TM 11-5820-922-40-1
8.
Remove the board from the oven and
6.
Using an X-acto knife, very care-
allow it to cool to room temperature.
fully cut down into the wire just at, or
Remove the clamp(s).
ahead of, the point where it emerges
from the solder.
REPAIR OF DEFECTIVE PLATED-
THROUGH HOLE. Defective plated-through
holes can be repaired by performing the
NOTE
following steps.
The wire shall not extend past
NOTE
the periphery of the pad to
which it is soldered.
If there should be a component
placed in such a manner as to
interfere with the performance
7.
Grasp the free end of the wire and
of this repair, remove that
lift it slowly so that it separates at
component according to the
the cut produced in step 6.
procedure contained in para-
graph 3-27 or paragraph 3-28.
Handle this removed component
8.
Turn the circuit card over and
with care because it may be
repeat steps 6 and 7 for the other side
reinstalled upon the com-
of the repair.
pletion of this repair.
1.
9. Apply a small amount of soldering
Cut a length of 34-gage uninsu-
lated tin-coated wire from 50 to 100
flux to each side of the repair, and
millimeters (2 to 4 inches) long and
using the soldering iron touch up the
solder joints to cover any of the copper
pass it through the defective plated-
wire exposed by the trimming of the
through hole. If the wire will not pass
leads.
through the hole, due to solder
build-up, the hole may be cleared with
the use of a vacuum resoldering unit.
WARNING
2.
Hold one end of the wire against
Isopropyl alcohol is flammable.
one side of the circuit card and pull
the other end taut and down against the
Keep away from heat and open
flame. Vapors may be harmful.
other side of the circuit card, being
careful to avoid aligning the wire with
Use with adequate ventilation.
Avoid prolonged or repeated
any circuit traces emerging from the pad.
breathing of vapor. Avoid eye
contact. Do not take
3.
Turn the circuit card over and
repeat step 2 for the opposite side.
internally.
4.
Using solder, the soldering iron,
10.
Clean the repaired area with
to the pad using a minimum amount of
isopropyl alcohol.
solder.
5. Turn the circuit card over and
11.
If a component has been removed in
repeat step 4 as required.
order to accomplish this repair, and if
it is visually and mechanically sound,
CAUTION
replace that component according to the
procedure in paragraphs 3-30, 3-31, or
Do not cut down into the cir-
3-32. If the component is defective,
cuit card pad when trimming the
replace it with an identical new
wire.
component.
