Industrial Electronics Repair — PLCs, Drives and Control Boards

Lesson 1 • Industrial Component Identification

Identifies contactors, relays, fuses, circuit breakers, and terminal blocks by function. Connects component roles to their position in a control circuit.

Lesson 2 • Electrical Safety in Industrial Settings

Covers lockout/tagout procedures, arc flash hazard categories, and PPE selection. Safe work habits established here apply throughout the entire course.

Lesson 3 • Electrical Fundamentals Review

Covers DC/AC theory, Ohm's law, and power calculations essential for panel work. Establishes the quantitative baseline every subsequent diagnostic task depends on.

Lesson 4 • Reading Industrial Schematics

Teaches ladder logic diagrams, wiring diagrams, and one-line drawings used in factories. Accurate schematic reading is the prerequisite for every repair task ahead.

Lesson 1 • PLC Power and Grounding

Details power supply sizing, redundancy options, and proper chassis grounding techniques. Poor grounding is a leading cause of intermittent PLC faults.

Lesson 2 • Specialty and Communication Modules

Introduces high-speed counter, motion, and network communication modules. Expands the technician's ability to service advanced PLC configurations.

Lesson 3 • PLC System Overview

Explains the CPU, memory, I/O bus, and power supply as an integrated system. Provides the mental model needed to isolate faults to a specific hardware zone.

Lesson 4 • Discrete I/O Modules

Covers sourcing vs. sinking wiring, voltage ratings, and LED status indicators on discrete modules. Correct wiring prevents module burnout and false diagnostics.

Lesson 1 • Timer and Counter Instructions

Explains TON, TOF, RTO timers and CTU, CTD counters with preset and accumulated values. Timers and counters appear in nearly every machine sequence program.

Lesson 2 • Program Monitoring and Online Editing

Teaches going online, forcing I/O, and making minor edits without stopping production. Safe online practices prevent unintended machine motion during diagnostics.

Lesson 3 • Ladder Logic Fundamentals

Covers XIC, XIO, OTE, OTL, and OTU instructions with real-world coil and contact examples. These instructions form the core of most factory PLC programs.

Lesson 4 • Data Handling and Math Instructions

Covers MOV, CMP, ADD, SUB, MUL, and DIV instructions used in setpoint and recipe management. Data instructions are critical for diagnosing incorrect process values.

Lesson 1 • Interpreting PLC Fault Codes

Decodes major and minor fault codes stored in the PLC fault log and maps them to hardware or software causes. Fault codes are the fastest entry point into any diagnosis.

Lesson 2 • I/O Module Fault Isolation

Uses LED indicators, forced outputs, and continuity tests to isolate faults to a specific I/O channel or module. Prevents unnecessary module replacement.

Lesson 3 • CPU and Memory Fault Recovery

Covers battery replacement, memory card backup, firmware updates, and CPU swap procedures. Protects program integrity during hardware replacement.

Lesson 4 • Systematic PLC Troubleshooting Workflow

Applies a structured five-step diagnostic process: observe, define, test, repair, verify. Consistent workflow reduces mean time to repair across all fault types.

Lesson 1 • VFD Power Stage Architecture

Details the rectifier, DC bus, and inverter sections including IGBT switching and PWM generation. Understanding power flow enables accurate fault localization within the drive.

Lesson 2 • VFD Installation and Commissioning

Covers enclosure sizing, input line reactors, output filters, and initial run verification. Correct installation practices extend drive service life and reduce EMI issues.

Lesson 3 • VFD Control Wiring

Covers analog speed reference, digital command inputs, relay outputs, and encoder feedback wiring. Correct control wiring is required before any parameter programming begins.

Lesson 4 • AC Motor and Drive Principles

Explains induction motor slip, torque-speed curves, and why variable frequency enables speed control. Motor behavior under VFD control differs from across-the-line starting.

Lesson 1 • Control Board Diagnosis

Diagnoses drive control boards by checking power supply rails, gate drive signals, and firmware integrity. Control board faults often produce erratic behavior rather than hard fault codes.

Lesson 2 • Drive Repair and Return-to-Service

Covers component replacement, parameter reload, and a structured return-to-service test sequence. Verified commissioning after repair prevents repeat failures.

Lesson 3 • Power Stage Component Testing

Tests rectifier diodes, DC bus capacitors, and IGBT modules using a multimeter and capacitor tester. Component-level testing avoids replacing entire drive assemblies unnecessarily.

Lesson 4 • Interpreting Drive Fault Codes

Maps common fault codes—overcurrent, overvoltage, undervoltage, overtemperature—to root causes. Fault history logs reveal patterns that single-event codes cannot.

Lesson 1 • Control Board Anatomy

Identifies power supply sections, microcontroller circuits, gate drivers, and signal conditioning on a typical industrial PCB. Board-level understanding guides efficient fault localization.

Lesson 2 • Passive Component Testing and Replacement

Tests resistors, capacitors, inductors, and diodes in-circuit and out-of-circuit using standard instruments. Passive component failure is the most common cause of board malfunction.

Lesson 3 • Functional Testing After Repair

Applies bench power supply testing, signal injection, and in-system verification to confirm repair quality. Functional testing before reinstallation prevents repeat downtime.

Lesson 4 • Soldering and Rework Techniques

Covers through-hole and SMD soldering, hot-air rework, and BGA reballing for industrial board repair. Proper rework technique prevents pad and trace damage during component replacement.

Lesson 1 • Data Logging and Trend Analysis

Uses PLC data logging, drive trend buffers, and SCADA historian data to identify recurring fault patterns. Trend data converts reactive repair into predictive maintenance.

Lesson 2 • Multi-Component Fault Analysis

Applies fault tree analysis and cause-and-effect diagrams to faults spanning PLC, drive, and field devices. System-level thinking prevents fixing symptoms while leaving root causes unresolved.

Lesson 3 • Industrial Network Diagnostics

Diagnoses EtherNet/IP, Profibus, and Modbus networks using protocol analyzers and built-in diagnostic tools. Network health directly affects PLC-to-drive communication reliability.

Lesson 4 • Servo Drive and Motion Control Basics

Introduces servo amplifier architecture, encoder feedback loops, and tuning parameters for motion axes. Servo systems are increasingly common in modern automated machinery.