Electrolux EI30BM55HB - 30" Microwave Oven, Technical & Service Manual

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Troubleshooting
3-12
Procedure
Letter
N
Component Test
RELAY 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.
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.
6. After that procedure, re-connect the power supply cord.
7. Remove the outer case and check voltage between Pin No. 1 of the 3 pin connector (A) and
the cabinet side terminal of the relay RY1 on the control unit with an A.C. voltmeter.
The meter should indicate 120 volts, if not check oven circuit.
RY1 and RY2 Relay Test
These relays are operated by D.C. voltage
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation.
DC. voltage indicated ----------------------------- Defective relay.
DC. voltage not indicated ------------------------ Check diode which is connected to the relay
coil. If diode is good, control unit is defective.
8. f any abnormal condition is defected, replace the control unit.
9. Disconnect the power supply cord and then remove outer case.
10. Open the door and block it open.
11. Discharge high voltage capacitor.
12. Reconnect all leads removed from components during testing.
13. Re-install the outer case (cabinet).
14. Reconnect the power supply cord after the outer case is installed.
15. Run the oven and check all functions.
RELAY SYMBOL OPERATIONAL VO LTAGE CONNECTED COMPONENTS
RY1 Approx. 24.0V D.C. Oven lamp / Fan motor / Stirrer motor
RY2 Approx. 24.0V D.C. Power transformer
RY4 Approx. 24.0V D.C. Hood motor (HIGH/MED selection)
RY5 Approx. 24.0V D.C. Hood motor (HIGH/MED/LOW selection)
RY6 Approx. 24.0V D.C. Hood motor
RY7, RY8, RY9 Approx. 24.0V D.C. Cook top lamp
RY3 Approx. 24.0V D.C. Turntable motor