Sharp R-962M Service Manual ▷ View online
R-962M - 9
PROCEDURE
LETTER
COMPONENT TEST
E
AH SENSOR TEST
Checking the initial sensor cooking condition
(1) The oven should be plugged in at least two minutes before sensor cooking.
(2) Room temperature should not exceed 35˚C.
(3) The unit should not be installed in any area where heat and steam are generated. The unit should not
(2) Room temperature should not exceed 35˚C.
(3) The unit should not be installed in any area where heat and steam are generated. The unit should not
be installed, for example, next to a conventional surface unit. Refer to the "INSTALLATION
Instructions" .
Instructions" .
(4) Exhaust vents are provided on the back of the unit for proper cooling and air flow in the cavity. To permit
adequate ventilation, be sure to install so as not to block these vents. There should be some space
for air circulation.
for air circulation.
(5) Be sure the exterior of the cooking container and the interior of the oven are dry. Wipe off any moisture
with a dry cloth or paper towel.
(6) The Sensor works with food at normal storage temperature. For example, chicken pieces would be
at refrigerator temperature and canned soup at room temperature.
(7) Avoid using aerosol sprays or cleaning solvents near the oven while using Sensor settings. The sensor
will detect the vapor given of by the spray and turn off before food is properly cooked.
(8) After the oven is started on sensor cooking condition, if the sensor has not detected the vapor of the
food, ERROR will appear and the oven will shut off.
Water load cooking test
Make sure the oven has been plugged in at least five minutes before checking sensor cook operation.
The cabinet should be installed and screws tightened.
(1) Fill approximately 200 milliliters (7.2 oz) of tap water in a 1000 milliliter measuring cup.
(2) Place the container on the center of tray in the oven cavity.
(3) Close the door.
(4) Touch FRESH VEG. pad. Now, the oven is in the sensor cooking condition and "FRESH", "VEG.",
The cabinet should be installed and screws tightened.
(1) Fill approximately 200 milliliters (7.2 oz) of tap water in a 1000 milliliter measuring cup.
(2) Place the container on the center of tray in the oven cavity.
(3) Close the door.
(4) Touch FRESH VEG. pad. Now, the oven is in the sensor cooking condition and "FRESH", "VEG.",
"SENSOR" and "COOKING" will appear in the display.
(5) The oven will operate for the first 16 seconds, without generating microwave energy.
When the AH sensor is defective (open or short), ERROR will appear in the display immediately.
If ERROR appears check sensor wire connections and/or AH sensor.
NOTE: ERROR will appear if the door is opened or STOP/CLEAR pad is touched during first stage of
If ERROR appears check sensor wire connections and/or AH sensor.
NOTE: ERROR will appear if the door is opened or STOP/CLEAR pad is touched during first stage of
sensor cooking.
(6) After approximately 16 seconds, microwave energy is produced, and the display should start to count
down the remaining cooking time and oven should turn off after water is boiling (bubbling).
If the oven does not turn off, replace the AH sensor or check the control unit, refer to explanation below.
If the oven does not turn off, replace the AH sensor or check the control unit, refer to explanation below.
TESTING METHOD FOR AH SENSOR AND/OR CONTROL UNIT
To determine if the sensor is defective, the simplest method is to replace it with a new replacement sensor.
(1) Disconnect oven from power supply and then remove outer case.
(2) Discharge the high voltage capacitor.
(3) Remove the AH sensor.
(4) Install the new AH sensor.
(5) Re-install the outer case.
(6) Reconnect the oven to the power supply and check the sensor cook operation, proceed as follows:
(1) Disconnect oven from power supply and then remove outer case.
(2) Discharge the high voltage capacitor.
(3) Remove the AH sensor.
(4) Install the new AH sensor.
(5) Re-install the outer case.
(6) Reconnect the oven to the power supply and check the sensor cook operation, proceed as follows:
6-1. Fill approximately 200 milliliters (7.2 oz) of tap water in a 1000 milliliter measuring cup.
6-2. Place the container on the center of tray in the oven cavity.
6-3. Close the door.
6-4. Touch FRESH VEG. pad.
6-5. The control panel is in automatic Sensor operation.
6-6. The display will start to count down the remaining cooking time, and the oven will turn off
6-2. Place the container on the center of tray in the oven cavity.
6-3. Close the door.
6-4. Touch FRESH VEG. pad.
6-5. The control panel is in automatic Sensor operation.
6-6. The display will start to count down the remaining cooking time, and the oven will turn off
automatically after the water is boiling (babbling).
If new sensor dose not operate properly, the problem is with the control unit.
CHECKING CONTROL UNIT
(1) Disconnect oven from power supply and then remove outer case.
(2) Discharge the high voltage capacitor.
(2) Discharge the high voltage capacitor.
TEST PROCEDURES
(
CONT'D
)
R-962M - 10
(3) Disconnect the wire leads from the cook relay.
(4) Disconnect the sensor connector that is mounted to lower portion of control panel.
(5) Then connect the dummy resistor circuit (see fig.) to the sensor connector of control panel.
(6) Reconnect the oven to the power supply and check the sensor cook operation, proceed as follows:
6-1. Touch FRESH VEG. pad.
6-2. The control panel is in the sensor cooking operation.
6-3. After approximately 1 minute and 15 seconds, push plunger of select switch. This condition is same
as judgement by AH sensor.
6-4. After approximately 3 seconds, the oven stops.
If the above is not the case, the control unit is probably defective.
If the above is proper, the AH sensor is probably defective.
(4) Disconnect the sensor connector that is mounted to lower portion of control panel.
(5) Then connect the dummy resistor circuit (see fig.) to the sensor connector of control panel.
(6) Reconnect the oven to the power supply and check the sensor cook operation, proceed as follows:
6-1. Touch FRESH VEG. pad.
6-2. The control panel is in the sensor cooking operation.
6-3. After approximately 1 minute and 15 seconds, push plunger of select switch. This condition is same
as judgement by AH sensor.
6-4. After approximately 3 seconds, the oven stops.
If the above is not the case, the control unit is probably defective.
If the above is proper, the AH sensor is probably defective.
R1,R2 :
22
Ω
±
1% 1/2W
R3 :
4.3k
Ω
±
5% 1/4W
R4 :
1M
Ω
±
5% 1/4W
Sensor Dummy Resistor Circuit
PROCEDURE
LETTER
TEST PROCEDURES
(
CONT'D
)
COMPONENT TEST
Plunger
NC
NO
COM
COM
NO
NC
R3
R4
R1
R2
1
2
3
F-1
F-2
F-2
F-3
To connector (F)
on Control Unit.
on Control Unit.
CONNECTOR
R-962M - 11
TOUCH CONTROL ASSEMBLY
TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOUCH CONTROL PANEL
4) ACL
A circuit to generate a signal which resets the LSI to the
initial state when power is supplied.
initial state when power is supplied.
5) Buzzer Circuit
The buzzer is responsive to signals from the LSI to emi
audible sounds (key touch sound and completion
sound).
audible sounds (key touch sound and completion
sound).
6) Door Sensing Switch (Stop Switch)
A switch to "tell" the LSI if the door is open or closed
7) Relay Circuit
To drive the magnetron, grill heaters, convection heater,
convection motor, fan motor, turntable motor, damper
motor, touch control transformer and light the oven
lamp.
convection motor, fan motor, turntable motor, damper
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).
LD1 - LD10).
9) Indicator Circuit
This circuit consists 7-digits, 39-segments and 3-
common electrodes using a Liquid Crystal Display.
common electrodes using a Liquid Crystal Display.
10) Temperature Measurement Circuit : (OVEN THER-
MISTOR)
The temperature in the oven cavity is sensed by the
thermistor. The variation of resistance according to
sensed temperature is detected by the temperatur
measurement circuit and the result applied to LSI. The
LSI uses this information to control the relay and
display units.
thermistor. The variation of resistance according to
sensed temperature is detected by the temperatur
measurement circuit and the result applied to LSI. The
LSI uses this information to control the relay and
display units.
11) Absolute Humidity Sensor Circuit
This circuit detects the humidity of a food which is
being cooked, to control its automatic cooking.
being cooked, to control its automatic cooking.
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
(2) Control Unit (The Control unit consists of Power unit
and CPU unit.)
The principal functions of these units and signals commu-
nicated among them are explained below.
nicated 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 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, synchro-
nizing signal circuit, ACL circuit, buzzer circuit, relay
circuit, temperature measurement circuit, indicator circuit,
absolute humidity sensor circuit and back light circuit.
nizing signal circuit, ACL circuit, buzzer circuit, relay
circuit, temperature measurement circuit, indicator circuit,
absolute humidity sensor circuit and back light circuit.
1) LSI
This LSI controls the temperature measurement signal,
AH sensor signal, key strobe signal, relay driving signal
for oven function and indicator signal.
AH sensor 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
V C
-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.
R-962M - 12
DESCRIPTION OF LSI
LSI(IZA963DR)
The I/O signal of the LSI(IZA963DR) 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
1
C1
IN
Terminal not used.
2
VL1
IN
Power source voltage input terminal.
Standard voltage for LCD.
3
AN7
IN
Terminal not 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.
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.
LSI.
Door closed; "H" level signal.
Door opened; "L" level signal.
Door opened; "L" level signal.
9
AN1
IN
AH sensor input.
This input is an analog input terminal from the AH sensor circuit, and
connected to the A/D converter built into the LSI.
connected to the A/D converter built into the LSI.
10
AN0
IN
Used for initial balancing of the bridge circuit (absolute humidity sensor). This
input is an analog input terminal from the AH sensor circuit, and connected to
the A/D converter built into LSI.
This input is an analog input terminal from the AH sensor circuit, and
connected to the A/D converter built into the LSI.
input is an analog input terminal from the AH sensor circuit, and connected to
the A/D converter built into LSI.
This input is an analog input terminal from the AH sensor circuit, and
connected to the A/D converter built into the LSI.
11
P57
OUT
Timing signal output terminal for temperature measurement(OVEN
THERMISTOR).
THERMISTOR).
"H" level (GND) : Thermistor OPEN timing.
"L" level (-5V) : Temperature measuring timing. (Convection cooking)
"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
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).
THERMISTOR).
"H" level (GND) : Thermistor OPEN timing.
"L" level (-5V) : Temperature measuring timing. (Convection cooking)
"L" level (-5V) : Temperature measuring timing. (Convection cooking)
14-18
P54-P50
OUT
Used for initial balancing of the bridge circuit (absolute humidity sensor).
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.
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.
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.
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.
signal will be input into P44.
23
INT1
OUT
Terminal not used.
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