Test Procedures - Electrolux EI30MH55GBA Technical & Service Manual

Troubleshooting

Test Procedures

Procedure
Letter
MAGNETRON ASSEMBLY TEST
A
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. To test for an open filament, isolate the magnetron from the high voltage circuit.
A continuity check across the magnetron filament leads should indicate less than 1 ohm.
4. To test for a shorted magnetron, connect the ohmmeter leads between the magnetron
filament leads and chassis ground. This test should indicate an infinite resistance. If there
is little or no resistance the magnetron is grounded and must be replaced.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
MICROWAVE OUTPUT POWER
The following test procedure should be carried out with the microwave oven in a fully assembled
condition (outer case fitted).
HIGH VOLTAGES ARE PRESENT DURING THE COOK CYCLE, SO EXTREME CAUTION
SHOULD BE OBSERVED.
Power output of the magnetron can be measured by performing a water temperature rise test.
This test should only be used if above tests do not indicate a faulty magnetron and there is no
defect in the following components or wiring: inverter unit. This test will require a 16 ounce
(453cc) measuring cup and an accurate mercury thermometer or thermocouple type tempera-
ture tester. For accurate results, the following procedure must be followed carefully:
1. Fill the measuring cup with 1 6 oz. (453cc) of tap water and measure the temperature of
the water with a thermometer or thermocouple temperature tester. Stir the thermometer or
thermocouple through the water until the temperature stabilizes. Record the temperature
of the water.
2. Place the cup of water in the oven. Operate oven at POWER 10(HIGH) selecting more
than 60 seconds cook time. Allow the water to heat for 60 seconds, measuring with a stop
watch, second hand of a watch or the digital read-out countdown.
3. Remove cup from oven and again measure the temperature, making sure to stir the
thermometer or thermocouple through the water until the maximum temperature is
recorded.
4. Subtract the cold water temperature from the hot water temperature. The normal result
should be 39.2 to 63F(21.8 to 35C) rise in temperature. If the water temperatures are
accurately measured and tested for the required time period the test results will indicate if
the magnetron tube has low power output (low rise in water temperature) which would
extend cooking time or high power output (high rise in water temperature) which would
reduce cooking time. Because cooking time can be adjusted to compensate for power
output, the magnetron tube assembly should be replaced only if the water temperature
rise test indicates a power output well beyond the normal limits. The test is only accurate
if the power supply line voltage is 120 volts and the oven cavity is clean.
Component Test
3-4