Chapter 1 Introduction
1.1 General
This manual includes all the information needed to maintain peak product performance and 
maximum working time for the ASTRO APX 1000 radio. This detailed level of service (component 
level) is typical of the service performed by some service centers, self-maintained customers, and 
distributors.
Use this manual in conjunction with the APX 1000 VHF (136–174 MHz), UHF1 (380–470 MHz), 
UHF2 (450–520 MHz) and 700/800 MHz (764–870 MHz) Digital Portable Radios Basic Service 
Manual (Motorola part number 68012004056), which can help in troubleshooting a problem to a 
particular printed circuit (PC) board.
Conduct the basic performance checks outlined in the basic service manual first to verify the need to 
analyze the radio and to help pinpoint the functional problem area. In addition, you will become 
familiar with the radio test mode of operation, which is a helpful tool. If any basic receive or transmit 
parameters fail to be met, the radio should be aligned according to the radio alignment procedure.
Included in other areas of this manual are functional block diagrams, detailed theory of operation, 
troubleshooting charts and waveforms, schematics, and parts lists. You should become familiar with 
these sections to aid in determining circuit problems. Also included are component location diagrams 
to aid in locating individual circuit components and some IC diagrams, which identify some 
convenient probe points.
“Chapter 3, Theory of Operation,”, contains detailed descriptions of the operations of many circuits. 
Once you locate the problem area, review the troubleshooting flowchart for that circuit to fix the 
problem.