LBI-33057
16
Troubleshooting details on the other assemblies lo-
cated in the Front Cover Assembly can be found LBI-
38834. These assemblies include the LCD Board and the
various flex circuits used in the radio.
COMPONENT REPLACEMENT
SURFACE MOUNTED COMPONENTS
Surface mounted "chip" components should always
be replaced using a temperature-controlled soldering
system. The soldering
tools may be either a temperature-
controlled soldering iron or a temperature-controlled hot-
air soldering station. A hot-air system is recommended
for the removal of components on the multi- layer boards
utilized throughout the radio. With either soldering sys-
tem, at a temperature of 700°F (371°C) should be main-
tained.
The following procedures outline the removal and
replacement of surface mounted components. If a hot- air
soldering system is employed, see the manufacture's op-
erating instructions for detailed information on the use of
your system.
Avoid applying heat to the body of any chip
component when using standard soldering
methods. Heat should be applied only to the
metallized terminals of the components. Hot-air
systems do not damage the components since the
heat is quickly and evenly distributed to the
external surface of the component
CAUTION
As the radio contains many static sensitive
components, observe static handling precautions
during all service procedures.
CAUTION
SURFACE MOUNTED COMPONENT
Removal
1. Grip the component with tweezers or small nee-
dle-nose pliers.
2. Alternately heat the metallized terminal ends of
the component with the soldering iron. If a hot-
air system is used, direct the heat to the terminals
of the component. Use extreme care with the sol-
dering equipment to prevent damage to the
printed wire board (PWB) and the surrounding
components.
3. When the solder on all terminals is liquefied,
gently remove the component. Excessive force
may cause the PWB pads to separate from the
board if all solder is not completely liquefied.
4. It may be necessary to remove excess solder using
a vacuum de-soldering tool or Solderwick
.
Again, use great care when de-soldering or sol-
dering on the printed wire boards. It may also be
necessary to remove the epoxy adhesive that was
under the component.
SURFACE MOUNTED COMPONENT
Replacement
1. "Tin" one terminal end of the new component
and the corresponding pad on the PWB. Use as
little solder as possible.
2. Place the component on the PWB pads, observing
proper orientation for capacitors, diodes, transis-
tors, etc.
3. Simultaneously touch the "tinned" terminal end
and the "tinned" pad with the soldering iron.
Slightly press the component down on the board
as the solder is liquefied. Solder all terminals,
allowing the component time to cool between
each application of heat. Do not apply heat for an
excessive length of time and do not use excessive
solder.
With a hot-air system, "tin" all terminals and
apply heat until all "tinned" areas are melted and
the component is seated in place. It may be nec-
essary to slightly press the component down on
the board. Touch-up the soldered connections
with a standard soldering iron if needed. Do not
use excessive solder.
4. Allow the component and the board time to cool
and then remove all flux from the area using al-
cohol or another approved flux remover.
Some chemicals may damage the internal and
external plastic and rubber parts of the radio.
CAUTION
