Sharp R-84ST (serv.man6) Service Manual ▷ View online
R-84STM - 9
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
C
RELAY TEST
D
PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING
BOARD(PWB) IS OPEN
NOTE: *At the time of these repairs, make a
visual inspection of the varistor for burn-
ing damage and examine the trans-
former with tester for the presence of
layer short circuit (check primary coil
resistance).
If any abnormal condition is detected,
replace the defective parts.
ing damage and examine the trans-
former with tester for the presence of
layer short circuit (check primary coil
resistance).
If any abnormal condition is detected,
replace the defective parts.
CARRY OUT 4R CHECKS.
To protect the electronic circuits, this model is provided with a fine foil pattern added to the input circuit on
the PWB, this foil pattern acts as a fuse. If the foil pattern is open, follow the troubleshooting guide given
below for repair.
Problem: POWER ON, indicator does not light up.
the PWB, this foil pattern acts as a fuse. If the foil pattern is open, follow the troubleshooting guide given
below for repair.
Problem: POWER ON, indicator does not light up.
CARRY OUT 3D CHECKS.
STEPS
OCCURRENCE
CAUSE OR CORRECTION
1
The rated AC voltage is not present between
Check supply voltage and oven power cord.
Pin Nos. 1 and 3 of the 4-pin connector (E).
2
The rated AC voltage is present at primary
Low voltage transformer or secondary circuit defective.
side of low voltage transformer.
Check and repair.
3
Only pattern at "a" is broken.
*Insert jumper wire J1 and solder.
(CARRY OUT 3D CHECKS BEFORE REPAIR.)
4
Pattern at "a" and "b" are broken.
*Insert the coil RCILF2003YAZZ between "c" and "d".
(CARRY OUT 3D CHECKS BEFORE REPAIR.)
CARRY OUT 3D CHECKS.
Remove the outer case and check voltage between Pin Nos. 1 and 3 of the 4 pin connector (E) on the control
unit with an A.C. voltmeter.
The meter should indicate 230-240 volts, if not check oven circuit.
unit with an A.C. voltmeter.
The meter should indicate 230-240 volts, if not check oven circuit.
Relay Test
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation, grill
operation, convection operation or dual operation.
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation, grill
operation, convection operation or dual operation.
DC. voltage indicated ............. Defective relay.
DC. voltage not indicated ....... Check diode which is connected to the relay coil. If diode is good, control
DC. voltage not indicated ....... Check diode which is connected to the relay coil. If diode is good, control
unit is defective.
RELAY SYMBOL
OPERATIONAL VOLTAGE
CONNECTED COMPONENTS
RY1
Approx. 18.0V D.C.
Oven lamp / Turntable motor
RY2
Approx. 18.0V D.C.
High voltage transformer
RY3
Approx. 24.0V D.C.
Grill (Top) heating element
RY4
Approx. 24.0V D.C.
Bottom heating element
RY5
Approx. 24.0V D.C.
Touch control transformer
RY6
Approx. 24.0V D.C.
Fan motor
RY7
Approx. 24.0V D.C.
Convection motor
CARRY OUT 4R CHECKS.
7
9
1
RY4
(J1)
(J2)
FM
POWER
a
b
c
d
F
CN - E
CN - A
VRS1
RY6
R-84STM - 10
TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOUCH CONTROL PANEL
initial state when power is supplied.
5) Buzzer Circuit
The buzzer is responsive to signals from the LSI to emit
audible sounds (key touch sound and completion sound).
audible sounds (key touch sound and completion sound).
6) Stop Switch
A switch to "tell" the LSI if the door is open or closed.
7) Relay Circuit
To drive the magnetron, grill heating element, bottom
heating element, convection motor, fan motor, turntable
motor, touch control transformer and light the oven lamp.
heating element, convection motor, fan motor, turntable
motor, touch control transformer and light the oven lamp.
8) Back Light Circuit
A circuit to drive the back light (Light emitting diodes LD1
- LD10).
- LD10).
9) Indicator Circuit
This circuit consists 7-digits, 39-segments and 3-common
electrodes using a Liquid Crystal Display.
electrodes using a Liquid Crystal Display.
10) Temperature Measurement Circuit : (OVEN
THERMISTOR)
The temperature in the oven cavity is sensed by the
thermistor. The variation of resistance according to
sensed temperature is detected by the temperature
measurement circuit and the result applied to LSI.
The LSI uses this information to control the relay
and display units.
The temperature in the oven cavity is sensed by the
thermistor. The variation of resistance according to
sensed temperature is detected by the temperature
measurement circuit and the result applied to LSI.
The LSI uses this information to control the relay
and display units.
The touch control section consists of the following units as
shown in the touch control panel circuit.
shown in the touch control panel circuit.
(1) Key Unit
(2) Control Unit (The Control unit consists of Power unit and
(2) Control Unit (The Control unit consists of Power unit and
CPU unit.)
The principal functions of these units and signals communi-
cated among them are explained below.
cated 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 from P40, P41, P72, P73 P74, P75,
P76 and P77.
When a key pad is touched, a signal is completed through the
key unit and passed back to the LSI through P44 - P47 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 from P40, P41, P72, P73 P74, P75,
P76 and P77.
When a key pad is touched, a signal is completed through the
key unit and passed back to the LSI through P44 - P47 to
perform the function that was requested.
Control Unit
Control unit consists of LSI, power source circuit, synchroniz-
ing signal circuit, ACL circuit, buzzer circuit, relay circuit,
temperature measurement circuit, indicator circuit and back
light circuit.
Control unit consists of LSI, power source circuit, synchroniz-
ing signal circuit, ACL circuit, buzzer circuit, relay circuit,
temperature measurement circuit, indicator circuit and back
light circuit.
1) LSI
This LSI controls the temperature measurement signal,
key strobe signal, relay driving signal for oven function
and indicator signal.
key strobe signal, relay driving signal for oven function
and indicator signal.
2) Power Source Circuit
This circuit generates voltage necessary in the control
unit.
unit.
Symbol
Voltage
Application
VC
-5.2V
LSI(IC1)
3) Synchronizing Signal Circuit
The power source synchronizing signal is available in
order to compose a basic standard time in the clock circuit.
It accompanies a very small error because it works on
commercial frequency.
order to compose a basic standard time in the clock circuit.
It accompanies a very small error because it works on
commercial frequency.
4) ACL
A circuit to generate a signal which resets the LSI to the
R-84STM - 11
TOUCH CONTROL / DESCRIPTION OF LSI
LSI(IXA094DR)
The I/O signal of the LSI(IXA094DR) are detailed in the following table.
The I/O signal of the LSI(IXA094DR) are detailed in the following table.
Pin No.
Signal
I/O
Description
A
B
C
H: GND
L
0.12 sec
2.4 sec
1.2 sec
1.2 sec
20 msec.
H : GND
L (-5V)
1
C1
IN
Terminal not used.
2
VL1
IN
Power source voltage input terminal.
Standard voltage for LCD.
Standard voltage for LCD.
3
AN7
IN
Terminal to change the on timing of the cook relay (RY2).
4-5
AN6-AN5
IN
Heating constant compensation terminal.
6
AN4
OUT
Terminal not used.
7
AN3
IN
Temperature measurement input: OVEN THERMISTOR.
By inputting DC voltage corresponding to the temperature detected by the
thermistor, this input is converted into temperature by the A/D converter built
into the LSI.
By inputting DC voltage corresponding to the temperature detected by the
thermistor, this input is converted into temperature by the A/D converter built
into the LSI.
8
AN2
IN
Input signal which communicates the door open/close information to LSI.
Door closed; "H" level signal.
Door opened; "L" level signal.
Door opened; "L" level signal.
9-10
AN1-AN0
OUT
Terminal not used.
11
P57
OUT
Timing signal output terminal for temperature measurement(OVEN
THERMISTOR).
"H" level (GND) : Thermistor OPEN timing.
"L" level (-5V) : Temperature measuring timing. (Convection cooking)
THERMISTOR).
"H" level (GND) : Thermistor OPEN timing.
"L" level (-5V) : Temperature measuring timing. (Convection cooking)
12
P56
OUT
Signal to sound buzzer.
A: key touch sound.
B: Completion sound.
C: When the temperature of the oven
A: key touch sound.
B: Completion sound.
C: When the temperature of the oven
cavity reaches the preset
temperature in the preheating
mode, or when the preheating hold
time (30 minutes) is elapsed.
temperature in the preheating
mode, or when the preheating hold
time (30 minutes) is elapsed.
13
P55
OUT
Timing signal output terminal for temperature measurement(OVEN
THERMISTOR).
"H" level (GND) : Thermistor OPEN timing.
"L" level (-5V) : Temperature measuring timing. (Convection cooking)
THERMISTOR).
"H" level (GND) : Thermistor OPEN timing.
"L" level (-5V) : Temperature measuring timing. (Convection cooking)
14-18
P54-P50
OUT
Terminal not used.
19
P47
IN
Signal coming from touch key.
When any one of G12 line keys on key matrix is touched, a corresponding
signal from P40, P41, P72, P73, P74, P75, P76 and P77 will be input into P47.
When no key is touched, the signal is held at "L" level.
When any one of G12 line keys on key matrix is touched, a corresponding
signal from P40, P41, P72, P73, P74, P75, P76 and P77 will be input into P47.
When no key is touched, the signal is held at "L" level.
20
P46
IN
Signal similar to P47.
When any one of G11 line keys on key matrix is touched, a corresponding
signal will be input into P46.
When any one of G11 line keys on key matrix is touched, a corresponding
signal will be input into P46.
21
P45
IN
Signal similar to P47.
When any one of G10 line keys on key matrix is touched, a corresponding
signal will be input into P45.
When any one of G10 line keys on key matrix is touched, a corresponding
signal will be input into P45.
22
P44
IN
Signal similar to P47.
When any one of G9 line keys on key matrix is touched, a corresponding signal
will be input into P44.
When any one of G9 line keys on key matrix is touched, a corresponding signal
will be input into P44.
23
INT1
OUT
Terminal not used.
24
INT0
IN
Signal to synchronized LSI with commercial power source
frequency(50Hz).
This is basic timing for time processing
of LSI.
frequency(50Hz).
This is basic timing for time processing
of LSI.
25
P41
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P44 - P47
terminal while one of G8 line key on matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P44 - P47
terminal while one of G8 line key on matrix is touched.
R-84STM - 12
TOUCH CONTROL / DESCRIPTION OF LSI
LSI(IXA094DR)
The I/O signal of the LSI(IXA094DR) are detailed in the following table.
The I/O signal of the LSI(IXA094DR) are detailed in the following table.
Pin No.
Signal
I/O
Description
ON/OFF time ratio in Micro
cooking
(a. 32second time base)
cooking
(a. 32second time base)
ON/OFF time ratio in Micro
cooking
(a. 48second time base)
cooking
(a. 48second time base)
MICRO
ON
OFF
COOK
100%
32 sec.
0 sec.
70%
24 sec.
8 sec.
50%
18 sec. 14 sec.
30%
12 sec. 20 sec.
10%
6 sec. 26 sec.
MICRO
ON
OFF
COOK
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.
Power output
ON time
OFF time
100 %
48 sec.
0 sec.
90 %
44 sec.
4 sec.
80 %
40 sec.
8 sec.
70 %
36 sec.
12 sec.
60 %
32 sec.
16 sec.
50 %
26 sec.
22 sec.
40 %
22 sec.
26 sec.
30 %
16 sec.
32 sec.
20 %
12 sec.
36 sec.
10 %
8 sec.
40 sec.
During cooking
L
H
20 msec.
26
P40
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P44 - P47
terminal while one of G7 line key on matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P44 - P47
terminal while one of G7 line key on matrix is touched.
27
P77
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P44 - P47
terminal while one of G6 line key on matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P44 - P47
terminal while one of G6 line key on matrix is touched.
28
P76
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P44 - P47
terminal while one of G5 line key on matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P44 - P47
terminal while one of G5 line key on matrix is touched.
29
P75
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P44 - P47
terminal while one of G4 line key on matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P44 - P47
terminal while one of G4 line key on matrix is touched.
30
P74
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P44 - P47
terminal while one of G3 line key on matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P44 - P47
terminal while one of G3 line key on matrix is touched.
31
P73
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P44 - P47
terminal while one of G2 line key on matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P44 - P47
terminal while one of G2 line key on matrix is touched.
32
P72
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P44 - P47
terminal while one of G1 line key on matrix is touched.
Signal applied to touch-key section. A pulse signal is input to P44 - P47
terminal while one of G1 line key on matrix is touched.
33
P71
OUT
Oven lamp and turntable motor driving signal(Square Waveform : 50Hz).
To turn on and off shut-off relay
(RY1). The square waveform voltage
is delivered to the relay (RY1) driving
circuit.
(RY1). The square waveform voltage
is delivered to the relay (RY1) driving
circuit.
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.
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.
36
P81
OUT
Magnetron high-voltage circuit driving signal.
To turn on and off the cook
relay (RY2). In 100%
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 (RY2). In 100%
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.
37
P80
OUT
Grill (TOP) heating element driving signal.
To turn on and off the grill heating
element relay (RY3). "L" level
during grill cooking, convection
cooking or dual cooking, "H" level
otherwise. The heater relay turns
on and off within a 48 second time
base in accordance with the
special program in LSI.
element relay (RY3). "L" level
during grill cooking, convection
cooking or dual cooking, "H" level
otherwise. The heater relay turns
on and off within a 48 second time
base in accordance with the
special program in LSI.
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