Electrolux E30MO65GSSA Service Manual page 30

E30MO65GSSA
1. Precautions for Handling Electronic Components
This unit uses CMOS LSI in the integral part of the circuits.
When handling these parts, the following precautions
should be strictly followed. CMOS LSI have extremely
high impedance at its input and output terminals. For this
reason, it is easily influenced by the surrounding high
voltage power source, static electricity charge in clothes,
etc, and sometimes it is not fully protected by the built-in
protection circuit.
In order to protect CMOS LSI.
) When storing and transporting, thoroughly wrap them in
aluminium foil. Also wrap all PW boards containing them
in aluminium foil.
2) When soldering, ground the technician as shown in the
figure and use grounded soldering iron and work table.
2. Shapes of Electronic Components
B
C
E
Transistor
2SB90M
3. Servicing of Touch Control Panel
We describe the procedures to permit servicing of the
touch control panel of the microwave oven and the
precautions you must take when doing so. To perform the
servicing, power to the touch control panel is available
either from the power line of the oven itself or from an
external power source.
(1) Servicing the touch control panel with power supply
of the oven:
CAUTION:
THE HIGH VOLTAGE TRANSFORMER OF THE
MICROWAVE OVEN IS STILL LIVE DURING SERVICING
PRESENTS A HAZARD.
Therefore, when checking the performance of the touch
control panel, put the outer cabinet on the oven to
avoid touching the high voltage transformer, or unplug
the primary terminal (connector) of the high voltage
transformer to turn it off; the end of such connector must
be insulated with an insulating tape. After servicing, be
sure to replace the leads to their original locations.
A. On some models, the power supply cord between the
touch control panel and the oven itself is so short that
the two can't be separated.
For those models, check and repair all the controls
(sensor-related ones included) of the touch control panel
approx. 1M ohm
Transistor
DTA23ES
KRA0M
KRA223M
C B
KRC243M
E
SERVICING
while keeping it connected to the oven.
B. On some models, the power supply cord between the
touch control panel and the oven proper is long enough
that they may be separated from each other. For those
models, therefore, it is possible to check and repair
the controls of the touch control panel while keeping it
apart from the oven proper; in this case you must short
both ends of the door sensing switch (on PWB) of the
touch control panel with a jumper, which brings about
an operational state that is equivalent to the oven door
being closed. As for the sensor-related controls of the
touch control panel, checking them is possible if dummy
resistor(s) with resistance equal to that of the controls
are used.
(2) Servicing the touch control panel with power supply
from an external power source:
Disconnect the touch control panel completely from the
oven proper,and short both ends of the door sensing
switch (on PWB) of the touch control panel,which brings
about an operational state that is equivalent to the oven
door being closed. Connect an external power source
to the power input terminal of the touch control panel,
then it is possible to check and repair the controls of
the touch control panel it is also possible to check the
sensor-related controls of the touch control panel by
using the dummy resistor(s).
4. Servicing Tools
Tools required to service the touch control panel
assembly.
) Soldering iron: 30W
(It is recommended to use a soldering iron with a grounding
terminal.)
2) Oscilloscope: Single beam, frequency range: DC - 0MHz
type or more advanced model.
3) Others: Hand tools
5. Other Precautions
) Before turning on the power source of the control unit,
remove the aluminum foil applied for preventing static
electricity.
2) Connect the connector of the key unit to the control unit
being sure that the lead wires are not twisted.
3) After aluminum foil is removed, be careful that abnormal
voltage due to static electricity etc. is not applied to the
input or output terminals.
4) Attach connectors, electrolytic capacitors, etc. to PWB,
making sure that all connections are tight.
5) Be sure to use specified components where high precision
is required.
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