Chapter 8 Disassembly/Reassembly Procedures; Introduction; Replacement Procedures; Table 8-1. Required Alignments After Board Replacement - Motorola ASTRO SPECTRA Service Manual

Chapter 8 Disassembly/Reassembly Procedures

8.1

Introduction

This section details the procedures necessary to remove and replace the printed circuit boards in the
ASTRO Digital Spectra and Digital Spectra Plus radios. After troubleshooting and determining which
board needs to be replaced, disconnect the test equipment, the antenna cable, and unhook the dc
power.
! !
W A R N I N G
Locate the exploded view drawing of the radio in
it handy for reference when disassembling and reassembling the radio.
When installing a new circuit board, all mounting screws should be started before any are torqued.
This helps assure proper board alignment with the chassis.
After installing a new board, refer to
the replaced board.
Board Replaced
Command Board
VCO (Voltage Controlled
Oscillator)
RF (Radio Frequency) Board
PA (Power Amplifier) Board
VOCON Board
8.2

Replacement Procedures

NOTE: After performing alignment procedures, always exit the SERVICE menu entirely (to the MAIN
MENU) to save all changes properly. Failure to do so can result in a alignment (or other)
failure.
Disconnect all dc power to the radio before removing any
boards from the radio. Failure to remove power can result
in unit damage caused by transients or accidental shorts,
as well as a shock hazard.
Table 8-1

Table 8-1. Required Alignments After Board Replacement

Reference
Oscillator
X
X
X
Chapter 11: Exploded Views and Parts Lists
and perform the alignment procedures indicated for
Alignment Required
Transmit
Deviation Transmit
Balance Deviation
(compen- Limit
sation)
X X
X X
X X
. Keep
Transmit
Transmit
Current
Power
Limit
X X
X X