Troubleshooting and Testing
3-11
Procedure
Letter
Component Test
1. 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 the power supply cord, and then remove outer case.
2. Discharge high voltage capacitor. (See Warnings and Instructions on page 3-1)
3. Remove the AH sensor.
4. Install the new AH sensor.
5. Re-install the outer case (cabinet).
6. Reconnect the power supply cord after the outer case is installed.
7. Reconnect the oven to the power supply and check the sensor cook operation as follows:
a) Fill approximately 200 milliliters (7.2 oz) of tap water in a 1000 milliliter measuring cup.
b) Place the container on the center of tray in the oven cavity.
c) Close the door.
d) Touch SENSOR COOK pad and number 1 pad.
e) Touch Start pad. The control panel is in automatic Sensor operation.
f) The display will start to count down the remaining cooking time, and the oven will turn off
automatically after the water is boiling (bubbling).
If new sensor dose not operate properly, the problem is with the control unit.
2. CHECKING CONTROL UNIT
1. Disconnect the power supply cord, and then remove outer case.
2. Discharge high voltage capacitor.
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 oven to the power supply and check the sensor cook operation proceed as follows:
6-1. Touch BAKED POTATO pad and number 1 pad.
6-2. Touch Start pad. The control panel is in the sensor cooking operation.
6-3. After approximately 20 seconds, push plunger of select switch for more than 3 seconds.
This condition is same as judgement by AH sensor.
6-4. 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.
R1,R2 :
22
± 1% 1/2W
R3 ...... : 4.3k
± 5% 1/4W
R4 ...... : 1M
± 5% 1/4W
Plunger
NC
NO
COM
COM
NO
NC
R3
R4
R1
R2
1
2
3
F-1
F-2
F-3
To connector (F)
on Control Unit.
CONNECTOR
Summary of Contents for EW27MO55HSA
Page 2: ......
Page 30: ...Troubleshooting and Testing 3 12 Notes ...
Page 40: ...Component Teardown 4 10 Notes ...
