Electrolux EI24MO45IBA Technical & Service Manual page 22

Troubleshooting and Testing
Procedure
Letter
B POWER TRANSFORMER TEST
DO NOT TOUCH THE COMPONENTS OF THE POWER TRANSFORMER WHILE POWER
TRANSFORMER IS ENERGIZED. IT IS DANGEROUS BECAUSE THIS HAS HIGH VOLTAGE
COMPONENTS. (HIGH VOLTAGES ARE PRESENT AT THE HIGH VOLTAGE TERMINAL, SO
DO NOT ATTEMPT TO MEASURE THE FILAMENT AND HIGH VOLTAGE.)
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 primary input terminals and measure the resistance of the transformer with an
ohmmeter. Check for continuity of the coils with an ohmmeter. On the R x 3-4 scale, the resis-
tance of the primary coil should be less than 1 ohm and the resistance of the high voltage coil
should be approximately 90 ohms; the resistance of the filament coil should be less than 1 ohm.
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.
HIGH VOLTAGE RECTIFIER TEST
C
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. Isolate the rectifier from the circuit. Using the highest ohm scale of the meter, read the
resistance across the terminals and observe, reverse the leads to the rectifier terminals and
observe meter reading. If a short is indicated in both directions, or if an infinite resistance is
read in both directions, the rectifier is probably defective and should 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.
NOTE: Be sure to use an ohmmeter that will supply a forward bias voltage of more than 6.3 volts.
D
HIGH VOLTAGE CAPACITOR TEST
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. If the capacitor is open, no high voltage will be available to the magnetron. Disconnect input
leads and check for short or open between the terminals using an ohmmeter.
Checking with a high ohm scale, if the high voltage capacitor is normal, the meter will indicate
continuity for a short time and should indicate an open circuit once the capacitor is charged. If
the above is not the case, check the capacitor with an ohmmeter to see if it is shorted between
either of the terminals and case. If it is shorted, replace the capacitor.
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.
Component Test
3-4