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Excessive heat or pressure can lift the copper strip from the board. Avoid damage by using a
low power soldering iron (50 watts maximum) and following these instructions. Coppeq that lifts
off the board should be cemented in place with a quick drying acetate base cement having good
electrical insulating properties.
A break in the copper should be repaired by soldering a short length of tinned copper wire
across the break.
Use only high quality rosin core solder when repairing etched circuit boards.
NEVER
USE
PASTE
FLUX.
After soldering, clean off any excess flux and coat the repaired area with a
high quality electrical varnish
or
lacquer.
When replacing components with multiple mounting pins suchas tube sockets, electrolytic capa-
citors, and potentiometers, it will be necessary to lift each pin slightly, working around the
components several times until it is free.
WARNING: If the specific instrnctions outlinedinthe steps below regarding etched circuit boards
without eyelets a r e not followed, extensive damage to the etched circuit board w i l l result.
1. Apply heat sparingly to lead of component
2. Reheat solder in vacant eyelet and quickly
to be replaced. If lead of component passes
insert a small awl to clean inside of- hole.
through an eyelet
If hole does
.........
in the circuit
.................
board, apply
heat on com-
ponent side
of
board. If
from con-
lead of com-
ponent does
of board.
not p a s s r o u g h .an
-
eyelet, apply Heat to conductor side
of
board.
4.
Hold part against board (avoid overheating)
3. Bend clean tinned lead on new part and
and solder leads.
carefullyinsert
-
Apply heat to compo-
through eyelets or
nent leads on correct
holes in board.
side
of
board
a s explained
in step 1.
In the event that either the circuit board has been damaged o r the conventional method i s imprac
-
tical, use method shown below. Thisis especially applicablefor circuit boards without eyelets.
1 . Clip lead a s shown below.
2. Bend protruding leads upward. Bend 1
of new
APPLY
CLIP
component
SOLDER
HERE
around pro-
truding lead.
Apply solder
using a pair
of long nose pliers a s a heat sink.
This procedure is used in the field only a s an alternate means of repair.
It is not used within
the factory.
d
Figure
5-6.
Servicing Printed Wiring
Boards
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