LQP02 Printer

This document is the "LQP02 Printer Pocket Service Guide," a technical manual published in March 1982 by Digital Equipment Corporation. It provides comprehensive instructions for servicing the LQP02 daisy wheel printer and its optional accessories.

The guide covers the following key areas:

• Testing and Troubleshooting: Details self-test procedures (Logic, Printing, Loopback) and explains how to diagnose and resolve common printer malfunctions and "CHECK" conditions using extensive troubleshooting tables. It also includes steps for verifying power supply voltages.
• Field Replaceable Unit (FRU) Removal and Replacement: Provides step-by-step procedures for disassembling the printer and replacing various components, including printed circuit boards (SI controller, digital, analog, power supply, front panel), mechanical subassemblies, the motherboard, electronic subassembly, and the fan. A list of recommended spare parts is included.
• Cleaning and Lubrication: Focuses on the lubrication of felt wipers on the carriage guide shaft, noting when replacement is necessary.
• Options Servicing: Addresses the installation, removal, troubleshooting, and adjustments for the LQPX2-AC Automatic Sheet Feeder (ASF) and the LQPX2-AA Bidirectional Forms Tractor, including their respective troubleshooting tables and spare parts lists.
• Reference Information: Contains appendices detailing fuse locations, configuration switch settings (for self-test, baud rate, etc.), related documentation, and a physical/functional diagram of the printer.

The document is intended for service personnel, outlining the tools required for maintenance and emphasizing safety warnings, such as disconnecting power before FRU removal.