About this Manual Purpose This service guide contains reference information for the Extensa 670 computer. It gives the system and peripheral specifications, shows how to identify and solve system problems and explains the procedure for removing and replacing system components. It also gives information for ordering spare parts. Manual Structure This service guide consists of six chapters and one appendices as follows: Chapter 1 General Description This chapter contains a general overview of the system, describes the standard and optional features, and identifies the major assemblies and subassemblies. This section also contains detailed functional and environmental specifications. Chapter 2 Installation This chapter contains unpacking and preparation for use instructions for the system. Chapter 3 Operating Instructions This chapter contains a summary of Notebook operating procedures useful for maintenance operations. Chapter 4 Theory of Operation This chapter contains a general block diagram theory of operation description and major chips introductions. Chapter 5 Troubleshooting Procedures This chapter contains an overview of the fault isolation process, provides guidelines for isolating 67x series computer malfunctions to replaceable subassemblies and provides instructions for executing diagnostics and interpreting error messages. Chapter 6 Field Service This chapter contains the machine disassembly and unit replacement information. Appendix A Maintenance Data This appendix contains the FRU information, jumper settings information and schematic diagrams of the system.