5-2 Disassembly/Reassembly Procedures Safe Handling of CMOS and LDMOS Devices
Cleaning External Plastic Surfaces
Apply the 0.5% detergent-water solution sparingly with a stiff, non-metallic, short-bristled brush to
work all loose dirt away from the radio. Use a soft, absorbent, lintless cloth or tissue to remove the
solution and dry the radio. Make sure that no water remains entrapped near the connectors, cracks,
or crevices.
Cleaning Internal Circuit Boards and Components
Isopropyl alcohol (100%) may be applied with a stiff, non-metallic, short-bristled brush to dislodge
embedded or caked materials located in hard-to-reach areas. The brush stroke should direct the
dislodged material out and away from the inside of the radio. Make sure that controls or tunable
components are not soaked with alcohol. Do not use high-pressure air to hasten the drying process
since this could cause the liquid to collect in unwanted places. After completing of the cleaning
process, use a soft, absorbent, lintless cloth to dry the area. Do not brush or apply any isopropyl
alcohol to the frame, front cover or back cover.
5.3 Safe Handling of CMOS and LDMOS Devices
Complementary Metal Oxide Semiconductor (CMOS) and Laterally Diffused Metal Oxide
Semiconductor (LDMOS) devices are used in this family of radios, and are susceptible to damage by
electrostatic or high voltage charges. Damage can be latent, resulting in failures occurring weeks or
months later. Therefore, special precautions must be taken to prevent device damage during
disassembly, troubleshooting, and repair.
Handling precautions are mandatory for CMOS/LDMOS circuits and are especially important in low
humidity conditions.
NOTE
Always use a fresh supply of alcohol and a clean container to prevent contamination by
dissolved material (from previous usage).
Use all chemicals as prescribed by the manufacturer. Be sure
to follow all safety precautions as defined on the label or
material safety data sheet.
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