Electrolux ICON E30SO75ESS Technical & Service Manual page 34

Troubleshooting and Testing
Procedure
Letter
T CHECKING TEMPERATURE IN THE CONVECTION MODE
The following test procedure should be carried out with the microwave oven is a fully assembled
condition (outer case fitted).
It is difficult to measure the exact temperature in the convection oven. An accurate thermocouple
type temperature tester must be used. A low priced bi-metal type thermometer is not reliable or
accurate. The temperature should be checked with outer case cabinet installed, approx. 5 minutes
after preheat temperature is reached (audible signal sounds four times). The temperature may be
approx. 30½°F more or less than indicated on the display, however, in most cases the food cooking
results will be satisfactory.
Difference in power supply voltage will also affect oven temperature. Household power supply
voltage may sometimes become lower than the rated voltage (240 V) and cause under-cooking. If
power supply voltage is 10% lower than rated voltage, longer cooking time is required by 10% to
20%.
TOUCH CONTROL PANEL ASSEMBLY TEST
U
The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc.
Therefore, unlike conventional microwave ovens, proper maintenance cannot be performed with only
a voltmeter and ohmmeter.
In this service manual, troubleshooting by unit replacement is described according to the symptoms
indicated.
Before testing,
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor. (See Warnings and Instructions on page 3-1)
4. Disconnect the leads to the primary of the power transformer.
5. Ensure that these leads remain isolated from other components and oven chassis by using
insulation tape.
1. Key Unit Panel
1. Re-install the outer case (cabinet).
2. Reconnect the power supply cord after the outer case is installed.
3. Run the oven and check all functions.
The following symptoms indicate a defective Key Unit Panel.
a. When touching the pads, a certain pad produces no signal at all.
b. When touching a number pad, two figures or more are displayed.
c. When touching the pads, sometimes a pad produces no signal.
If the Key Unit Panel is defective.
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor. (See Warnings and Instructions on page 3-1)
4. Replace the tact switch.
5. Reconnect all leads removed from components during testing.
6. Re-install the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
Component Test
3-12