Professional 380 Pocket Service Guide

This document is a "Pocket Service Guide" for the Digital Equipment Corporation Professional 380 computer system (with some references to Professional 325/350 models). Issued by Granada Computer Services (UK) Limited's Training Department in 1984/1986, it is explicitly marked "FOR REFERENCE ONLY NOT MAINTAINED," indicating its outdated and unsupported status.

The guide's primary purpose is to assist technicians in:

• Troubleshooting and Testing: Providing procedures and error codes to diagnose system issues down to the Field Replaceable Unit (FRU) level, utilizing internal self-tests and dedicated maintenance application diskettes. This includes tests for various components like the system unit, keyboard, printer, configuration display, disk drives, and optional units (CP/M, Real-Time Interface, Telephone Management System, DECNA Controller, Analog Data Module, Hard Disk Expander, Serial Line Unit).
• Removal and Replacement: Detailing step-by-step instructions for disassembling the system and replacing FRUs such as the top cover, diskette drives, hard disk drives, various circuit boards (motherboard, I/O boards, memory boards), power supply, battery pack, and specific option components. A recommended spares list is included.
• Video Monitor Alignment: Offering guidelines for adjusting and aligning the monochrome monitor (VR201), including vertical hold, horizontal hold, focus, centering, aspect ratio, and linearity.
• DELNI Unit Testing and Troubleshooting: Providing specific procedures for diagnosing issues with the Digital Ethernet Local Network Interconnect (DELNI) unit and its transceiver cables.

The document also lists required tools and references related technical documentation and exploded view drawings of FRUs.