Chapter 3 Maintenance; Introduction; Preventive Maintenance; Inspection - Motorola CDM1550 LS+ Detailed Service Manual

3-1
Chapter 3
Maintenance
3.1 Introduction
This chapter of the manual describes:
Preventive maintenance
Safe handling of CMOS and LDMOS devices
Repair procedures and techniques
3.2 Preventive Maintenance
The radios do not require a scheduled preventive maintenance program, however, periodic visual
inspection and cleaning is recommended.
3.2.1 Inspection
Check that the external surfaces of the radio are clean, and that all external controls and switches are
functional. It is not recommended to inspect the interior electronic circuitry.
3.2.2 Cleaning
WARNING
The following procedures describe the recommended cleaning agents and the methods to be used
when cleaning the external and internal surfaces of the radio. External surfaces include the front
cover, housing assembly, and battery case. These surfaces should be cleaned whenever a periodic
visual inspection reveals the presence of smudges, grease, and/or grime.
Note: Internal surfaces should be cleaned only when the radio is disassembled for
servicing or repair.
The only recommended agent for cleaning the external radio surfaces is a 0.5% solution of a mild
dishwashing detergent in water. The only factory recommended liquid for cleaning the printed circuit
boards and their components is isopropyl alcohol (70% by volume).
CAUTION: The effects of certain chemicals and their vapors can have harmful results on cer-
tain plastics. Aerosol sprays, tuner cleaners, and other chemicals should be avoided.
Cleaning External Plastic Surfaces
The detergent-water solution should be applied sparingly with a stiff, non-metallic, short-bristled brush
to work all loose dirt away from the radio. A soft, absorbent, lintless cloth or tissue should be used 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 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