VT320 Pocket

This document serves as a service guide for Digital Field Service personnel for the VT320 monochrome video terminal, published in July 1987. It covers a comprehensive range of topics essential for servicing the terminal, including troubleshooting, repair, and maintenance.

The guide is structured into several key areas:

1. Testing and Troubleshooting: Details general problem diagnosis using flowcharts, performing various self-tests (power-up, loopback tests for RS232, DEC-423, and printer ports), addressing common printer issues, and interpreting error codes for fault isolation. These tests often require specific loopback connectors and setting the terminal to "Local" and "VT100 Mode."
2. Removing and Replacing Field Replaceable Units (FRUs): Provides step-by-step procedures for replacing major components such as the access cover, power supply assembly, CRT/bezel/yoke assembly, monitor and logic board with arc protection, and the keyboard. Emphatic warnings are included for handling high voltages, particularly during CRT removal and the specialized disposal process, which mandates specific safety gear and procedures for Digital personnel only.
3. Aligning the Video Monitor: Outlines detailed adjustments for the display, including screen control, subcontrast, rotation, horizontal width, vertical height, vertical linearity, centering, and focus. These adjustments typically involve using a screen test pattern of uppercase "E"s.
4. Using Set-Up: Offers a brief overview of the terminal's set-up utility, explaining how to display set-up screens, change settings (action fields vs. parameter fields), and save or recall different configurations (factory defaults or user-saved settings).

Appendices provide additional crucial information, such as orderable options and related documentation (modems, cables, other manuals), a detailed list of VT320 models (North American, International, and Custom versions with varying screen colors and power requirements), and recommended spare parts. A technical documentation change notice indicates updates to the Appendix B regarding models and notes on arc protection circuitry. Physical and functional diagrams of connectors and internal layouts are also included.