Audio Equipment Repair Course

Lesson 1 • Chemical and Thermal Hazard Management

This section addresses flux fumes, solvents, and soldering iron burns as routine workshop hazards. It establishes ventilation and first-aid protocols used throughout the course.

Lesson 2 • Electrostatic Discharge Prevention

This module teaches ESD risks specific to audio ICs, FETs, and digital components. It connects proper grounding habits to reduced component loss during repair.

Lesson 3 • Electrical Safety and Hazard Control

This section covers shock prevention, fuse protection, and safe handling of mains-connected equipment. It is mandatory knowledge before any live-circuit work in subsequent chapters.

Lesson 1 • Reading Audio Schematics

This module develops the ability to interpret schematic symbols and trace signal paths. It directly enables fault diagnosis in later chapters.

Lesson 2 • Core Electrical Concepts for Audio

This section covers voltage, current, resistance, and power as they apply to audio circuits. It establishes the quantitative language used throughout the course.

Lesson 3 • Passive Components Identification

This module teaches recognition and function of resistors, capacitors, and inductors in audio gear. It connects component behaviour to audible symptoms when they fail.

Lesson 4 • Active Components in Audio Circuits

This module introduces transistors, diodes, and integrated circuits as signal-processing elements. It prepares learners to trace signal flow through amplification stages.

Lesson 1 • Power Amplifiers and Speaker Systems

This module analyses Class A, AB, D, and H amplifier topologies and their loudspeaker interfaces. It prepares learners to diagnose output-stage failures safely.

Lesson 2 • Signal Processors and Effects Units

This module surveys compressors, equalizers, reverb units, and delay lines as discrete repair targets. Students identify the functional blocks inside each processor type.

Lesson 3 • Microphones and Preamplifiers

This module examines dynamic, condenser, and ribbon mic designs alongside their matching preamp stages. It establishes how transducer type dictates circuit requirements.

Lesson 4 • Mixing Consoles and Signal Routing

This module covers channel strip architecture, bus routing, and summing amplifiers in analog consoles. It connects circuit topology knowledge to systematic fault isolation.

Lesson 1 • Surface-Mount Component Soldering

This module introduces hot-air rework, fine-pitch IC soldering, and paste application for SMD work. It extends repair capability to modern compact audio hardware.

Lesson 2 • Soldering Iron Selection and Care

This module covers tip types, temperature control, and station maintenance for consistent joint quality. Proper iron care directly extends tip life and joint reliability.

Lesson 3 • PCB Repair and Trace Restoration

This module teaches lifted pad repair, trace bridging, and via restoration on damaged audio boards. It enables recovery of boards that would otherwise be scrapped.

Lesson 4 • Desoldering Methods and Tools

This module covers solder wick, vacuum pumps, and hot-air removal for safe component extraction. It prevents pad and trace damage that would complicate subsequent repairs.

Lesson 1 • DC Voltage and Bias Measurements

This module teaches systematic voltage mapping against schematic values to locate biasing faults. It connects out-of-spec voltages to specific failed components.

Lesson 2 • Diagnostic Methodology Overview

This module establishes a repeatable fault-finding process: symptom analysis, hypothesis formation, and verification. It prevents random part replacement and reduces repair time.

Lesson 3 • Intermittent and Noise Fault Isolation

This module addresses the hardest fault class: intermittent failures and noise artifacts caused by cold joints or aging components. It teaches thermal and mechanical stress testing.

Lesson 4 • Signal Tracing Techniques

This module uses oscilloscope and audio probe to follow signal through stages until loss or distortion is found. It directly locates the faulty stage in multi-block devices.

Lesson 1 • Linear Power Supply Operation

This module explains transformer, rectifier, filter, and regulator stages in linear supplies. It provides the circuit model used for all linear supply fault diagnosis.

Lesson 2 • Diagnosing Power Supply Faults

This module applies voltage mapping and ripple measurement to locate failed rectifiers, capacitors, and regulators. It connects supply faults to downstream audio symptoms.

Lesson 3 • Switching Power Supply Fundamentals

This module covers flyback, forward, and half-bridge SMPS topologies common in powered speakers and interfaces. It prepares learners for high-frequency fault diagnosis.

Lesson 4 • Capacitor Replacement and Reforming

This module teaches correct electrolytic capacitor selection, polarity, and voltage rating for supply rebuilds. It includes reforming procedures for long-stored equipment.

Lesson 1 • Output Stage Replacement Procedures

This module guides safe removal and installation of output transistors, including thermal interface preparation. Incorrect procedure causes immediate re-failure of new devices.

Lesson 2 • Performance Verification and Burn-In

This module uses THD measurement, frequency response sweep, and extended load testing to confirm repair quality. It catches latent failures before equipment is returned to service.

Lesson 3 • Preamplifier and Input Stage Faults

This module diagnoses noise, DC offset, and gain errors in input and preamp stages using signal tracing. It builds on voltage measurement skills from the diagnostic chapter.

Lesson 4 • Bias Adjustment and Quiescent Current

This module teaches idle current measurement and trimmer adjustment to minimise crossover distortion and heat. Correct bias is the single most critical amplifier alignment step.

Lesson 1 • Network Audio and Control Bus Faults

This module addresses faults in Ethernet-based audio transport, MIDI, and RS-485 control buses. It enables repair of stage boxes, digital snakes, and remote-controlled devices.

Lesson 2 • Clock and Synchronization Repair

This module diagnoses crystal oscillator, PLL, and word clock distribution faults causing jitter or sync loss. Clock integrity underlies all digital audio performance.

Lesson 3 • Digital Audio Fault Characteristics

This module identifies the unique symptoms of digital faults: dropouts, clicks, bit errors, and silence. It distinguishes digital failures from analog ones before opening the device.

Lesson 4 • Hybrid Device Integration Testing

This module validates repaired hybrid devices by testing analog and digital domains together under real-world signal conditions. It confirms end-to-end performance before sign-off.