oven Cavity Light 30W x 1 Incandescent light bulb
Safety Standard UL Listed                FCC Authorized
DHHS Rules, CFR, Title 21, Chapter 1, Subchapter J
Weight Approx. 55 lbs.
PRODUCT SPECIFICATION
GENERAL INFORMATION
GROUNDING INSTRUCTIONS
This oven is equipped with a three prong grounding plug. It must be plugged into a wall receptacle that is properly installed
and grounded in accordance with the National Electrical Code and local codes and ordinances.
In the event of an electrical short circuit, grounding reduces the risk of electric shock by providing an escape wire for the
electric current.
WARNING: Improper use of the grounding plug can result in a risk of electric shock. 
						

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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 branch circuit, using
a grounded receptacle. The receptacle should be located inside the cabinet directly above the Microwave Oven/Hood
system mounting location.
OVEN DIAGRAM
1. Oven door with see-through window.
2. Door hinges.
3. Stirrer 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. Auto-Touch control panel.8. Time display: Digital display, 99 minutes 99 seconds.
9. Ventilation openings.
10. Light Cover.
11. Grease filters.
12. Removable turntable.
The turntable will rotate clockwise or counterclockwise.
Only remove for cleaning.
13. Removable turntable support.
14. Power supply cord
10
11 12
8
7
14
6
9
3
4
5
1
9
13
2
3-Pronged Plug
Grounded
Receptacle Box
Grounding Pin
3-Pronged Receptacle 
						

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MIX CONV COOK LBS KGTURNTABLEOFF HELP
 CONTROL PANEL
OPERATION
DESCRIPTION OF OPERATING SEQUENCE
The following is a description of component functions during
oven operation.
OFF CONDITION
Closing the door activates the door sensing switch and
secondary interlock 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 , , ,
,, , ,
  and                .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)
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CUSTOM HELP
1 Coffee/tea
2 Roll/muffin, fresh
3 Roll/muffin, frozen
4 Hot cereal
5 Scrambled eggs

1 Dinner plate
2 Pasta/casserole
3 Frozen entree
4 Frozen snack
5 Pizza, slice
1 Baked potatoes
2 Fresh vegetables
3 Frozen vegetables
4 Rice
5 Ground meat
POPCORN
COMPU DEFROST
POWER
LEVELKITCHEN TIMER
CLOCKMINUTE
PLUS
TURNTABLE
ON/OFFSTOP
CLEARSTART
TOUCH ON
WORK
LIGHTNIGHT
LIGHTFAN
HI/LO
BREAKFAST
COMPU COOK SNACKS &

REHEAT 
						

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RELAY CONNECTED COMPONENTS
RY1 Oven lamp / Fan motor / Stirrer motor
RY2 Power transformer
RY3 Turntable motor
RY4 Hood fan motor
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 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, secondary interlock switch
and primary interlock relay are activated with the following
results. The circuits to the stirrer motor, the cooling fan
motor, the turntable motor, and the high voltage
components are de-energized, and the digital read-out
displays the time still remaining in the cook cycle when
the door was opened.
7. The monitor switch is electrically monitoring the operation
of the secondary interlock switch and primary interlock
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
primary interlock relay and secondary interlock switch
open their contacts, and 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 secondary interlock switch and door
sensing switch close.
If the secondary interlock switch and primary 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, secondary interlock
switch and primary interlock relay (RY2), causing the moni-
tor 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-MODE ON TIME OFF 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. 2 seconds are needed for heating of the
magnetron filament.
COMPU COOK
COMPU COOK will automatically compute the microwave
power and cooking time. Set the desired program by touch-
ing one of the COMPU COOK pad, and number pad to
select menu. Enter the weight or quantity by touching the
Number pads. When the START pad is touched, the follow-
ing operations occur:
1. The COOK indicator will light.
2. The cooking time will appear on the display and start
counting down to zero. The cooking time is adjusted
automatically according to the weight of the food.
3. The shut-off relays (RY1, RY2 and RY3) are energized,
turning on the oven lamp, turntable motor, cooling fan
motor and convection motor. The power supply voltage
is applied to the heating element.
4. Now, the oven is in the microwave cooking mode.
COMPU DEFROST COOKING
The COMPU DEFROST key is a special function key to
defrost meats and poultry faster and better. COMPU DE-
FROST automatically defrosts roast beef, etc.. Touch the
COMPU COOK pad and number pad to select menu and
enter the food weight  by touching the number pads. When
the START pad is touched, the oven will cook according to
the special cooking sequence. 
						

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2. HORIZONTAL VENTING
The air handing is the same as VERTICAL VENTING
except that the final air discharge is directed horizontally
out from the top rear of the oven into the customers vent
system.
_: AIR FLOW
3. RE-CIRCULATION (INSIDE VENTING)
The air handing is the same as VERTICAL VENTING
except that the final air discharge is directed horizontally
through  the upper front of the oven into the kitchen. IN
this case, the accessory charcoal filter RK-230 must be
provided to filter the air before it leaves the oven.
_: AIR FLOW
VENTILATION METHODS HOT AIR EXHAUST
1. VERTICAL VENTING
For this venting method, hot air rising from the
conventional range below is drawn in by the hood fan
motor through the grease filters at the right and left sides
of the base cover, up through the right and left sides of
the oven cavity, then discharged vertically at rear center
top of the oven, into the customers vent system.
_: AIR FLOW
GREASE 
FILTER

 HOOD FAN MOTORTO DUCT
TO DUCT
HOOD 
INTAKE 
DUCT 
HOOD 
INTAKE 
DUCT  HOOD FAN MOTOR
GREASE 
FILTER

TO DUCT
HOOD 
INTAKE 
DUCT  HOOD EXHAUST 
LOUVER
HOOD FAN MOTORCHARCOAL 
FILTER