Sharp R-33ST Service Manual ▷ View online
R33ST - 11
Pin No.
Signal
I/O
Description
32
P72
OUT
Terminal not used.
33
P71
IN
Terminal not used.
34
P70
IN
Connected to VC.
35
RESET
IN
Auto clear terminal.
Signal is input to reset the LSI to the initial state when power is applied.
Temporarily set to "L" level the moment power is applied, at this time the LSI is
reset. Thereafter set at "H" level.
Temporarily set to "L" level the moment power is applied, at this time the LSI is
reset. Thereafter set at "H" level.
36
XCIN
IN
Terminal not used.
37
XCOUT
OUT
Terminal not used.
38
XIN
IN
Internal clock oscillation frequency input setting.
The internal clock frequency is set by inserting the ceramic filter oscillation circuit
with respect to XIN terminal.
with respect to XIN terminal.
39
XOUT
OUT
Internal clock oscillation frequency control output.
Output to control oscillation input of XOUT.
40
VSS
IN
Power source voltage: -5V.
VC voltage of power source circuit input.
41-44
P27-P24
IN/OUT
Terminal not used.
45
P23
IN
Signal coming from touch key.
When any one of G2 line keys on key matrix is touched, a corresponding signal
from P11 - P17 will be input into P23. When no key is touched, the signal is held
at "L" level.
from P11 - P17 will be input into P23. When no key is touched, the signal is held
at "L" level.
46
P22
IN
Signal similar to P23.
When any one of G5 and G9 line keys on key matrix is touched, a corresponding
signal will be input into P22.
signal will be input into P22.
47
P21
IN
Signal similar to P23.
When any one of G7 line keys on key matrix is touched, a corresponding signal
will be input into P21.
will be input into P21.
48
P20
IN
Signal similar to P23.
When any one of G11 line keys on key matrix is touched, a corresponding signal
will be input into P20.
will be input into P20.
49
P17
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P20 - P23 terminal
while one of G12 line keys on matrix is touched.
while one of G12 line keys on matrix is touched.
50
P16
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P20 - P23 terminal
while one of G10 line keys on matrix is touched.
while one of G10 line keys on matrix is touched.
51
P15
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P20 - P23 terminal
while one of G8 line keys on matrix is touched.
while one of G8 line keys on matrix is touched.
52
P14
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P20 - P23 terminal
while one of G6 line keys on matrix is touched.
while one of G6 line keys on matrix is touched.
53
P13
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P20 - P23 terminal
while one of G4 line keys on matrix is touched.
while one of G4 line keys on matrix is touched.
54
P12
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P20 - P23 terminal
while one of G3 line keys on matrix is touched.
while one of G3 line keys on matrix is touched.
55
P11
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P20 - P23 terminal
while one of G1 line keys on matrix is touched.
while one of G1 line keys on matrix is touched.
DESCRIPTION OF LSI
LSI(IZA988DR)
The I/O signal of the LSI(IZA988DR) are detailed in the following table.
R33ST - 12
Pin No.
Signal
I/O
Description
56
P10
OUT
Terminal not used.
57-60
SEG33-SEG30
OUT
Terminal not used.
61-90
SEG29-SEG0
OUT
Segment data signal.
Connected to LCD.
The relation between signals are as follows:
The relation between signals are as follows:
LSI signal (Pin No.) LCD (Pin No.) LSI signal (Pin No.) LCD (Pin No.)
SEG 0 (90) ............................... 1
SEG 0 (90) ............................... 1
SEG15 (75) ............................ 29
SEG 1 (89) ............................... 2
SEG16 (74) ............................ 28
SEG 2 (88) ............................... 3
SEG17 (73) ............................ 27
SEG 3 (87) ............................... 4
SEG18 (72) ............................ 26
SEG 4 (86) ............................... 5
SEG19 (71) ............................ 25
SEG 5 (85) ............................... 6
SEG20 (70) ............................ 24
SEG 6 (84) ............................... 7
SEG21 (69) ............................ 11
SEG 7 (83) ............................... 8
SEG22 (68) ............................ 23
SEG 8 (82) ............................... 9
SEG23 (67) ............................ 22
SEG 9 (81) ............................. 10
SEG24 (66) ............................ 12
SEG10 (80) ............................. 34
SEG25 (65) ............................ 13
SEG11 (79) ............................. 33
SEG26 (64) ............................ 14
SEG12 (78) ............................. 32
SEG27 (63) ............................ 15
SEG13 (77) ............................. 31
SEG28 (62) ............................ 16
SEG14 (76) ............................. 30
SEG29 (61) ............................ 17
91
VCC
IN
Connected to GND.
92
VREF
IN
Connected to GND.
93
AVSS
IN
Connected to VC.
94
COM3
OUT
Common data signal: COM3.
Connected to LCD (Pin No. 21).
95
COM2
OUT
Common data signal: COM2.
Connected to LCD (Pin No. 20).
96
COM1
OUT
Common data signal: COM1.
Connected to LCD (Pin No. 19).
97
COM0
OUT
Common data signal: COM0.
Connected to LCD (Pin No. 18).
98-99
VL3-VL2
IN
Power source voltage input terminal.
Standard voltage for LCD.
100
C2
IN
Terminal not used.
DESCRIPTION OF LSI
LSI(IZA988DR)
The I/O signal of the LSI(IZA988DR) are detailed in the following table.
R33ST - 13
SERVICING
controls (sensor-related ones included) of the touch
control panel while keeping it connected to the oven.
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.
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 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.
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 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.
(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).
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).
4. Servicing Tools
Tools required to service the touch control panel assembly.
1) Soldering iron: 30W
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 preventing static
electricity.
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.
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
Transistor
DTA123ES
KRA101M
KRC243M
DTA123ES
KRA101M
KRC243M
E
C
B
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
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 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.
and 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.
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.
(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
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.
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.
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.
itself is so short that the two can't be separated.
For those models, check and repair all the
R33ST - 14
1. CARRY OUT 3D CHECKS.
2. Make sure that a definite "click" can be heard when the
2. Make sure that a definite "click" can be heard when the
microwave oven door is unlatched. (Hold the door in a
closed position with one hand, then push the door open
button with the other, this causes the latch heads to rise,
it is then possible to hear a "click" as the door switches
operate.)
closed position with one hand, then push the door open
button with the other, this causes the latch heads to rise,
it is then possible to hear a "click" as the door switches
operate.)
3. Visually check the door and cavity face plate for damage
(dents, cracks, signs of arcing etc.).
Carry out any remedial work that is necessary before
operating the oven.
Do not operate the oven if any of the following conditions
exist;
1. Door does not close firmly.
operating the oven.
Do not operate the oven if any of the following conditions
exist;
1. Door does not close firmly.
COMPONENT REPLACEMENT AND ADJUSTMENT
WARNING: Avoid possible exposure to microwave energy. Please follow the instructions below before
operating the oven.
2. Door hinge, support or latch hook is damaged.
3. The door gasket or seal is damaged.
4. The door is bent or warped.
5. There are defective parts in the door interlock system.
6. There are defective parts in the microwave generating
3. The door gasket or seal is damaged.
4. The door is bent or warped.
5. There are defective parts in the door interlock system.
6. There are defective parts in the microwave generating
and transmission assembly.
7. There is visible damage to the oven.
Do not operate the oven:
1. Without the RF gasket (Magnetron).
2. If the wave guide or oven cavity are not intact.
3. If the door is not closed.
4. If the outer case (cabinet) is not fitted.
1. Without the RF gasket (Magnetron).
2. If the wave guide or oven cavity are not intact.
3. If the door is not closed.
4. If the outer case (cabinet) is not fitted.
Please refer to ‘OVEN PARTS, CABINET PARTS, DOOR PARTS’, when carrying out any of the following removal
procedures:
procedures:
MONITORED LATCH SWITCH, MONITORED SWITCH AND STOP SWITCH REMOVAL
MONITOR SWITCH (SW2)
STOP SWITCH (SW3)
MONITORED
LATCH SWITCH (SW1)
LATCH SWITCH (SW1)
TAB
TAB
TAB
1. CARRY OUT 3D CHECKS.
2. Remove the control panel assembly referring to
2. Remove the control panel assembly referring to
"CONTROL PANEL ASSEMBLY REMOVAL".
3. Disconnect the all leads from the switches.
4. Remove the two (2) screws holding the latch hook to the
4. Remove the two (2) screws holding the latch hook to the
oven cavity.
5. Remove the latch hook.
6. Push the retaining tab slightly and remove the switch.
6. Push the retaining tab slightly and remove the switch.
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