TM 11-5820-922-40-1
solder has melted, in and around the
REMOVAL OF SOLDERED COMPONENTS
lead hold, quickly remove the solder
HAVING AXIAL LEADS. Components with
with the solder-removing tool. Repeat
axial leads that are soldered in place
this procedure for each lead associated
on the circuit card may be removed by
with the component to be removed.
performing the following steps:
2. Remove the component from the
1.
Use diagonal cutting pliers to cut
circuit card.
the leads of the component part close to
the component. Carefully straighten the
3-29. REMOVAL OF TRANSISTORS.
The
end that extends through each hole so
transistor connection points in a given
that the lead may be easily withdrawn.
circuit may not be keyed. Therefore,
when replacing a transistor, it is pos-
2. Use a vacuum resoldering unit, if
sible to insert the replacement transis-
available, to remove the solder from
tor backwards to reversing the emitter
each lead on the component. If a vacuum
and collector leads. For this reason,
resoldering unit is not available, exert
before the transistor is unsoldered from
a slight pressure and apply the tip of
the circuit, identify the emitter and
the soldering iron to the tip of the
collector terminals in the circuit.
lead. Keep the soldering iron away from
Mark the emitter terminal connection
the circuit etch. As the lead end
absorbs heat, the solder will melt and
point in the circuit with a pencil, a
piece of chalk, or a crayon before
the lead will break away from its junc-
removing the transistor. The transistor
tion with the circuit etch. Remove the
soldering iron immediately and quickly
may then be removed.
pull the lead free. Use the solder-
removing tool to remove excess solder.
SOLDERED COMPONENT REPLACEMENT.
Do not force or twist the lead to remove
Horizontally mounted components rated at
it from the circuit card.
less than 1 watt and with pigtail leads
which are inserted in plated-through
3. Remove the component from the
eyelets or in unsupported holes should
be mounted flush with the board surface.
circuit card.
Components rated at 1 watt or more
REMOVAL OF SOLDERED COMPONENTS
should be mounted with 1/16-inch
clearance between the component and the
HAVING RADIAL LEADS. Components with
surface of the board.
radial leads that are soldered in place
on the circuit card may be removed by
the procedure described in paragraph
COMPONENT REPLACEMENT IN EYELETS.
Components may be replaced in circuit
3-29 if the leads are accessible on the
component side of the circuit card. If
cards which have eyelets by performing
the following steps:
the leads of the component are not
accessible on the component side of the
circuit board, the component may be
NOTE
removed by performing the following
steps:
See paragraph 3-30 for compo-
nent clearance requirements.
1.
Use a vacuum resoldering unit, if
1.
Make certain that all the poly-
available, to remove the solder from
each lead on the component. If a vacuum
urethane coating has been removed from
the pads on both sides of the circuit
resoldering unit is not available, exert
a slight pressure and apply the tip of
card.
the soldering iron to the tip of the
2.
lead. Keep the soldering iron away from
Apply the well-tinned tip of the
soldering iron as close as possible to
the circuit etch. As the lead absorbs
heat, the solder will melt. When the
the eyelet-component lead intersection.
