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CAUTION: Work quickly to avoid overheating the circuit board printed foil.
1) Use the following unsoldering technique
a. Allow the soldering iron tip to reach normal temperature. (500
b. First, hold the soldering iron tip and solder the strand against the component lead until the
solder melts.
c. Quickly move the soldering iron tip to the junction of the component lead and the printed
circuit foil, and hold it there only until the solder flows onto and around both the component
lead and the foil.
CAUTION: Work quickly to avoid overheating the circuit board printed foil.
d. Closely inspect the solder area and remove any excess or splashed solder with a small
wire-bristle brush.
Remove /Replacement
Some chassis circuit boards have slotted holes (oblong) through which the IC leads are inserted and
then bent flat against the circuit foil. When holes are of slotted type, the following technique should
be used to remove and replace the IC. When working with boards using the familiar round hole, use
the standard technique as outlined.
Removal
Desolder and straighten each IC lead in one operation by gently prying up on the lead with the
soldering iron tip as the solder melts.
Draw away the melted solder with an anti-static suction-type solder removal device (or with solder
braid) before removing the IC.
Replacement
Carefully insert the replacement IC in the circuit board.
Carefully bend each IC lead against the circuit foil pad and solder it.
Clean the soldered areas with a small wire-bristle brush. (It is not necessary to reapply acrylic
coating to the areas).
"Small-Signal" Discrete Transistor
Removal/Replacement
Remove the defective transistor by clipping its leads as close as possible to the component body.
Bend into a "U" shape the end of each of three leads remaining on the circuit board.
Bend into a "U" shape the replacement transistor leads.
Connect the replacement transistor leads to the corresponding leads extending from the circuit board
and crimp the "U" with long nose pliers to insure metal to metal contact then solder each connection.
Power Output, Transistor Device
Removal/Replacement
Heat and remove all solder from around the transistor leads.
Warning and Cautions
o
F to 600
8
o
F)
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