Specifications

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
VHF synthesized mobile radio. With either soldering system, a temperature of 700ø F (371ø C) 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 methods.
Heat should be applied only to the metalized 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 one 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 small needle nose pliers.
2. Alternately heat the metalized 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 also be necessary to remove
the epoxy adhesive that was under the surface mount component and any flux on the printed circuit board.
MONOGRAM SERIES LBI-38864B
COMPONENT REPLACEMENT
Page -29-
Nov. 94