Inverter Board Repair Course

Lesson 1 • What Inverter Boards Do

Covers DC-to-AC conversion principles and why inverter boards are used in electronics. Establishes the functional context needed for all subsequent repair work.

Lesson 2 • Inverter Board Topologies Overview

Introduces half-bridge, full-bridge, and push-pull topologies with their trade-offs. Students match topology to application before disassembling any hardware.

Lesson 3 • Reading Inverter Board Schematics

Teaches schematic symbol conventions and signal-flow tracing specific to inverter circuits. Accurate schematic reading reduces diagnostic time significantly.

Lesson 4 • Key Components and Their Roles

Identifies MOSFETs, IGBTs, gate drivers, transformers, capacitors, and inductors on a real board. Component recognition is prerequisite to fault isolation.

Lesson 1 • Power Supply and Load Testing

Explains bench power supply setup and dummy load use for safe board-level testing. Controlled conditions isolate faults without risking full-system damage.

Lesson 2 • Thermal Imaging and Component Inspection

Introduces thermal cameras and visual inspection methods to locate hot spots and physical damage. Early thermal detection prevents secondary failures during testing.

Lesson 3 • Analysing PWM Gate Drive Signals

Teaches how to capture and interpret gate drive waveforms to verify switching behaviour. Abnormal duty cycle or dead time reveals driver and control faults.

Lesson 4 • Multimeter Use for Inverter Circuits

Covers voltage, current, resistance, and diode-mode measurements on inverter boards. Proper probe technique prevents false readings and component damage.

Lesson 1 • Dynamic Testing Under Power

Guides safe power-up sequences and live signal tracing from input to output. Dynamic tests reveal faults invisible in static conditions.

Lesson 2 • Static Component Testing Procedures

Covers out-of-circuit and in-circuit testing of MOSFETs, diodes, capacitors, and resistors. Static tests confirm component integrity before applying power.

Lesson 3 • Failure Mode Classification

Categorises inverter faults as no-output, distorted output, overcurrent, overtemperature, and control failures. Classification directs the technician to the correct diagnostic branch.

Lesson 4 • Root Cause Analysis Techniques

Teaches five-why analysis and failure mode reasoning to identify underlying causes, not just symptoms. Root cause identification prevents repeat failures after repair.

Lesson 1 • Selecting Replacement Switching Devices

Teaches how to read datasheets and select equivalent or upgraded replacement MOSFETs and IGBTs. Incorrect substitution causes immediate or premature re-failure.

Lesson 2 • MOSFET Failure Modes

Explains gate-oxide breakdown, drain-source short, and open-circuit failures with their causes. Understanding failure modes guides both testing and replacement part selection.

Lesson 3 • Post-Repair Switching Device Verification

Validates replaced devices with static tests and live gate-drive waveform checks before full-load operation. Verification confirms correct installation and prevents re-failure.

Lesson 4 • IGBT Failure Modes and Testing

Covers IGBT-specific failures including latch-up, desaturation, and thermal runaway. IGBT faults often cascade, so early detection limits collateral damage.

Lesson 1 • Dead-Time and Shoot-Through Faults

Identifies incorrect dead-time settings and shoot-through conditions that destroy switching devices. Correct dead time prevents cross-conduction and catastrophic failure.

Lesson 2 • Replacing Gate Driver ICs

Guides IC removal, pad preparation, and installation of replacement gate driver ICs in SMD packages. Correct orientation and solder joint quality are critical for reliable operation.

Lesson 3 • Gate Resistor and Drive Strength Issues

Explains how gate resistor values affect switching speed, EMI, and device stress. Optimising gate resistance balances efficiency and reliability.

Lesson 4 • Gate Driver IC Architecture

Explains internal structure of high-side/low-side gate driver ICs, including level shifting and protection features. Architecture knowledge guides pin-level fault tracing.

Lesson 1 • Auxiliary Power Supply Diagnosis

Covers flyback and linear auxiliary supplies that power control circuits and gate drivers. Rail voltage errors cause cascading faults throughout the inverter board.

Lesson 2 • Film and Ceramic Capacitor Faults

Explains cracking, delamination, and dielectric breakdown in film and ceramic capacitors used in snubber and filter circuits. These faults often cause intermittent or high-frequency noise issues.

Lesson 3 • Inductor and Transformer Inspection

Covers winding resistance measurement, insulation testing, and core saturation detection for inductors and transformers. Winding faults cause output distortion and overheating.

Lesson 4 • Electrolytic Capacitor Failure and Replacement

Identifies bulging, leaking, and high-ESR electrolytic capacitors and explains their impact on ripple and stability. Capacitor replacement is among the most frequent inverter repairs.

Lesson 1 • PWM Controller IC Diagnosis

Covers oscillator, error amplifier, and output driver sections of PWM controller ICs. Controller faults produce incorrect duty cycle or complete loss of switching.

Lesson 2 • Overcurrent and Short-Circuit Protection

Diagnoses false triggering and non-triggering of overcurrent protection circuits. Correct protection behaviour prevents switching device destruction under fault conditions.

Lesson 3 • Microcontroller and Communication Faults

Addresses firmware-driven inverter boards with microcontroller clock, reset, and communication bus faults. Communication errors prevent remote monitoring and parameter adjustment.

Lesson 4 • Overtemperature and Overvoltage Protection

Tests thermistor-based temperature sensing and overvoltage clamp circuits for correct trip points. Faulty protection allows thermal and voltage stress to destroy the board.

Lesson 1 • PCB Trace and Via Repair

Covers conductive epoxy, wire jumper, and copper tape methods for restoring damaged traces and vias. Trace repair restores electrical continuity without full board replacement.

Lesson 2 • Full-System Functional Validation

Defines a structured test sequence from no-load to full-load that confirms all inverter functions are restored. Systematic validation catches residual faults before board return.

Lesson 3 • Quality Control and Return-to-Service Standards

Applies acceptance criteria, conformal coating, and final inspection before releasing a repaired board. Meeting defined standards ensures customer confidence and reduces callbacks.

Lesson 4 • BGA and Fine-Pitch Component Rework

Introduces BGA reballing, fine-pitch IC removal, and stencil-based solder paste application for advanced SMD rework. These skills address complex control IC failures on modern boards.