Barclays Branch Controller Maintenance Guide (Mk III)

This document is the Maintenance Guide for the Barclays Branch Controller MKIII, published in March 1985 by Digital Equipment Company Ltd. It provides comprehensive instructions for diagnosing, troubleshooting, and replacing hardware components (Field-Replaceable Units or FRUs) of the controller.

Key information includes:

• System Diagnostics: How to run power-up diagnostics, interpret LED codes for FRU failures, and use different keyswitch positions (NORMAL, TEST, AUX).
• FRU Replacement: Step-by-step procedures for accessing and replacing various circuit boards (e.g., KDJ11-B, MSV11-PL, KMV11-B), disk drives (RD52, RX50), and power supply units, including necessary jumper/switch settings.
• Physical Access: Instructions for cover removal and accessing the controller within its rack.
• Software Loading: Guidance on loading Barclays application software onto replacement drives.
• Fault Reporting: Procedures and contact information for reporting system defects.
• Component Lists: A complete list of all field-replaceable units.

The guide is intended for personnel responsible for the upkeep and repair of this specific banking system hardware.