Circuit Board Repair Course

Lesson 1 • Semiconductor Devices and Their Roles

Diodes, transistors, and MOSFETs as switching and amplifying elements on boards. Connects device physics to observable symptoms when components fail.

Lesson 2 • Reading and Interpreting Schematics

Schematic symbols, net labels, and signal flow conventions used in board documentation. Enables accurate fault tracing before touching any instrument.

Lesson 3 • Capacitors and Inductors on PCBs

Reactive component behaviour in AC and DC contexts, including filtering and energy storage. Directly explains decoupling, ripple, and timing faults.

Lesson 4 • Voltage, Current, and Resistance Basics

Ohm's Law and power relationships applied to real PCB traces and components. Builds the quantitative foundation for all diagnostic work ahead.

Lesson 1 • Specialised Diagnostic Instruments

LCR meters, logic analysers, and thermal cameras as advanced fault-finding aids. Each instrument targets fault classes unreachable by basic meters alone.

Lesson 2 • Oscilloscope Operation and Probing

Triggering, time-base, and probe compensation for capturing board signals accurately. Connects waveform interpretation directly to fault identification.

Lesson 3 • Soldering and Rework Station Setup

Temperature-controlled iron, hot-air station, and preheater configuration for reliable joints. Proper setup directly determines rework quality and component survival.

Lesson 4 • Power Supplies and Load Testing

Bench power supply setup, current limiting, and controlled board power-up sequences. Prevents secondary damage during initial fault investigation.

Lesson 1 • Integrated Circuit Functional Testing

Power-pin voltage checks, output logic states, and oscillator verification for common ICs. Narrows fault location to specific IC before committing to replacement.

Lesson 2 • In-Circuit Passive Component Testing

Resistance, capacitance, and ESR measurement with parallel circuit compensation techniques. Determines component condition without full board disassembly.

Lesson 3 • Passive Component Identification

Resistor colour codes, capacitor markings, and inductor value codes decoded from physical parts. Accurate identification prevents substitution errors during repair.

Lesson 4 • Transistor and Diode Out-of-Circuit Testing

Gain, leakage, and junction integrity tests using multimeter and component tester. Provides definitive pass/fail verdict before sourcing replacements.

Lesson 1 • Signal Injection and Tracing

Inject known signals and trace propagation to locate the stage where signal degrades or stops. Isolates faults to a single functional block rapidly.

Lesson 2 • Fault Classification and Symptom Analysis

Categorise faults as open, short, leakage, or parametric before measuring anything. Symptom-to-fault-class mapping accelerates the diagnostic path.

Lesson 3 • Visual Inspection Techniques

Systematic board inspection using magnification, lighting angles, and thermal cues. Visual faults found here eliminate unnecessary electrical measurement steps.

Lesson 4 • Divide-and-Conquer Isolation Strategy

Binary fault isolation by splitting the circuit into halves and testing each section. Reduces diagnostic steps logarithmically on complex multi-stage boards.

Lesson 1 • Linear Power Supply Fault Analysis

Transformer, rectifier, filter, and regulator stage faults in linear supplies. Each stage has distinct failure signatures that guide component-level diagnosis.

Lesson 2 • Post-Repair Verification and Load Testing

Full-load voltage regulation, ripple, and efficiency verification after PSU repair. Confirms the fix is complete and the supply meets original performance specs.

Lesson 3 • Switch-Mode Power Supply Fundamentals

Flyback, buck, and boost topology operation and their critical waveform signatures. Understanding topology determines which nodes to probe first.

Lesson 4 • SMPS Fault Diagnosis Procedures

No-output, low-output, and oscillating-output fault trees for switching supplies. Structured approach prevents repeated component replacement without root-cause fix.

Lesson 1 • Passive SMD Component Replacement

Removal and placement of 0402 through 2512 resistors, capacitors, and inductors by hand. Technique directly determines pad survival and joint reliability.

Lesson 2 • BGA Reballing and Rework

BGA removal, pad cleaning, reballing, and reflow with controlled thermal profiles. BGA rework is the highest-skill SMD operation and requires precise process control.

Lesson 3 • SMD Soldering Fundamentals

Solder alloy selection, flux types, and heat transfer principles for reliable SMD joints. Correct fundamentals prevent cold joints, tombstoning, and pad damage.

Lesson 4 • IC Package Removal and Replacement

SOIC, QFP, and QFN desoldering and soldering with hot air and iron techniques. Package-specific approaches prevent lifted pads and bridging on fine-pitch parts.

Lesson 1 • Memory Interface Fault Diagnosis

Flash, EEPROM, RAM, and NAND interface signal integrity and addressing faults. Memory faults produce erratic behaviour that mimics firmware or MCU failure.

Lesson 2 • GPIO, Interrupt, and Peripheral Faults

Stuck GPIO lines, missed interrupts, and peripheral clock enable faults on MCU boards. Logic analyser capture reveals timing violations invisible to a multimeter.

Lesson 3 • Serial Communication Bus Diagnosis

UART, SPI, I2C, and CAN bus waveform analysis and fault isolation with logic analyser. Bus faults are decoded from captured frames to identify the offending node.

Lesson 4 • Firmware and Boot Failure Diagnosis

Distinguishing hardware faults from firmware corruption using boot sequence signals. Prevents unnecessary hardware replacement when firmware is the root cause.

Lesson 1 • Repair Documentation and Traceability

Fault description, root cause, parts used, and test results recorded for every repair. Documentation enables warranty tracking and recurring fault analysis.

Lesson 2 • Burn-In and Thermal Stress Testing

Extended operation under elevated temperature and load to expose latent component faults. Burn-in catches marginal repairs before boards return to service.

Lesson 3 • Functional Testing After Repair

System-level functional test procedures that confirm the original fault is resolved. Tests must replicate the failure condition to validate the repair fully.

Lesson 4 • Root Cause Analysis and Failure Prevention

Systematic root cause identification to prevent recurrence of the same fault class. Transforms individual repairs into process improvements for the repair operation.