Electrolux E30MO65GSSB, Technical & Service Manual

Page: 37 / 64

Troubleshooting and Testing
3-13
Procedure
Letter
Q
R
Component Test
KEY UNIT TEST
If the display fails to clear when the STOP/CLEAR pad is depressed, first verify the flat ribbon cable
is making good contact, verify that the door sensing switch (stop switch) operates properly; that is
the contacts are closed when the door is closed and open when the door is open. If the door sens-
ing switch (stop switch) is good, disconnect the flat ribbon cable that connects the key unit to the
control unit and make sure the door sensing switch is closed (either close the door or short the door
sensing switch connector). Use the key unit matrix indicated on the control panel schematic and
place a jumper wire between the pins that correspond to the STOP/CLEAR pad making momentary
contact.
If the control unit responds by clearing with a beep the key unit is faulty and must be replaced. If the
control unit does not respond, it is a faulty and must be replaced. If a specific pad does not respond,
the above method may be used (after clearing the control unit) to determine if the control unit or key
pad is at fault.
RELAY TEST
1. Remove outer case and check voltage between Pin Nos. 7 and 9 of the 9- pin connector (A)
on the control unit with an A.C. voltmeter. The meter should indicate 120 volts, if not check the
oven circuitry.
Shut-off, Cook and Heater 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 or convection 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.
2. Disconnect the power supply cord.
3. Open the door and block it open.
4. Discharge high voltage capacitor.
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.