Sharp R-641AM Service Manual ▷ View online
9
R-641M -
17
XRESET
IN
Auto clear terminal.
Signal is input to reset the LSI to the initial state when power is supplied.
Temporarily set "L" level the moment power is supplied, at this time the LSI
is reset. Thereafter set at "H" level.
Temporarily set "L" level the moment power is supplied, at this time the LSI
is reset. Thereafter set at "H" level.
18
XTEST
IN
Connected to GND.
19
VSS
IN
Power source voltage: -5V.
Power source voltage is applied to drive the LSI.
20
OSC1
IN
Internal clock oscillation frequency setting input.
The internal clock frequency is set by inserting the ceramic filter oscillation
circuit with respect to OSC2 terminal.
circuit with respect to OSC2 terminal.
21
OSC2
OUT
Internal clock oscillation frequency control output.
Output to control oscillation input of OSC1.
22
VD1
IN
Power source voltage input terminal.
Power source voltage is applied to drive the oscillation circuit which makes
the clock signal in the LSI.
the clock signal in the LSI.
23
VDD
IN
Power source voltage: 0V.
Power source voltage is applied to drive the LSI.
24
AVDD
IN
Power source voltage input terminal.
Power source voltage is applied to drive the A/D converter in the LSI.
Connected to GND.
Connected to GND.
25
AVREF
IN
Reference voltage input terminal.
A reference voltage is applied to drive the A/D converter in the LSI.
Connected to GND.
Connected to GND.
26
AVSS
IN
Power source voltage input terminal.
Power source voltage is applied to drive the A/D converter in the LSI.
Connected to VC. (-5V)
Connected to VC. (-5V)
27-28
NC
No connection terminal.
29-32
R40-R43
IN
Terminal to change functions 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 function.
with the Model in operation is applied to set up its function.
33
NC
No connection terminal.
TOUCH CONTROL
Pin No.
Signal
I/O
Description
34
BZ
OUT
Signal to sound buzzer (2.0 kHz).
A: key touch sound.
B: Completion sound.
35
R00
OUT
Terminal not used.
36
R01
OUT
Grill heating element driving signal.
To turn on and off the grill heating
element relay (RY2). "L" level during
grill cooking or dual cooking; "H" level
otherwise.
element relay (RY2). "L" level during
grill cooking or dual cooking; "H" level
otherwise.
37
R02
OUT
Magnetron high-voltage circuit driving signal.
To turn on and off the cook
relay (RY3). In 100% POWER
operation, the signals hold
"L" level during microwave
cooking and "H" level while
not cooking. In other cooking
modes (70%, 50%, 30%, 10%)
the signal turns to "H" level
and "L" level in repetition
according to the power level.
relay (RY3). In 100% POWER
operation, the signals hold
"L" level during microwave
cooking and "H" level while
not cooking. In other cooking
modes (70%, 50%, 30%, 10%)
the signal turns to "H" level
and "L" level in repetition
according to the power level.
ON/OFF time ratio in Mi-
cro cooking
(a. 32second time base)
cro cooking
(a. 32second time base)
ON/OFF time ratio in Mi-
cro cooking
(a. 48second time base)
cro cooking
(a. 48second time base)
MICRO
ON
OFF
COOK
100%
100%
32sec.
0sec.
70%
24sec.
8sec.
50%
18sec.
14sec.
30%
12sec.
20sec.
10%
6sec.
26sec.
MICRO
ON
OFF
COOK
100%
48sec.
0sec.
70%
36sec.
12sec.
50%
26sec.
22sec.
30%
16sec.
32sec.
10%
8sec.
40sec.
A
B
0.1 sec.
2 sec.
H : 0V
L: -5V
H : 0V
L: -5V
(Grill or dual)
ON
OFF
During
cooking
L : -5V
0V
H :
10
R-641M -
Pin No.
Signal
I/O
Description
38
R03
OUT
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.
(RY1). The square waveform voltage
is delivered to the RY1 driving circuit.
39
P20
IN
Signal coming from tact switch.
When either of tact switches SW64-SW66 is touched, a corresponding
signal out of SEG1, SEG2 and SEG3 will be input into P20. When no tact
switch is touched, the signal is held at "H" level.
signal out of SEG1, SEG2 and SEG3 will be input into P20. When no tact
switch is touched, the signal is held at "H" level.
40-41
P21-P22
OUT
Terminal not used.
42
P23
IN
Signal coming from tact switch.
When either of tact switches SW60-SW62 is touched, a corresponding
signal out of SEG0, SEG1, SEG2 and SEG3 will be input into P23. When no
tact switch is touched, the signal is held at "H" level.
signal out of SEG0, SEG1, SEG2 and SEG3 will be input into P23. When no
tact switch is touched, the signal is held at "H" level.
43
INT0
IN
Signal synchronized with commercial power source frequency.
This is the basic timing for time
processing of LSI.
processing of LSI.
44
INT1
IN
Connected to VC. (-5V)
45
K02
IN
Connected to VC. (-5V)
46
K03
IN
To input signal which communicates the door open/close information to
LSI.
LSI.
Door open "L" level signal (-5V). Door close "H" level (0V)
47
COM0
OUT
Common data signal: COM0.
Connected to LCD. (C1)
48
COM1
OUT
Common data signal: COM1.
Connected to LCD. (C2)
49
COM2
OUT
Common data signal: COM2.
Connected to LCD. (C3)
50
COM3
OUT
Terminal not used.
51
SEG0
OUT
Tact switch strobe signal.
Signal applied to tact switch section. A pulse signal is input to P23 terminal
while the tact switch SW60 is touched.
while the tact switch SW60 is touched.
52
SEG1
OUT
Tact switch strobe signal.
Signal applied to tact switch section. A pulse signal is input to P23 terminal
while the tact switch SW61 is touched.
while the tact switch SW61 is touched.
53
SEG2
OUT
Tact switch strobe signal.
Signal applied to tact switch section. A pulse signal is input to P23 terminal
while the tact switch SW63 or SW65 is touched. A pulse signal is input to
P20 terminal while the tact switch SW65 is touched.
while the tact switch SW63 or SW65 is touched. A pulse signal is input to
P20 terminal while the tact switch SW65 is touched.
54
SEG3
OUT
Tact switch strobe signal.
Signal applied to tact switch section. A pulse signal is input to P23 terminal
while the tact switch SW62 is touched. A pulse signal is input to P20 terminal
while the tact switch SW66 is touched.
while the tact switch SW62 is touched. A pulse signal is input to P20 terminal
while the tact switch SW66 is touched.
55-58
SEG4-
OUT
Terminal not used.
SEG7
59-63
SEG8-
OUT
Segment data signal.
SEG12
Signal is similar to SEG13. Connected to LCD.
64
NC
No connection terminal.
TOUCH CONTROL
20.0 msec
H : 0V
L : -5V
(Grill or dual)
ON
OFF
During
cooking
L : -5V
0V
H :
11
R-641M -
TOUCH CONTROL
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.
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 be-
tween the touch control panel and the oven
proper is so long enough that they may be
separated from each other. For those models,
therefore, it is possible to check and repair the
controls of the touch control panel while keep-
ing 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 brings about 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 pos-
sible if the dummy resistor(s) with resistance
equal to that of the controls are used.
proper is so long enough that they may be
separated from each other. For those models,
therefore, it is possible to check and repair the
controls of the touch control panel while keep-
ing 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 brings about 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 pos-
sible if the 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 brings about an operational state that
is equivalent to the oven door being closed. Con-
nect 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).
from the oven proper, and short both ends of the
door sensing switch (on PWB) of the touch control
panel, which brings about an operational state that
is equivalent to the oven door being closed. Con-
nect 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
assembly.
1) Soldering iron: 30W
(It is recommended to use a soldering iron with a
grounding terminal.)
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 pre-
venting static electricity.
venting static electricity.
2) Connect the connector 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.
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.
E
C
B
Transistor
2SB1238
2SB1238
E
C B
Transistor
DTA123ES
DTA143ES
DTB143ES
DTD143ES
DTA123ES
DTA143ES
DTB143ES
DTD143ES
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 influ-
enced by the surrounding high voltage power source,
static electricity charge in clothes, etc., and some-
times it is not fully protected by the built-in protection
circuit.
In order to protect CMOS LSI.
1) When storing and transporting, thoroughly wrap
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 influ-
enced by the surrounding high voltage power source,
static electricity charge in clothes, etc., and some-
times 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 PW boards
containing them in aluminium foil.
containing them in aluminium foil.
2) When soldering, ground the technician as shown
in the figure and use grounded soldering iron and
work table.
work table.
approx. 1M ohm
2. Shapes of Electronic Components
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.
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 .
THE HIGH VOLTAGE TRANSFORMER OF THE
MICROWAVE OVEN IS STILL LIVE DURING
SERVICING AND PRESENTS A HAZARD .
Therefore, when checking the performance of the
touch control panel, put the outer cabinet on the
oven to avoid touching the high voltage trans-
former, or unplug the primary terminal (connector)
of the high voltage transformer to turn it off; the end
of such connector must be insulated with an
insulating tape. After servicing, be sure to replace
the leads to their original locations.
touch control panel, put the outer cabinet on the
oven to avoid touching the high voltage trans-
former, or unplug the primary terminal (connector)
of the high voltage transformer to turn it off; the end
of such connector must be insulated with an
insulating tape. After servicing, be sure to replace
the leads to their original locations.
A.
On some models, the power supply cord be-
tween the touch control panel and the oven
itself is so short that the two can't be separated.
itself is so short that the two can't be separated.
SERVICING
12
R-641M -
COMPONENT REPLACEMENT
DOOR ASSEMBLY
OUTER CASE
CABINET
CABINET
LATCH HEADS
Door Assembly Replacement and Adjustment
LATCH HEAD REMOVAL
1.
Remove the choke as described in door
replacement.
replacement.
2.
Unhook the spring and lift the latch head clear.
3.
Replacement, the reverse of the above.
MONITORED LATCH SWITCH, LATCH
SWITCH, AND MONITOR SWITCH REMOVAL
SWITCH, AND MONITOR SWITCH REMOVAL
1.
CARRY OUT 3D CHECKS.
2.
Disconnect the leads from all switches.
3.
Remove the one (1) screw holding the latch hook to the
oven cavity.
oven cavity.
4.
Remove the latch hook.
5.
Push the retaining tab slightly and remove the switch.
OUTER DOOR FILM
Removal
1. Remove the door film from the clips on the door
frame.
Installation
1. Attach the door film to the clips on the door frame.
DOOR FILM
BACKING FILM
Switches
LATCH HOOK
SW3: STOP
SWITCH
SWITCH
SW1: MONITORED
LATCH SWITCH
LATCH SWITCH
SW2: MONITOR
SWITCH
SWITCH
Tab
Post
Tab
Tab
Post
Post
DOOR REPLACEMENT
1.
CARRY OUT 3D CHECKS.
2.
Remove choke cover taking care not to break
clips by inserting an iron plate (thickness of about
0.5mm) or flat type screw driver into the gap between
the choke cover and door panel to free the engaged
part.
clips by inserting an iron plate (thickness of about
0.5mm) or flat type screw driver into the gap between
the choke cover and door panel to free the engaged
part.
3.
Remove door assembly by lifting and easing
it forward.
it forward.
4.
On re-installation make sure the door is
parallel with the bottom line of the oven face
plate and the latch head pass through the
latch holes correctly.
parallel with the bottom line of the oven face
plate and the latch head pass through the
latch holes correctly.
5.
CARRY OUT 4R CHECKS.
NOTE : After any service to the door, the
approved microwave survey meter should be
used to assure in compliance with proper
microwave radiation standards.
used to assure in compliance with proper
microwave radiation standards.
INNER DOOR FILM
Removal
1.
1.
Tear the door film from the door panel.
2.
Now the door film is free.
Installation
1.
1.
Tear away the backing film.
2.
Put the pasted side of the door film on the door
panel
panel
.
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