DOWNLOAD Sharp R-341AM Service Manual ↓ Size: 577.99 KB | Pages: 24 in PDF or view online for FREE

Model
R-341AM
Pages
24
Size
577.99 KB
Type
PDF
Document
Service Manual
Brand
Device
Home Appliance / Microwave Oven
File
r-341am.pdf
Date

Sharp R-341AM Service Manual ▷ View online

R341M - 1
XXXXXXXXXXXXX
MICROWAVE OVEN
In interests of user-safety the oven should be restored to its original
condition and only parts identical to those specified should be used.
SHARP CORPORATION
SERVICE MANUAL
TABLE OF CONTENTS
Page
SERVICING ................................................................................................................................................ X
CAUTION / WARNING ............................................................................................................................... X
PRODUCT DESCRIPTION ......................................................................................................................... X
OPERATION DATA .................................................................................................................................... X
OUTPUT POWER TEST PROCEDURE .................................................................................................... X
IMPORTANT COMPONENTS .................................................................................................................... X
TEST PROCEDURES ................................................................................................................................ X
TOUCH CONTROL PANEL ASSEMBLY ................................................................................................. XX
COMPONENT PLACEMENT AND ADJUSTMENT .................................................................................. XX
WIRING / RE-WIRING .............................................................................................................................. XX
SCHEMATIC DIAGRAM ........................................................................................................................... XX
WIRING DIAGRAM ................................................................................................................................... XX
PART LIST ................................................................................................................................................ XX
EXPLODED ILLUSTRATION .................................................................................................................... XX
PACKING AND ACCESSORIES .............................................................................................................. XX
MODEL
R-341(W)M
R-341(G)M
R341M - 2
High voltage capacitor, High voltage transformer, Magnetron, High voltage rectifier assembly, High voltage
harness.
REMEMBER TO CHECK 3D
1) Disconnect the supply.
2) Door opened, and wedged open.
3) Discharge high voltage capacitor.
WARNING AGAINST THE CHARGE OF THE HIGH-VOLTAGE CAPACITOR
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, of the connecting lead of the
high-voltage rectifier) against the chassis using a screwdriver with an insulated handle.
Microwave ovens should not be used without a load.   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 microwave timer for one (1) minute, set the
power level to HIGH (100%) and push the start key. When the one (1) minute has elapsed (timer at zero) carefully check
that the water is now hot.
AFTER REPAIR REMEMBER TO CHECK 4R
1) Reconnect all leads removed from components during testing.
2) Replace the outer case (cabinet).
3) Reconnect the supply.
4) Run the oven. Check all functions.
When all service work is completed, and the oven is fully assembled, the microwave power output should be checked
and microwave leakage test carried out.
IMPORTANT:
If the oven becomes inoperative because of a blown fuse M8A in the 1st latch switch - monitor switch
circuit, check the 1st latch switch and monitor switch before replacing the fuse M8A.
Sharp recommend that wherever possible, fault-finding is carried out with the supply disconnected.  In some
cases, it may be necessary to connect the supply with  the cover removed to carry out fault investigation in the
control circuitry.  In such cases, the high voltage circuit should be disabled as described below to reduce the
hazards:-
Carry out 3D checks (see above).
Disconnect the supply leads from the high voltage transformer, making a note of the polarity.  Insulate the
connectors, ensuring they are positioned away from the transformer and fastened there.
Connect any relevant test equipment e.g. voltmeter.
Reconnect the oven to the supply, then close the door.
Note the results of the test, taking care to keep clear of the operational oven.
Carry out 3D checks (see above).
Reconnect the leads to the transformer.  Take care to observe correct polarity.
Carry out 4R checks (see below).
 WARNING TO SERVICE PERSONNEL
Microwave ovens contain circuitry capable of producing very high voltage and current. Contact with following parts
will result in electrocution:-
SERVICING
R341M - 3
WARNING
Servicing and repair work must be carried out only by
trained service engineers.
The parts marked '*' on the parts list and schematic
diagram have voltages in excess of 250V.
Removal of the outer wrap gives access to potential
above 250V.
All the parts marked "
" on the parts list may cause undue
microwave exposure, by themselves, or when they are
damaged, loosened or removed.
CAUTION
MICROWAVE RADIATION
Do not become exposed to radiation from the
magnetron or other parts conducting microwave
energy.  All input and output microwave
connections, waveguides, flanges and gaskets must
be secured. Never operate the device without a
microwave energy absorbing load attached. Never
look into an open waveguide or antenna while the
device is energized.
WARNING
THIS APPLIANCE MUST BE EARTHED
THE WIRES IN THIS MAINS LEAD ARE COLOURED IN
ACCORDANCE WITH THE FOLLOWING CODE:
GREEN-AND-YELLOW : EARTH        BLUE : NEUTRAL        BROWN : LIVE
If the mains lead is replaced, only part number QACCBA032WRE3 should be used
SPECIFICATION
Power Requirements
230 -240 Volts     50 Hertz     Single phase, 3 wire earthed
Power Consumption
1.45kW
Power Output
900  watts nominal of RF microwave energy
(measured by way of IEC 705)
Operating frequency of 2450 MHz
Case Dimensions
Width 520 mm     Height 305 mm including foot     Depth 413 mm
Cooking Cavity Dimensions
Width 342 mm     Height 207 mm     Depth 368 mm
Turntable diameter
325 mm
Control Complement
Simple Touch Control System
Clock (1.00 - 12.59 or 0.00 - 23.59)
Microwave Power for Variable Cooking
Repetition Rate:
HIGH
 Full power throughout the cooking time
MEDIUM HIGH
 approx. 70% of FULL Power
MEDIUM
 approx. 50% of FULL Power
MEDIUM LOW
 approx. 30% of FULL Power
LOW
 approx. 10% of FULL Power
START/AUTO MINUTE pad
AUTO COOK/DEFROST pad
POWER LEVEL/WEIGHT pad
MORE/LESS pads
STOP/CLEAR pad
Time pads
Set Weight
Approx. 17 kg
 
   PRODUCT DESCRIPTION
CAUTION / WARNING
R341M - 4
OPERATION DATA
CONNECTED COMPONENTS
RELAY
Oven lamp, Fan motor, Turntable motor
RY1
Power transformer
RY2
Approx. 10% = 90 Watts
32 sec. ON
6 sec. ON
12 sec. ON
18 sec. ON
24 sec. ON
30 sec. OFF
20 sec. OFF
14 sec. OFF
8 sec. OFF
LOW
MEDIUM HIGH
MEDIUM
MEDIUM LOW
HIGH
Approx. 70% = 630 Watts
Approx. 50% = 450 Watts
Approx. 30% = 270 Watts
OFF CONDITION
Closing the door activates all door interlock switches (latch
switch, monitored latch switch and stop switch).
IMPORTANT
When the oven door is closed, the monitor switch contacts
COM - NC must be open.
When the microwave oven is pluged in a wall outlet (230 -
240V 50Hz), the line voltage is supplied to the point A3+A5
in the control unit.
1. The display flashes ”88:88”.
2. To set any programmes or set the clock, you must first
touch the STOP pad.
3. “  :  ” appears in the display.
MICROWAVE COOKING CONDITION
HIGH COOKING
Enter a desired cooking time by touching the Time pads and
start the oven by touching the START pad.
1. The line voltage is supplied to the primary winding of the
power transformer. The voltage is converted to about
3.3 volts A.C. output on the filament winding and high
voltage of approximately 2000 volts A.C. on the
secondary winding.
2. The filament winding voltage (3.3 volts) heats the
magnetron filament and the high voltage (2000 volts) is
sent to the voltagedoubling circuit, where it is doubled to
negative voltage of approximately 4000 volts D.C..
3. The 2450 MHz microwave energy produced in the
magnetron generates a wave length of 12.24 cm. This
energy is channeled through the waveguide (transport
channel) into the oven cavity, where the food is placed
to be cooked.
4. When the cooking time is up, a single tone is heard and
the relays RY1 + RY2 go back to their home position.
The circuits to the oven lamp, power transformer, fan
motor and turntable motor are cut off.
5. When the door is opened during a cook cycle, the
switches come to the following condition.
The circuits to the power transformer,oven lamp fan
motor and turntable motor are cut off when the monitored
latch switch and stop switch are made open.   Shown in
the display is the remaining time.
6. MONITOR SWITCH CIRCUIT
The monitor switch (SW2) is mechanically controlled by
oven door, and monitors the operation of the monitored
latch switch (SW1)
6-1
When the oven door is opened during or after the
cycle of cooking program, the monitored latch switch
(SW1), and stop switch (SW3) must open their contacts
first. After that the contacts (COM - NC) of the monitor
switch (SW2) can be closed.
6-2
When the oven door is closed, the contacts
(COM - NC) of the monitor switch (SW2) must be
opened first.  After that the contacts of the monitored
latch switch (SW1) and stop switch (SW3) are closed.
6-3
When the oven door is opened and the contacts of the
monitored latch switch (SW1) remain closed, the fuse
(F1) F8A will blow, because the monitor switch is
closed and a short circuit is caused.
MEDIUM HIGH, MEDIUM, MEDIUM LOW, LOW
COOKING
When the microwave oven is preset for variable cooking
power, the line voltage is supplied to the power transformer
intermittently within a 32-second time base through the
relay contact which is coupled with the current-limiting relay
(RY2). The following levels of microwave power are given.
SETTING
CONDITION
DURING
DOOR OPEN
SWITCH
CONTACT
COOKING
(NO COOKING)
Monitored latch switch
COM-NO
Closed
Open
Monitor switch
COM-NC
Open
Closed
Stop switch
COM-NO
Closed
Open
Monitor switch
COM-NO
Closed
Open
NOTE: The ON/OFF time ratio does not exactly correspond
to the percentage of microwave power, because
approx. 3 seconds are needed for heating up the
magnetron filament.
100% = 900 Watts
Page of 24
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  • DOWNLOAD Sharp R-341AM Service Manual ↓ Size: 577.99 KB | Pages: 24 in PDF or view online for FREE
  • Here you can View online or download the Service Manual for the Sharp R-341AM in PDF for free, which will help you to disassemble, recover, fix and repair Sharp R-341AM Microwave Oven. Information contained in Sharp R-341AM Service Manual (repair manual) includes:
  • Disassembly, troubleshooting, maintenance, adjustment, installation and setup instructions.
  • Schematics, Circuit, Wiring and Block diagrams.
  • Printed wiring boards (PWB) and printed circuit boards (PCB).
  • Exploded View and Parts List.