Sharp R-362M (serv.man2) Service Manual ▷ View online
R362M - 7
COMPONENT TEST
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.
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.
the control 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.
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking 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
RY2
Approx. 18.0V D.C.
High voltage transformer
RY5
Approx. 24.0V D.C.
Fan motor / Turntable motor / Oven lamp
CARRY OUT 4R CHECKS.
(J1)
9
8
a
d
c
b
C2
VRS1
RY3
5 FAN
AC 1 - 5
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.
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.
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.)
PROCEDURE
LETTER
C
RELAY TEST
D
PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING BOARD
(PWB) IS OPEN
(PWB) IS OPEN
TEST PROCEDURE (CONT'D)
R362M - 8
TEST PROCEDURE (CONT'D)
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
(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.
space 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",
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",
"VEGETABLES", "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:
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:
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.
R362M - 9
(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:
(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
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.
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
TEST PROCEDURE (CONT'D)
PROCEDURE
LETTER
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
R362M - 10
TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOUCH CONTROL PANEL
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
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
emit audible sounds (key touch sound and completion
sound).
emit 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, fan motor, turntable motor
and light the oven lamp.
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 of 7-digits, 39-segments and 3-
common electrodes using a Liquid Crystal Display.
common electrodes using a Liquid Crystal Display.
10) Absolute Humidity Sensor Circuit
This circuit detects the humidity of a food which
is being cooked, to control its automatic cooking.
is 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 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.
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, absolute
humidity sensor circuit and back light circuit.
ing 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
VC
-5.2V
LSI(IC1)
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