Motorola Astro Dimetra MTP, Instruction Manual

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Alcohol is a high-wetting liquid, and can carry contamination
into unwanted places if an excessive quantity is used. Make sure
that the controls are not soaked with the liquid. When the
cleaning process is complete, use a soft, absorbent, lintless cloth
to dry the area.
Note: Always use a fresh supply of alcohol and a clean
container to prevent contamination by dissolved
material from previous usage.
5. Reassemble the console, reversing the disassembly procedure.
Corrective
Maintenance
Introduction
Efficient corrective maintenance requires an orderly and logical
troubleshooting procedure for identifying and locating malfunctions
in the XTVA’s internal or external circuits. Troubleshooting and repair
will be greatly simplified by becoming familiar with the overall XTVA
and portable radio operation.
This section provides detailed information required to isolate
malfunctions to the XTVA’s internal or external circuits. The
troubleshooting chart at the end of this section provides information
on possible circuit failures and related symptoms, and probable
malfunctioning stages.
Generally, if the XTVA is totally inoperative, it may be assumed that
the vehicle’s battery is completely discharged, the fuse is blown, or the
power lead is opened. However, if the XTVA is partially operative, it
may be assumed that the batteries are serviceable and that one or more
internal or external functional XTVA circuits are defective or marginal.
Using diagrams, the troubleshooting chart, the voltage table, and
deductive reasoning, the defective circuit may readily be found.
To further aid in analyzing the symptoms and possible causes of the
malfunction, check: RF power output (using an in-line wattmeter),
audio deviation, and current drain. Once the general problem area of
the XTVA is identified, careful use of a dc voltmeter, ohmmeter, and/
or oscilloscope should help isolate the problem to a defective
component.
Test Equipment and
Service Aids
Table 4, “Recommended Test Equipment,” lists the bench test
equipment recommended to properly service the XTVA. Refer to the
appropriate portable radio’s service manual for the recommended
radio test equipment. For field servicing, the vehicle’s battery is an
adequate power source. Battery-operated test equipment is
recommended when available.