Service manual

Chapter 2 Maintenance
2.1 Introduction
This chapter provides details about the following:
• Preventive Maintenance
• Safe Handling of CMOS and LDMOS Devices
• General Repair Procedures and Techniques
• Disassembling and Reassembling the Radio
2.2 Preventive Maintenance
The radio does not require a scheduled preventive maintenance program; however, periodic visual
inspection and cleaning is recommended.
2.2.1 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.
2.2.2 Cleaning Procedures
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 service or repair.
The only recommended agent for cleaning external radio surfaces is a 0.5% solution of a mild
dishwashing detergent in water. The only factory recommended liquid for cleaning printed circuit
boards and their components is isopropyl alcohol (70% by volume).
2.2.2.1 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.
2.2.2.2 Cleaning Internal Circuit Boards and Components
Apply Isopropyl alcohol (70%) 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 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.
CAUTION: The effects of certain chemicals and their vapors can have harmful results on certain
plastics. Avoid using aerosol sprays, tuner cleaners, and other chemicals.