Sharp R-334 (serv.man4) Service Manual ▷ View online
R-334 - 21
1-12
SEG0 -
OUT
Segment data signal.
SEG11
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 (1) .......................... S12(4)
SEG 0 (1) .......................... S12(4)
SEG 6 (7) ....................... S6(10)
SEG 1 (2) .......................... S11(5)
SEG 7 (8) ....................... S5(11)
SEG 2 (3) .......................... S10(6)
SEG 8 (9) ....................... S4(12)
SEG 3 (4) ............................ S9(7)
SEG 9 (10) ..................... S3(13)
SEG 4 (5) ............................ S8(8)
SEG 10 (11) ................... S2(14)
SEG 5 (6) ............................ S7(9)
SEG 11 (12) ................... S1(15)
13
R60
OUT
Tact switch strobe signal.
Signal applied to tact switch section. A pulse signal is input to R81 terminal while
the tact switch SW4 is touched.
Signal applied to tact switch section. A pulse signal is input to R81 terminal while
the tact switch SW4 is touched.
14
R61
OUT
Tact switch strobe signal.
Signal applied to tact switch section. A pulse signal is input to R81 terminal while
the tact switch SW3 is touched.
Signal applied to tact switch section. A pulse signal is input to R81 terminal while
the tact switch SW3 is touched.
15
R62
OUT
Tact switch strobe signal.
Signal applied to tact switch section. A pulse signal is input to R81 terminal while
the tact switch SW2 is touched.
Signal applied to tact switch section. A pulse signal is input to R81 terminal while
the tact switch SW2 is touched.
16
R63
OUT
Tact switch strobe signal.
Signal applied to tact switch section. A pulse signal is input to R81 terminal while
the tact switch SW1 is touched.
Signal applied to tact switch section. A pulse signal is input to R81 terminal while
the tact switch SW1 is touched.
17
AIN0
IN
To input signal which communicates the door open/close information to
LSI.
Door close "L" level signal (0V). Door open "H" level (+5V)
LSI.
Door close "L" level signal (0V). Door open "H" level (+5V)
18-20
AIN1-AIN3
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.
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.
21
VSS
IN
Power source voltage: 0V.
VSS voltage of power source circuit input.
VSS voltage of power source circuit input.
22
R70
OUT
Magnetron high-voltage circuit driving signal.
To turn on and off the cook relay
(RY2). The signals holds "L" level
during microwave cooking and "H"
level while not cooking. In other
cooking modes (variable cooking)
the signal turns to "H" level and "L"
level in repetition according to the
power level.
(RY2). The signals holds "L" level
during microwave cooking and "H"
level while not cooking. In other
cooking modes (variable cooking)
the signal turns to "H" level and "L"
level in repetition according to the
power level.
23
R71
OUT
Signal to sound buzzer (2.0 kHz).
A: key touch sound.
B: Completion sound.
24
R72
OUT
Oven lamp, fan motor and turntable motor driving signal.
To turn on and off shut off relay (RY1).
The square waveform voltage is deliv-
ered to the RY1 driving circuit.
The square waveform voltage is deliv-
ered to the RY1 driving circuit.
LSI(IZA088DR)
The I/O signal of the LSI(IXA088DR) are detailed in the following table.
The I/O signal of the LSI(IXA088DR) are detailed in the following table.
Pin No.
Signal
I/O
Description
20.0 msec
During cooking
H : +5V
L : 0V
A
B
0.1 sec.
2 sec.
H : +5V
L: 0V
H : +5V
L: 0V
HIGH
H : +5V
L : 0V
H : +5V
L : 0V
MEDIUM
HIGH
ON
ON
OFF
OFF
OFF
24 sec.
8 sec.
DESCRIPTION OF LSI
R-334 - 22
25
R73
IN
Signal coming from encoder.
When the encoder is turned, the contacts of encoder make pulse signals. And
pulse signals are input into R73.
When the encoder is turned, the contacts of encoder make pulse signals. And
pulse signals are input into R73.
26
INT2
IN
Signal synchronized with commercial power source frequency.
This is the basic timing for time processing of LSI.
27
R81
IN
Signal coming from tact switch.
When either of tact switches SW1-SW4 is touched, a corresponding signal out
of R60, R61, R62 and R63 will be input into R81. When no key is touched, the
signal is held at "H" level.
When either of tact switches SW1-SW4 is touched, a corresponding signal out
of R60, R61, R62 and R63 will be input into R81. When no key is touched, the
signal is held at "H" level.
28
INT1
IN
Signal coming from encoder.
Signal similar to R73. Pulse signals are input into INT1.
Signal similar to R73. Pulse signals are input into INT1.
29
R83
OUT
Terminal not used.
30-32
R90-R92
OUT
Terminal not used.
33
XIN
IN
Internal clock oscillation frequency setting input.
The internal clock frequency is set by inserting the capacitor and resistor circuit
with respect to XOUT terminal.
The internal clock frequency is set by inserting the capacitor and resistor circuit
with respect to XOUT terminal.
34
XOUT
OUT
Internal clock oscillation frequency control output.
Output to control oscillation input of XIN.
Output to control oscillation input of XIN.
35
RESET
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.
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.
36
HOLD
IN/OUT
Connected to VDD.
37
VLC
IN
Signal synchronized with commercial power source frequency.
Signal similar to VSS.
Signal similar to VSS.
38
COM1
OUT
Common data signal: COM1.
Connected to LCD (Pin No. 1)
Connected to LCD (Pin No. 1)
39
COM2
OUT
Common data signal: COM2.
Connected to LCD (Pin No. 2)
Connected to LCD (Pin No. 2)
40
COM3
OUT
Common data signal: COM1.
Connected to LCD (Pin No. 3)
Connected to LCD (Pin No. 3)
41
COM4
OUT
Terminal not used.
42
VDD
IN
Power source voltage input terminal.
Connected to VC.
Pin No.
Signal
I/O
Description
20.0 msec
H : +5V
L : 0V
LSI(IZA088DR)
The I/O signal of the LSI(IXA088DR) are detailed in the following table.
The I/O signal of the LSI(IXA088DR) are detailed in the following table.
DISCRIPTION OF LSI
R-334 - 23
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.
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 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 is so short
that the two can't be separated.
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.
E
C B
B. On some models, the power supply cord between
the touch control panel and the oven is 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 ; 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 ; 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, 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, 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
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 preventing
static electricity.
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.
Transistor
2SA1267Y
KRA101M
KRC101M
KRC105M
2SA1267Y
KRA101M
KRC101M
KRC105M
SERVICING OF TOUCH CONTROL PANEL
R-334 - 24
WARNING: Avoid possible exposure to microwave energy. Please follow the instructions below before
operating the oven.
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.
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:
OUTER CASE REMOVAL
To remove the outer case, proceed as follows.
1. Disconnect oven from power supply.
2. Open the oven door and wedge it open.
3. Remove the screws from rear and along the side edge
1. Disconnect oven from power supply.
2. Open the oven door and wedge it open.
3. Remove the screws from rear and along the side edge
of case.
4. Slide the entire case back about 3cm to free it from
retaining clips on the cavity face plate.
5. Lift the entire case from the oven.
6. Discharge the H.V. capacitor before carrying out any
further work.
7. Do not operate the oven with the outer case removed.
N.B.; Step 1, 2 and 6 form the basis of the 3D checks.
N.B.; Step 1, 2 and 6 form the basis of the 3D checks.
CAUTION: DISCHARGE HIGH VOLTAGE
CAPACITOR BEFORE TOUCHING ANY
OVEN COMPONENTS OR WIRING.
OVEN COMPONENTS OR WIRING.
HIGH VOLTAGE COMPONENTS REMOVAL
(HIGH VOLTAGE CAPACITOR AND HIGH VOLTAGE RECTIFIER ASSEMBLY)
To remove the components, proceed as follows.
1. CARRY OUT 3D CHECKS
2. Disconnect all the leads and terminals of high voltage
2. Disconnect all the leads and terminals of high voltage
rectifier assembly from high voltage capacitor.
3. Remove one (1) screw holding earth side terminal of
high voltage rectifier assembly, and remove capacitor
holder.
holder.
4. Remove one (1) screw holding capacitor holder to the
oven cavity.
5. Release the capacitor holder from the duct.
6. Remove the capacitor from the capacitor holder.
7. Now high voltage rectifier assembly and capacitor should
7. Now high voltage rectifier assembly and capacitor should
be free.
CAUTION: WHEN REPLACING HIGH VOLTAGE
RECTIFIER ASSEMBLY, ENSURE THAT
THE CATHODE (EARTH) CONNECTION
IS SECURELY FIXED TO THE
CAPACITOR HOLDER WITH AN
EARTHING SCREW.
THE CATHODE (EARTH) CONNECTION
IS SECURELY FIXED TO THE
CAPACITOR HOLDER WITH AN
EARTHING SCREW.
POWER TRANSFORMER REMOVAL
4. Remove the two (2) screws and one (1) washer holding
the transformer to base plate.
5. Remove the transformer.
6. Now, the power transformer is free.
6. Now, the power transformer is free.
1. CARRY OUT 3D CHECKS
2. Disconnect the filament leads of the power transformer
2. Disconnect the filament leads of the power transformer
from high voltage capacitor and the magnetron.
3. Disconnect the secondary coil lead from the H.V
capacitor.
1. CARRY OUT 3D CHECKS.
2. Remove the air intake duct B from the chassis support.
3. Disconnect the H.V. wire B and filament lead of the
2. Remove the air intake duct B from the chassis support.
3. Disconnect the H.V. wire B and filament lead of the
transformer from the magnetron.
4. Remove the one (1) screw holding the chassis support
to the magnetron.
5. Remove the one (1) screw holding the chassis support
to the noise filter unit.
6. Remove the one (1) screw holding the chassis support
to the cavity face plate.
MAGNETRON REMOVAL
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
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