Electrolux E30MO75HSS Technical & Service Manual page 32

Troubleshooting and Testing
Procedure
Letter
NOISE FILTER TEST
O
1. Disconnect power supply cord, and 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. Using an ohmmeter, check between the terminals as
described in the table below. If incorrect readings are
obtained, replace the noise filter.
6. Reconnect all leads removed from components during testing.
7. Reinstall the outer case (cabinet).
8. Reconnect power supply cord after the outer case is installed.
9. Run oven and check all functions.
MEASURING POINT
Between N and H
Between terminal N and GRAY
Between terminal H and RED
P TOUCH CONTROL PANEL ASSEMBLY TEST
The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc.
Unlike conventional microwave ovens, proper maintenance cannot be performed with only a volt-
meter and ohmmeter. The touch control panel assembly is divided into two units, Control Unit and
Key Unit and troubleshooting by unit replacement is described according to the symptoms indicated.
1. Key Unit
The following symptoms indicate a defective key unit. Replace the key unit.
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.
2. Control Unit. The following symptoms indicate a defective control unit. Replace the control unit.
A. In connection with pads.
B. In connection with indicators
C. Other possible troubles caused by defective control unit.
Note: When defective components, the Control Unit or Key Unit are replaced, the defective part or
parts must be properly packed for return in the shipping carton, with its cushion material, in
which the new replacement part was shipped to you.
INDICATION OF OHMMETER
Open circuit.
Short circuit.
Short circuit.
Note: Check key unit ribbon connection before replacement.
a) When touching the pads, a certain group of pads do not produce a signal.
b) When touching the pads, no pads produce a signal.
a) At a certain digit, all or some segments do not light up.
b) At a certain digit, brightness is low.
c) Only one indicator does not light.
d) The corresponding segments of all digits do not light up; or they continue to light up.
e) Wrong figure appears.
f) A certain group of indicators do not light up.
g) All digits in the figure flicker.
a) Buzzer does not sound or continues to sound.
b) Clock does not operate properly.
c) Cooking is not possible.
d) Proper temperature measurement is not obtained.
Component Test
3-10
NOISE FILTER
N H
FUSE 20A
NOISE SUPPRESSION COIL
LINE CROSS CAPACITOR
0.22µF / AC 250V
LINE BYPASS LINE BYPASS
CAPACITOR CAPACITOR
0.0033µF / AC 125V 0.0033µF / AC 125V
GRY RED