Electrolux EI30BM55HB - 30" Microwave Oven, Техническое и сервисное руководство

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Troubleshooting
3-10
Procedure
Letter
L
Component Test
TOUCH CONTROL PANEL ASSEMBLY TEST
The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc.
Therefore, unlike conventional microwave ovens, proper maintenance cannot be performed with
only a voltmeter and ohmmeter.
In this service manual, the touch control panel assembly is divided into three units, Control Unit,
Keyboard Unit and Power Unit, and troubleshooting by unit replacement is described according
to the symptoms indicated.
Before testing,
1) Disconnect the power supply cord, and then disassemble as per “HOOD LOUVER
REMOVAL”, “REMOVAL OF OVEN FROM WALL” and “OUTER CASE REMOVAL”.
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.
1. Keyboard Unit
1) Check Keyboard glass unit connection before replacement.
2) Reconnect all leads removed from components during testing.
3) Re-install the covers.
4) Reconnect the power supply cord after the covers are installed.
5) Run the oven and check all functions.
The following symptoms indicate a defective keyboard 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.
If the keyboard unit is defective.
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) Replace the door frame assembly.
5) Reconnect all leads removed from components during testing.
6) Re-install the covers.
7) Reconnect the power supply cord after the covers are installed.
8) Run the oven and check all functions.
2. Control Unit.
The following symptoms indicate a defective control unit. Before replacing the control unit, per-
form the Keyboard glass unit test (Procedure M) to determine if control unit is faulty.
1) In connection with indicators
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) The figure of all digits flicker.