Lexicon 224X Service Manual

Details performance and technical specifications of the Lexicon 224X.

General overview of the manual and product features.

Safety warnings and procedures for handling electronic components.

Covers connectivity, serviceability, environment, size, and weight.

Instructions for routine cleaning and filter replacement of the unit.

Procedures and required information for sending the unit for repair.

Details on how to obtain replacement modules quickly.

Contact information and procedure for ordering replacement parts.

Explains the terms, conditions, and limitations of the product warranty.

High-level description of the 11 major functional modules and signal flow.

Details the control interface, switches, slide pots, and display functions.

Explains the function and components of the SBC module and its microprocessor.

Describes the memory expansion module with battery-backed RAM and ROM.

Covers clock generation, state generation, and control signal circuitry.

Details the data memory, address generation, and communication over the DAB.

Explains the ARU's register file, multiplier, accumulator, and overflow handling.

Describes the FPC as an interface between DSP and analog I/O.

Details the gain conditioning, filtering, and digitization of audio signals.

Explains the DAC, gain ranger, and filtering for audio output channels.

Details the six regulated DC voltages and one unregulated AC voltage produced.

Lists the necessary equipment for performing tests and calibration.

Procedures for testing the overall functionality of the system.

Tests related to the unit's internal power supply voltages.

Tests for input sensitivity, output sensitivity, and frequency response.

Steps for calibrating various parameters like offset and phase-lock loop.