SERWCING
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.
1) When storing and transporting, thoroughly wrap them in
aluminum foil.
Also wrap all PW boards containing them in aluminium
foil.
2) When soldering, ground the technician as shown in the
f ig ure and use grounded soldering iron and work table.
2.Shapes of Electronic Components
‘ransistor
2SB793
Transistor
DTD: 43EA
Transistor
DTAi 43ES
DTB’43ES
YRA102M
KRC f 021&
2SA933S
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 DUR-
ING SERVICING PRESENTS A HAZARD.
Therefore, when checking the performance of the touch con-
trol 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 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 properand 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 sen-
sor-related controls of the touch contra! panel by using
the dummy resistonsj.
4Servicing Toois
Toois required to service the touch control panel as-
sembly.
: I Soldering ITO:: SOW
j 11 IS recommended to use a soldering iron with a
grounding terminai.1
2>
CMiioscope: Single beam. frequency range: DC-
d 3MYz type 0:
more advanced model. 3jOthers:
r:aqd i:;gls
SIXher Precautions
7: ESeiore turning on the power source of the control
unit. remove the aluminum foil applied for preventing
static electricity.
Connect the connector of the key unit to the control
unit being sure tha? the lead wires are not twisted.
After aluminum foil is removed. be careful that ab-
normal voltage due to static electricity etc. is not
applied to ?he input or output terminals.
Attach connectors. electrolytic capacitors, etc. to
PWB, making sure that all connections are tight.
5) Be sure to use specified
precision is required.
components where high
To Next Page
Loading...
Need help?
General
