Chapter 4 Troubleshooting Procedures; Introduction; Handling Precautions; Parts Replacement And Substitution - Motorola ASTRO Digital XTL 5000 Detailed Service Manual

Chapter 4 Troubleshooting Procedures

4.1

Introduction

This section will aid you in troubleshooting a malfunctioning XTL 5000 radio. It is intended to be
detailed enough to localize the malfunctioning circuit and isolate the defective component.
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C a u t i o n
4.2

Handling Precautions

Complementary metal-oxide semiconductor (CMOS) devices and other high-technology devices, are
used in the XTL 5000 radio. While the attributes of these devices are many, their characteristics
make them susceptible to damage by electrostatic discharge (ESD) 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 this radio, and are especially important in low-
humidity conditions. DO NOT attempt to disassemble the radio without observing the following
handling precautions.
1. Eliminate static generators (plastics, Styrofoam, etc.) in the work area.
2. Remove nylon or double-knit polyester jackets, roll up long sleeves, and remove or tie back
loose hanging neckties.
3. Store and transport all static-sensitive devices in ESD-protective containers.
4. Disconnect all power from the unit before ESD-sensitive components are removed or inserted
unless otherwise noted.
5. Use a static-safeguarded workstation, which can be accomplished through the use of an anti-
static kit (Motorola part number 01-80386A82). This kit includes a wrist strap, two ground
cords, a static-control table mat and a static-control floor mat.
6. Always wear a conductive wrist strap when servicing this equipment. The Motorola part
number for a replacement wrist strap that connects to the table mat is 42-80385A59.
4.2.1

Parts Replacement and Substitution

Special care should be taken to ensure that a suspected component is actually the one at fault. This
special care will eliminate unnecessary unsoldering and removal of parts, which could damage or
weaken other components or the printed circuit board (PCB) itself.
When damaged parts are replaced, identical parts should be used. If the identical replacement
component is not locally available, check the parts list for the proper Motorola part number and order
the component from the nearest Motorola Communications Parts facility.
Most of the ICs are static-sensitive devices. Do not attempt
to troubleshoot or disassemble a board without first referring
to the following Handling Precautions section.