Maxon Telecom SP210 - Manual (Page 82)

Maxon SP200/210 Radio SP200/210
10. SPARE PARTS & MAINTENANCE POLICY - Issue 1.0
Page 10-2
03/01
10.1.1 Component Replacement
Surface mount components
Surface mount 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-layered
boards used in the radio.
With either soldering system, the component
manufacturer’s recommended temperature
should be maintained.
The following procedures outline the removal
and replacement of surface mount
components. If a hot-air soldering system is
employed, see the manufacturer’s operating
instructions for detailed information on the
use of your system.
CAUTION: Avoid applying heat to the body
of any surface mount component using
standard soldering method. Heat should be
applied only to the metalised 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: The CMOS integrated circuit
devices used in this equipment can be
destroyed by static discharges.
Before handling any of these devices,
service technicians should discharge
themselves by touching the case of a bench
test instrument that has a 3-prong power
cord connected to an outlet with a known
good earth ground.
When soldering or desoldering a CMOS
device, the soldering equipment should have
a known good earth ground.
Surface mount removal
1. Grip the component with tweezers
or sill needle nose pliers.
2. Alternately heat the metalised
terminal ends of the surface mount
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 soldering
equipment to prevent damage to the printed
circuit board (PCB) and the surrounding
components.
3. When the solder on all terminals is
liquefied, gently remove the component.
Excessive force may cause the PCB 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 solder wick. Again, use great care
when de- soldering or soldering on the
printed circuit boards.
It may be necessary to remove the epoxy
adhesive that was under the surface mount
component and any flux on the PCB.
Surface mount component replacement
1. “Tin” one terminal end of the new
component and the corresponding pad of the
PCB. Use as little solder as possible.
2. Place the component on the PCB
pads, observing proper orientation for
capacitors, diodes, transistors, 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 liquefies.
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, apply hot air until all
“tinned” areas are melted and the component
is seated in place. It may be necessary to
slightly press the component down on the
board.
Touch-up the soldered connections with a
standard soldering iron as needed. Do not
use excessive solder.
CAUTION: Some chemicals may damage
the internal and external plastic parts of the
radio.
4. Allow the component and the board
to cool and then remove all flux from the area
using alcohol or another approved flux
remover.