Sharp R-671M Service Manual ▷ View online
R-671M - 5
APPEARANCE VIEW
9. Door seals and sealing surfaces
10.Ventilation openings
11.Outer cabinet
12.Power supply cord
13.Turntable
14.Rack
10.Ventilation openings
11.Outer cabinet
12.Power supply cord
13.Turntable
14.Rack
1. Control panel
2. Oven lamp
3. Grill heating element (Top Grill)
4. Door opening button
5. Waveguide cover
6. Oven cavity
7. Turntable motor shaft
8. Grill heating element
2. Oven lamp
3. Grill heating element (Top Grill)
4. Door opening button
5. Waveguide cover
6. Oven cavity
7. Turntable motor shaft
8. Grill heating element
(Bottom Grill)
1. DIGITAL DISPLAY
2. COOKING MODE indicator lights
2. COOKING MODE indicator lights
These indicator lights will light during each cooking mode.
3. TIME keys
Use to enter cooking time.
4. BREAKFAST key
5. PIZZA key
6. INSTANT COOK keys
7. AUTO COOK key
5. PIZZA key
6. INSTANT COOK keys
7. AUTO COOK key
Press to select one of seven AUTO COOK menus.
8. AUTO DEFROST key
Press to select one of five AUTO DEFROST menus.
9. Kg.Lb/g.oz keys
Press to enter weight.
10. LESS/MORE keys
Press to shorten/ lengthen cooking time.
11. MICROWAVE POWER LEVEL key
Press to select microwave power level.
12. GRILL key
Press to select grill.
13. DUAL GRILL key
Press to select a combination of microwave with grill.
14. STOP/CLEAR key
Press once to stop programme, and/or twice to cancel a
programme.
programme.
15. START/AUTO MINUTE key
Press to start a programme. Press to cook on 100p (HIGH)
for 1 minute or increase time during cooking in multiples of
1 minute.
for 1 minute or increase time during cooking in multiples of
1 minute.
16. TIMER key
Press to use as a minute timer, or to programme standing
time.
time.
17. WEIGHT CONVERSION key
Use to alter weight until, e.g. Kg/g to Lb/oz.
18. AUTO START/CLOCK key
Use to set the clock or to programme AUTO START.
10min.
AUTO
COOK
AUTO
DEFROST
MICROWAVE
POWER LEVEL
STOP/
CLEAR
TIMER
Kg/Lb
AUTO START
CLOCK
START
AUTO MINUTE
Instant Cook
GRILL
LESS
MORE
Kg Lb g oz
DUAL
GRILL
1min.
10sec.
PIZZA
BREAKFAST
MIXED GRILL
OVEN CHIPS
BAKED POTATOES
1 Chilled Ready Meals
2 Frozen Ready meals
3 Roast Beef/Lamb
4 Roast Pork
5 Roast Poultry
6 Crispy Crumb Foods
7 Qulche / pie
2 Frozen Ready meals
3 Roast Beef/Lamb
4 Roast Pork
5 Roast Poultry
6 Crispy Crumb Foods
7 Qulche / pie
1 Meat Joint
2 Poultry
3 Chicken Portions/
2 Poultry
3 Chicken Portions/
Steak / Chops
4 Minced Meat
5 Bread
5 Bread
STR
AUTO
TOP GRILL
BOTTOM GRILL
BOTTOM GRILL
ADD KG PCS MICRO
MICRO
COOK
TURN
2
3
4
7
9
11
14
16
1
5
6
8
10
13
15
15
18
12
17
R-671M - 6
OPERATION SEQUENCE
OFF CONDITION
Closing the door activates the primary latch switch and the
stop switch.
stop switch.
IMPORTANT:
When the oven door is closed, the contacts COM-NC
of the monitor switch must be open. When the
microwave oven is plugged in a wall outlet (230-240V
50Hz), the line voltage is supplied to the noise filter.
When the oven door is closed, the contacts COM-NC
of the monitor switch must be open. When the
microwave oven is plugged in a wall outlet (230-240V
50Hz), the line voltage is supplied to the noise filter.
1. The control unit is not energized.
The display shows nothing. (Fig0-1a)
2. Open the door. The contacts (COM-NC) of the primary
latch switch are closed and the control unit is energized.
Then contacts of relays RY1 and RY6 are closed, the
oven lamp will light and the display will flash:
(Fig 0-1b).
Then contacts of relays RY1 and RY6 are closed, the
oven lamp will light and the display will flash:
(Fig 0-1b).
3. Close the door. The contacts (COM-NC) of the primary
latch switch are opened and the oven lamp will be
turned off. The display will stop flashing (Fig 0-1c).
turned off. The display will stop flashing (Fig 0-1c).
ENERGY SAVE MODE
NOTE 1. If the oven has not been used for more than two
minutes, the contacts of the relay RY6 will be
opened and the control unit will not be energized.
Open and close the door, the control unit will
resume.
opened and the control unit will not be energized.
Open and close the door, the control unit will
resume.
NOTE 2. If the clock is set, this energy save mode does
not work.
MICROWAVE COOKING CONDITION
HIGH COOKING
Enter a desired cooking time by pressing the TIME keys,
and select the power level by pressing the MICROWAVE
POWER LEVEL key and start the oven by pressing
START key.
and select the power level by pressing the MICROWAVE
POWER LEVEL key and start the oven by pressing
START key.
Function sequence Figure O-2 on page 30
CONNECTED COMPONENTS
RELAY
Oven lamp, Turntable motor
RY1
High voltage transformer
RY2
Grill heating element
RY3
Bottom heating element
RY4
Fan motor,
RY5
1. The line voltage is supplied to the primary winding of
the high voltage 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.
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 voltage doubling circuit, where it is doubled
to negative voltage of approximately 4000 volts D.C..
sent to the voltage doubling 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 channelled through the waveguide (transport
channel) into the oven cavity, where the food is placed
to be cooked.
energy is channelled 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 signal tone is heard and
the relays RY1 + RY2 + RY5 go back to their home
position. The circuits to the oven lamp, high voltage
transformer, fan motor and turntable motor are cut off.
position. The circuits to the oven lamp, high voltage
transformer, fan motor and turntable motor are cut off.
5. When the oven door is opened during a cooking cycle,
the switches come to the following condition.
Switch
Contact
Condition
During
During
Oven Door
Cooking
Open(No cooking)
Monitored latch Switch COM-NO
Closed
Opened
COM-NO
Opened
Closed
Stop switch
COM-NO
Closed
Opened
Monitor Switch
COM-NO
Closed
Opened
COM-NC
Opened
Closed
The circuit to the high voltage transformer, fan motor and
turntable motor are cut off when the monitored latch switch
and stop switch are made open. The oven lamp remains
on even if the oven door is opened after the cooking cycle
has been interrupted, because the relay RY1 stay closed.
Shown in the display is remaining time.
6. MONITOR SWITCH CIRCUIT
turntable motor are cut off when the monitored latch switch
and stop switch are made open. The oven lamp remains
on even if the oven door is opened after the cooking cycle
has been interrupted, because the relay RY1 stay closed.
Shown in the display is remaining time.
6. MONITOR SWITCH CIRCUIT
The monitor switch is mechanically controlled by the
oven door, and monitors the operation of the monitored
latch switch.
latch switch.
6-1. When the oven door is opened during or after the
cycle of a cooking program, the contacts (COM-NO)
of the monitored latch switch and stop switch must
open their contacts first. After that the contacts (COM-
NC) of the monitor switch can be closed.
of the monitored latch switch and stop switch must
open their contacts first. After that the contacts (COM-
NC) of the monitor switch can be closed.
6-2. When the oven door is closed, the contacts (COM-
NC) of the monitor switch must be opened. After that
the contacts (COM-NO) of the monitored latch switch
and the stop switch are closed.
the contacts (COM-NO) of the monitored latch switch
and the stop switch are closed.
6-3. When the oven door is opened and the contacts of the
monitored latch switch SW1 remain closed, the fuse
F8A will blow, because the monitor switch is closed
and a short circuit is caused.
F8A will blow, because the monitor switch is closed
and a short circuit is caused.
MEDIUM HIGH, MEDIUM, MEDIUM LOW, LOW
COOKING
COOKING
When the microwave oven is preset for variable cooking
power, the line voltage is supplied to the high voltage
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.
power, the line voltage is supplied to the high voltage
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
800P 100%
560P
70%
400P
50%
240P
30%
80P
10%
32 sec. ON
Approx. 100%
24 sec. ON
8 sec. OFF
Approx. 70%
18 sec. ON
14 sec. OFF
Approx. 50%
12 sec. ON
20 sec. OFF
Approx. 30%
6 sec. ON
26 sec. OFF
Approx. 10%
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.
approx. 3 seconds are needed for heating up the
magnetron filament.
GRILL COOKING CONDITION
The oven has three grill cooking condition. They are the
TOP GRILL mode, BOTTOM GRILL mode and TOP AND
BOTTOM GRILL mode.
TOP GRILL mode, BOTTOM GRILL mode and TOP AND
BOTTOM GRILL mode.
R-671M - 7
In this mode, the food is cooked by the grill heating
element (top grill). Enter the cooking time by pressing the
TIME keys and select the TOP GRILL mode by pressing
the GRILL key once. When the START button is pressed,
the following operations occur:
element (top grill). Enter the cooking time by pressing the
TIME keys and select the TOP GRILL mode by pressing
the GRILL key once. When the START button is pressed,
the following operations occur:
Figure O-3(a) on page 30
1. The relay RY1 + RY3 + RY5 are energized.
2. The numbers of the digital readout start the count down
2. The numbers of the digital readout start the count down
to zero.
3. Then the grill heating element (top), turntable motor,
oven lamp and fan motor are energized.
4. Now, the food is grilled by the grill heating element.
5. Upon completion of the selected cooking time, audible
5. Upon completion of the selected cooking time, audible
signal sounds and the contacts of relays RY1 + RY3
are opened, then the grill heating element (top), turntable
motor and oven lamp are de-energized.
are opened, then the grill heating element (top), turntable
motor and oven lamp are de-energized.
6. The relay RY5 stays closed for five (5) minutes, and the
fan motor operates.
BOTTOM GRILL MODE
In this mode, the food is cooked by the bottom heating
element. Enter the cooking time by pressing the TIME
keys and select the BOTTOM GRILL mode by pressing
the GRILL key twice. When the START key is pressed, the
following operations occur:
element. Enter the cooking time by pressing the TIME
keys and select the BOTTOM GRILL mode by pressing
the GRILL key twice. When the START key is pressed, the
following operations occur:
Figure O-3(b) on page 31
1. The relay RY1 + RY4 + RY5 are energized.
2. The numbers of the digital readout start the count down
2. The numbers of the digital readout start the count down
to zero.
3. Then the bottom heating element, turntable motor,
oven lamp and fan motor are energized.
4. Now, the food is grilled by the bottom heating element.
5. Upon completion of the selected cooking time, audible
5. Upon completion of the selected cooking time, audible
signal sounds and the contacts of relays RY1 + RY4
are opened, then the bottom heating element, turntable
motor and oven lamp are de-energized.
are opened, then the bottom heating element, turntable
motor and oven lamp are de-energized.
6. The relay RY5 stays closed for five (5) minutes, and the
fan motor operates.
TOP AND BOTTOM GRILL MODE
In this mode, the food is cooked by both the grill heating
element (top grill) and bottom heating element. Enter the
cooking time by pressing the TIME keys and select the
TOP AND BOTTOM GRILL mode by pressing the GRILL
key three times. When the START key is pressed, the
following operations occur:
element (top grill) and bottom heating element. Enter the
cooking time by pressing the TIME keys and select the
TOP AND BOTTOM GRILL mode by pressing the GRILL
key three times. When the START key is pressed, the
following operations occur:
Figure O-3(c) on page 31
1. The relay RY1 + RY3 + RY4 + RY5 are energized.
2. The numbers of the digital readout start the count down
2. The numbers of the digital readout start the count down
to zero.
3. Then the grill heating element (top), bottom heating
element, turntable motor, oven lamp and fan motor are
energized.
energized.
4. Now, the food is grilled by the grill heating element (top)
and the bottom heating element.
5. Upon completion of the selected cooking time, audible
signal sounds and the contacts of relays RY1 + RY3 +
RY4 are opened, then the grill heating element (top),
bottom heating element, turntable motor and oven
RY4 are opened, then the grill heating element (top),
bottom heating element, turntable motor and oven
lamp are de-energized.
6. The relay RY5 stays closed for five (5) minutes, and the
fan motor operates.
DUAL COOKING CONDITION
The oven has two dual cooking mode. One is MICROWAVE
AND TOP GRILL mode and the other one is MICROWAVE
AND BOTTOM GRILL mode. In both modes, the relay
RY2 operates intermittently with in a 48 seconds time base
as shown below.
AND TOP GRILL mode and the other one is MICROWAVE
AND BOTTOM GRILL mode. In both modes, the relay
RY2 operates intermittently with in a 48 seconds time base
as shown below.
Power level
ON time
OFF time
100%
48 sec.
0 sec.
70%
36 sec.
12 sec
50%
26 sec.
22 sec.
30%
16 sec.
32 sec
10%
8 sec.
40 sec
MICROWAVE AND TOP GRILL MODE
FIGURE 0-4(a) ON PAGE 32
In this mode, the food is cooked by microwave and the grill
heating element (top). Enter the cooking time by pressing
the TIME keys and select the MICROWAVE AND TOP
GRILL mode by pressing the DUAL GRILL cooking key
once. And select the power level by pressing the
MICROWAVE POWER LEVEL key. When the START
key is pressed, the following operations occur(Fig 0-4a):
1. The relay RY1 + RY2 + RY3 + RY5 are energized.
2. The numbers of the digital readout start the count down
heating element (top). Enter the cooking time by pressing
the TIME keys and select the MICROWAVE AND TOP
GRILL mode by pressing the DUAL GRILL cooking key
once. And select the power level by pressing the
MICROWAVE POWER LEVEL key. When the START
key is pressed, the following operations occur(Fig 0-4a):
1. The relay RY1 + RY2 + RY3 + RY5 are energized.
2. The numbers of the digital readout start the count down
to zero.
3. The grill heating element (top), high voltage transformer,
turntable motor, oven lamp and fan motor are energized.
4. Now, the food is cooked by the microwave and grill
heating element (top).
5. Upon completion of the selected cooking time, audible
signal sounds and the contacts of relays RY1 + RY2 +
RY3 are opened, then the grill heating element (top),
high voltage transformer, turntable motor and oven
lamp are de-energized.
RY3 are opened, then the grill heating element (top),
high voltage transformer, turntable motor and oven
lamp are de-energized.
6. The relay RY5 stays closed for five (5) minutes, and the
fan motor operates.
MICROWAVE AND BOTTOM GRILL MODE
FIGURE 0-4(b) ON PAGE 32
In this mode, the food is cooked by microwave and the
bottom heating element. Enter the cooking time by pressing
the TIME keys and select the MICROWAVE AND BOTTOM
GRILL mode by pressing the DUAL GRILL cooking key
twice. And select the power level by pressing the
MICROWAVE POWER LEVEL key. When the START
key is pressed, the following operations occur(Fig 0-4b):
1. The relay RY1 + RY2 + RY4 + RY5 are energized.
2. The numbers of the digital readout start the count down
bottom heating element. Enter the cooking time by pressing
the TIME keys and select the MICROWAVE AND BOTTOM
GRILL mode by pressing the DUAL GRILL cooking key
twice. And select the power level by pressing the
MICROWAVE POWER LEVEL key. When the START
key is pressed, the following operations occur(Fig 0-4b):
1. The relay RY1 + RY2 + RY4 + RY5 are energized.
2. The numbers of the digital readout start the count down
to zero.
3. The bottom heating element, high voltage transformer,
turntable motor, oven lamp and fan motor are energized.
4. Now, the food is cooked by the microwave and bottom
heating element.
5. Upon completion of the selected cooking time, audible
signal sounds and the contacts of relays RY1 + RY2 +
RY4 are opened, then the bottom heating elements,
high voltage transformer, turntable motor and oven
lamp are de-energized.
RY4 are opened, then the bottom heating elements,
high voltage transformer, turntable motor and oven
lamp are de-energized.
TOP GRILL MODE
OPERATION SEQUENCE
CONT
...
R-671M - 8
6. The relay RY5 stays closed for five (5) minutes, and the
fan motor operates.
BREAKFAST COOKING
PIZZA COOKING
INSTANT COOKING
AUTO COOKING
AUTO DEFROST
PIZZA COOKING
INSTANT COOKING
AUTO COOKING
AUTO DEFROST
These functions automatically work out the correct cooking
mode and time for cooking/defrosting. The oven will cook
or defrost according to the special cooking/defrosting
sequence.
mode and time for cooking/defrosting. The oven will cook
or defrost according to the special cooking/defrosting
sequence.
LIMITATIONS OF POWER OUTPUT IN MANUAL
OPERATION
OPERATION
After the same cooking mode is carried out for more than
the specified cooking time, the power output is automatically
reduced by turning the control relays on and off
intermittently, as shown in the table below. This is to
protect the oven door against temperature rising.
the specified cooking time, the power output is automatically
reduced by turning the control relays on and off
intermittently, as shown in the table below. This is to
protect the oven door against temperature rising.
Specified cooking
Limited power
Time base
Cooking mode
time (minutes)
output (%)
(seconds)
Microwave (100%)
30
70
32
Top Grill
30
50
48
Bottom Grill
30
50
48
Top Grill and
10 (Top)
50
48
Bottom Grill
10 (Bottom)
50
48
Micro.(100%)
20 (Micro.)
70
48
+ Top Grill
15 (Grill)
50
48
Micro.(100%)
20 (Micro.)
70
48
+ Bottom Grill
15 (Heater)
50
48
NOTE:
1. In case of Automatic operations, the limitations of
power output are not carried out.
2. In case that the STOP key is pressed or the oven door
is opened during cooking, the limitations of power
output are not carried out after the total cooking time
beyond the specified cooking time.
output are not carried out after the total cooking time
beyond the specified cooking time.
3. In case of the two or more same cooking modes are
carried out, the limitations of power output are not
carried out after the total cooking time beyond the
specified cooking time.
carried out after the total cooking time beyond the
specified cooking time.
4. In case of the two or more different cooking modes are
carried out, the specified cooking time is started to
count from the point when the cooking mode is changed.
count from the point when the cooking mode is changed.
5. If the cooking mode has the power level display, the
power level is also displayed when the limitations of
power output are carried out.
power output are carried out.
D
U
A
L
STOP SWITCH
1. When the oven door is closed, the contacts (COM-NO)
of the switch must be closed.
2. When the oven door is opened, the contacts (COM-
NO) of the switch must be opened.
MONITORED LATCH SWITCH
1. When the oven door is closed, the contacts (COM-NO)
of the switch must be closed and the contacts (COM-
NC) must be opened.
NC) must be opened.
2. When the oven door is opened, the contacts (COM-
NO) of the switch must be opened and the contacts
(COM-NC) must be closed.
(COM-NC) must be closed.
MONITOR SWITCH
1. When the door is closed, the contacts (COM-NC) must
be opened and the contacts (COM-NO) must be
closed.
closed.
2. When the door is opened, the contacts (COM-NC)
must be closed and the contacts (COM-NO) must be
closed.
closed.
3. If the oven door is opened and the contacts (COM-NO)
of the monitored latch switch fail to open, the fuse F8A
blows immediately after closing the contacts (COM-
NC) of the monitor switch.
blows immediately after closing the contacts (COM-
NC) of the monitor switch.
CAUTION: BEFORE REPLACING A BLOWN FUSE F8A,
TEST THE MONITORED LATCH SWITCH,
MONITOR SWITCH. FOR PROPER
OPERATION. (REFER TO CHAPTER “TEST
PROCEDURE”).
MONITOR SWITCH. FOR PROPER
OPERATION. (REFER TO CHAPTER “TEST
PROCEDURE”).
SPECIAL FUSE 15A
If the wire harness or electrical components are short-
circuited, this fuse blows to prevent an electric shock of fire
hazard.
circuited, this fuse blows to prevent an electric shock of fire
hazard.
FUSE F8A 250V
1. If the wire harness or electrical components are short-
circuited, this fuse blows to prevent an electric shock of
fire hazard.
fire hazard.
2. The fuse also blows when the primary (monitored)
latch switch remains closed with the oven door open
and when the monitor switch contact (COM-NC) closes.
and when the monitor switch contact (COM-NC) closes.
FUNCTION OF IMPORTANT COMPONENTS
OPERATION SEQUENCE
CONT
...
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