Sharp R-320CD Service Manual page 22

R-320CD/CK/CW
R-330CK/CW
PROCEDURE
LETTER
If new sensor dose not operate properly, the problem is with the control unit, and refer to explanation
below.
(1) Disconnect the power supply cord, and then remove outer case.
(2) Open the door and block it open.
(3) Discharge high voltage capacitor.
(4) Disconnect the sensor connector that is mounted to control panel.
(5) Then connect the dummy resistor circuit (see fig.) to the sensor connector of control panel.
(6) Disconnect the leads to the primary of the power transformer.
(7) Ensure that these leads remain isolated from other components and oven chassis by using
insulation tape.
(8) After that procedure, re-connect the power supply cord.
(9) Check the sensor cook operation proceed as follows:
(10) Disconnect the power supply cord, and then remove outer case.
(11) Open the door and block it open.
(12) Discharge high voltage capacitor.
(13) Disconnect the dummy resistor circuit from the sensor connector of control panel.
(14) Carry out necessary repair.
(15) Reconnect all leads removed from components during testing and repairing.
(16) Re-install the outer case (cabinet).
(17) Reconnect the power supply cord after the outer case is installed. Run the oven and check all
functions.
(18) Carry out "Water load cooking test" again and ensure that the oven works properly.
TEST PROCEDURES
9-1. Fill approximately 200 milliliters (7.2 oz) of tap water in a 1000 milliliter measuring cup.
9-2. Place the container on the center of tray in the oven cavity.
9-3. Close the door.
9-4. For R-320CD/CK/CW, touch REHEAT SENSOR pad once.
For R-330CK/CW, touch Sensor Reheat pad and touch the Start pad.
9-5. The control panel is in automatic Sensor operation.
9-6. The display will start to count down the remaining cooking time, and the oven will turn off
automatically after the water is boiling (bubbling).
9-1. For R-320CD/CK/CW, touch REHEAT SENSOR pad once.
For R-330CK/CW, touch Sensor Reheat pad and touch
9-2. The control panel is in the sensor cooking operation.
9-3. After approximately 20 seconds, push plunger of select switch for more than 3 seconds. This
condition is same as judgement by AH sensor.
9-4. After approximately 3 seconds, the display shows " X X . X X " which is the remaining cooking
time, and the display count down.
If the above is not the case, the control unit is probably defective.
If the above is proper, the AH sensor is probably defective.
To connector (F)
on Control Unit.
F-1
F-2
F-3
CONNECTOR
COMPONENT TEST
CHECKING CONTROL UNIT
R1, R2 : 22 1% 1/2W
R3 : 4.3k 5% 1/4W
R4 : 1M 5% 1/4W
1
2
R1
3
R3 R4
R2
Sensor Dummy Resistor Circuit
20
the Start pad.
Plunger
NC
NO
COM
NO
COM
NC