VT220

This document is a pocket service guide for the Digital Equipment Corporation VT220 video terminal, covering models A, B, C, D, E, and F. It provides essential information for servicing the terminal, including detailed procedures for testing and troubleshooting various components and functions.

Key areas covered in the guide include:

• Testing and Troubleshooting: This section outlines self-tests for power-up, EIA port data lines, printer port, EIA port control lines, and 20 mA port loopback. It also includes a screen alignment test and troubleshooting steps for VT22X modem option problems, printer issues, and general problems, along with error codes and corrective actions.
• Removing and Replacing FRUs (Field Replaceable Units): Separate chapters detail the removal and replacement procedures for FRUs (e.g., access cover, terminal controller board, power supply/monitor board, flyback transformer, CRT assembly, keyboard, and VT22X modem option) for models A, B, C and the differing procedures for models D, E, F.
• Video Monitor Alignment: Instructions are provided for aligning the VT220 monitor, covering adjustments for character quality (brightness, contrast, vertical linearity, focus), horizontal hold, display centering, and display size (horizontal width, vertical height).
• Set-Up Reference Material: This section refers to the VT220 Owner's Manual for set-up summaries and explains how to use and save/recall set-up values.
• Appendices: Additional information includes VT220 documentation, FRU exploded view drawings for different models, cable information (interface cables and modem control selections), and physical/functional diagrams of the terminal's internal components.

The guide emphasizes safety warnings, cautions, and notes throughout, particularly regarding high voltage components. It also lists required tools and recommended spare parts for each model series.