Sharp R-354M (serv.man4) Service Manual ▷ View online
R354M - 9
The touch control section consists of the following
units.
units.
(1) Key Unit (The key unit consists of a FPC
membrane and a Graphic sheet.)
(2) Control Unit (The Control Unit consists of
Power Unit and CPU Unit).
The principal functions of these units and the
signals communicated among them are
explained below.
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.
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, ACL circuit, indicator
circuit, power source circuit, relay circuit, buzzer
circuit, synchronizing signal circuit and back light
circuit.
Control unit consists of LSI, ACL circuit, indicator
circuit, power source circuit, relay circuit, buzzer
circuit, synchronizing signal circuit and back light
circuit.
1) ACL
This circuit generates a signal which resets the
LSI to the initial state when power is supplied.
LSI to the initial state when power is supplied.
2) Indicator Circuit
This circuit consists of 4-digits, 12-segments
and 3 common electrodes using a Liquid Crystal
Display.
and 3 common electrodes using a Liquid Crystal
Display.
G
HIGH VOLTAGE RECTIFIER TEST
CARRY OUT 3D CHECKS.
Isolate the high voltage rectifier assembly from the HV circuit. The high voltage rectifier can
be tested using an ohmmeter set to its highest range. Connect the ohmmeter across the
terminal of the high voltage rectifier and note the reading obtained. Reverse the meter leads
and note this second reading.
The normal resistance is infinite in one direction and more than 100 k
be tested using an ohmmeter set to its highest range. Connect the ohmmeter across the
terminal of the high voltage rectifier and note the reading obtained. Reverse the meter leads
and note this second reading.
The normal resistance is infinite in one direction and more than 100 k
Ω
in the other direction.
CARRY OUT 4R CHECKS.
NOTE:
FOR MEASUREMENT OF THE RESISTANCE OF THE RECTIFIER, THE
BATTERIES OF THE MEASURING INSTRUMENT MUST HAVE A VOLTAGE AT
LEAST 6 VOLTS, BECAUSE OTHERWISE AN INFINITE RESISTANCE MIGHT BE
SHOWN IN BOTH DIRECTIONS.
BATTERIES OF THE MEASURING INSTRUMENT MUST HAVE A VOLTAGE AT
LEAST 6 VOLTS, BECAUSE OTHERWISE AN INFINITE RESISTANCE MIGHT BE
SHOWN IN BOTH DIRECTIONS.
TEST PROCEDURES (CONT'D)
3) Power Source Circuit
This circuit generates voltages necessary in 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.
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.
Symbol
Voltage
Application
VC
-5.2V
LSI(IC1)
4) Relay Circuit
A circuit to drive the magnetron, fan motor, turnta-
ble motor and light the oven lamp.
ble motor and light the oven lamp.
5) Buzzer Circuit
The buzzer is responsive to signals from the LSI to
emit audible sounds (key touch sound and com-
pletion sound).
emit audible sounds (key touch sound and com-
pletion sound).
6) Synchronizing Signal Circuit
The power source synchronizing signal is avail-
able in order to compose a basic standard time in
the clock circuit.
It accompanies a very small error because it works
on commercial frequency.
able in order to compose a basic standard time in
the clock circuit.
It accompanies a very small error because it works
on commercial frequency.
7) Stop Switch
A switch to “tell” the LSI if the door is open or
closed.
closed.
8) Back Light Circuit
A circuit to drive the back light (Light emitting
diodes LD1- LD5).
diodes LD1- LD5).
TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOUCH CONTROL PANEL
PROCEDURE
LETTER
COMPONENT TEST
R354M - 10
LSI(IXA028DR)
The I/O signal of the LSI(IXA083DR) are detailed in the following table.
Pin No.
Signal
I/O
Description
20.0 msec.
During cooking
H : GND
L : -5V
100P
H : GND
L : -5V
H : GND
L : -5V
70P
ON
ON
OFF
OFF
OFF
24 sec.
8 sec.
20.0 msec.
H : GND
L : -5V
A
B
0.12 sec.
2.4 sec.
H : GND
L : -5V
H : GND
L : -5V
DESCRIPTION OF LSI
1-2
VL2-VL1
IN
Power source voltage input terminal.
Standard voltage for LCD.
Standard voltage for LCD.
3-6
AN7-AN4
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 functions.
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 functions.
7-8
P63-P62
OUT
Terminal not used.
9
AN1
IN
To input signal which communicates the door open/close information to LSI.
Door close "H" level signal (0V). Door open "L" level signal (-5V).
Door close "H" level signal (0V). Door open "L" level signal (-5V).
10
P60
OUT
Terminal not used.
11-13
P57-P55
OUT
Terminal not used.
14
CNTR0
OUT
Signal to sound buzzer (2.0 kHz).
A: key touch sound.
B: Completion sound.
15
P53
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 and RY3 control
circuit.
To turn on and off shut off relay (RY1). The
square waveform voltage is delivered to
the RY1 driving circuit and RY3 control
circuit.
16
P52
OUT
Magnetron high-voltage circuit driving signal.
To turn on and off the cook relay (RY3).
The signals holds "L" level during micro-
wave cooking and "H" level while not cook-
ing. In other cooking modes (variable cook-
ing) the signal turns to "H" level and "L"
level in repetition according to the power
level.
To turn on and off the cook relay (RY3).
The signals holds "L" level during micro-
wave cooking and "H" level while not cook-
ing. In other cooking modes (variable cook-
ing) the signal turns to "H" level and "L"
level in repetition according to the power
level.
(ON and OFF times for other power level.)
17-18
P51-P50
OUT
Terminal not used.
19
P47
OUT
Terminal not used.
20
P46
IN
Signal 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.
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.
21
P45
IN
Signal similar to P46.
When either G11 line on key matrix is touched, a corresponding signal will be input
into P45.
When either G11 line on key matrix is touched, a corresponding signal will be input
into P45.
22
P44
IN
Signal similar to P46.
When either G10 line on key matrix is touched, a corresponding signal will be input
into P44.
When either G10 line on key matrix is touched, a corresponding signal will be input
into P44.
23
P43
IN
Signal similar to P46.
When either G9 line on key matrix is touched, a corresponding signal will be input
into P43.
When either G9 line on key matrix is touched, a corresponding signal will be input
into P43.
24
INT0
IN
Signal synchronized with commercial power source frequency.
This is the basic timing for time processing
of LSI.
This is the basic timing for time processing
of LSI.
25
P41
OUT
Terminal not used.
26
P40
IN
Connected to VC through the pull-down resistor R90.
27
RESET
IN
Auto clear terminal.
Signal is input to reset the LSI to the initial state when power is applied. Temporarily
set "L" level the moment power is applied, at this time the LSI is reset. Thereafter
set at "H" level.
Signal is input to reset the LSI to the initial state when power is applied. Temporarily
set "L" level the moment power is applied, at this time the LSI is reset. Thereafter
set at "H" level.
R354M - 11
Pin No.
Signal
I/O
Description
LSI(IXA028DR)
The I/O signal of the LSI(IXA083DR) are detailed in the following table.
DESCRIPTION OF LSI
28-29
P71-P70
OUT
Terminal not used.
30
XIN
IN
Internal clock oscillation frequency input setting.
The internal clock frequency is set by inserting the ceramic filter oscillation
circuit with respect to XOUT terminal.
The internal clock frequency is set by inserting the ceramic filter oscillation
circuit with respect to XOUT terminal.
31
XOUT
OUT
Internal clock oscillation frequency control output.
Output to control oscillation input of XIN.
Output to control oscillation input of XIN.
32
VSS
IN
Power source voltage: -5.0V.
VC voltage of power source circuit input.
VC voltage of power source circuit input.
33
P27
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G1 line keys on key matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G1 line keys on key matrix is touched.
34
P26
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G2 line keys on key matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G2 line keys on key matrix is touched.
35
P25
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G3 line keys on key matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G3 line keys on key matrix is touched.
36
P24
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G4 line keys on key matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G4 line keys on key matrix is touched.
37
P23
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G5 line keys on key matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G5 line keys on key matrix is touched.
38
P22
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G6 line keys on key matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G6 line keys on key matrix is touched.
39
P21
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G7 line keys on key matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G7 line keys on key matrix is touched.
40
P20
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G8 line keys on key matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P43, P44, P45
and P46 terminal while one of G8 line keys on key matrix is touched.
41-56
P17-P00
OUT
Terminal not used.
57-60
P37-P34
OUT
Terminal not used.
61-72
SEG11-SEG0
OUT
Segment data signal.
Connected to LCD.
The relation between signals are as follows:
LSI signal (Pin No.) LCD segment
Connected to LCD.
The relation between signals are as follows:
LSI signal (Pin No.) LCD segment
LSI signal (Pin No.) LCD segment
SEG 11 (61) ............................ S12
SEG 5 (67) .............................. S6
SEG 10 (62) ............................ S11
SEG 4 (68) .............................. S5
SEG 9 (63) ............................ S10
SEG 3 (69) .............................. S4
SEG 8 (64) ............................ S9
SEG 2 (70) .............................. S3
SEG 7 (65) ............................ S8
SEG 1 (71) .............................. S2
SEG 6 (66) ............................ S7
SEG 0 (72) .............................. S1
73/74
VCC/VREF
IN
Connected to GND.
75
AVSS
IN
Connected to VC.
76
COM3
OUT
Terminal not used.
77
COM2
OUT
Common data signal.
Connected to LCD signal C3.
Connected to LCD signal C3.
78
COM1
OUT
Common data signal.
Connected to LCD signal C2.
Connected to LCD signal C2.
79
COM0
OUT
Common data signal.
Connected to LCD signal C1.
Connected to LCD signal C1.
80
VL3
IN
Power source voltage input terminal.
Standard voltage for LCD.
Standard voltage for LCD.
R354M - 12
SERVICING
TOUCH CONTROL PANEL ASSEMBLY
approx. 1M ohm
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
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 PW boards containing
them in aluminium foil.
them in aluminium foil.
2) When soldering, ground the technician as shown in
the figure and use grounded soldering iron and work
table.
table.
2. 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 SERV-
ICING AND PRESENTS A HAZARD .
THE HIGH VOLTAGE TRANSFORMER OF THE
MICROWAVE OVEN IS STILL LIVE DURING SERV-
ICING 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 transformer, 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 transformer, 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 between
the touch control panel and the oven itself is so
short that the two can't be separated.
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.
(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 so
long enough that they may be separated from each
other.
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
keeping it apart from the oven proper; in this case you
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 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 possible if the dummy resistor(s)
with resistance equal to that of the controls are
used.
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 possible 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. 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).
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. 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).
3. 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
4. Other Precautions
1) Before turning on the power source of the control
unit, remove the aluminium foil applied for
preventing static electricity.
preventing 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.
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