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

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Component Teardown
4-3
3. Servicing Tools
Tools required to service the touch control panel
assembly.
1) Soldering iron: 60W
(It is recommended to use a soldering iron with a
grounding terminal.)
2) Oscilloscope: Single beam, frequency range:
DC-10MHz type or more advanced model.
3) Others: Hand tools
4. Other Precautions
1) Before turning on the power source of the con-
trol unit, remove the aluminum foil applied for pre-
venting static electricity.
2) Connect the connectors 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.
Precautions for Using Lead-
Free Solder
1. Employing lead-free solder
The "Control unit PWB and Inverter unit PWB" of
this model employs lead-free solder. This is
indicated by the "LF" symbol printed on the PWB
and in the service manual. The suffix letter
indicates the alloy type of the solder.
Example:
2. Using lead-free wire solder
When repairing a PWB with the "LF" symbol, only
lead-free solder should be used. (Using
normal tin/lead alloy solder may result in cold sol-
dered joints and damage to printed patterns.) As
the melting point of lead-free solder is approxi-
mately 40 C higher than tin/lead alloy
solder, it is recommend that a dedicated bit is
used, and that the iron temperature is adjusted
accordingly.
3. Soldering
As the melting point of lead-free solder (Sn-Ag-
Cu) is higher and has poorer wettability, (flow), to
prevent damage to the land of the PWB, extreme
care should be taken not to leave the bit in con-
tact with the PWB for an extended period of time.
Remove the bit as soon as a good flow is
achieved. The high content of tin in lead free
solder will cause premature corrosion of the bit.
To reduce wear on the bit, reduce the
temperature or turn off the iron when it is not
required.
Leaving different types of solder on the bit will
cause contamination of the different alloys, which
will alter their characteristics, making good
soldering more difficult. It will be necessary to
clean and replace bits more often when using
lead-free solder. To reduce bit wear, care should
be taken to clean the bit thoroughly after each
use.
Sn-Ag-Cu
Indicates lead-free solder of tin, silver and copper.