Industrial Fault Library
Practical troubleshooting for common automation faults — symptom, root cause, diagnosis and fix, with the equipment and spare parts that solve them.
Encoder Faults: Signal Loss, Position Drift and Count Errors
Random position drift is usually not the encoder: coupling slip, shield grounding and cable routing first, scope the differential pairs last.
Troubleshoot →Vacuum Pump Not Reaching Vacuum: Leaks, Oil, Valves and Wear
First isolate: is it the pump or the system? The blank-off test, then oil, gas ballast, vanes and exhaust valve in order.
Troubleshoot →Checkweigher Drifting or Inaccurate: Mechanical, Environmental and Timing Causes
False rejects climbing or zero drifting between shifts - the systematic check order: mechanics, environment, timing, then the load cell.
Troubleshoot →Industrial Robot Collision Alarm: Safe Recovery and Root-Cause Prevention
The safe jog-out sequence after a collision stop, when re-mastering is required, and the three settings that prevent the next crash.
Troubleshoot →VFFS Bagger Weak or Leaking Seals: Temperature, Pressure, Time and Film
Leaking bags rarely have one cause. A four-factor method - temperature, pressure, dwell, film - plus the product-in-seal problem everyone ignores.
Troubleshoot →Hydraulic Pump Noise and Pressure Loss: Diagnosis and Fix
Whining, rattling or falling pressure - how to tell cavitation from aeration from wear, and fix each one.
Troubleshoot →Coding & Marking Print Quality Problems: TTO, CIJ and Laser Diagnostics
Faded, smeared, missing or unreadable codes fail scans and fail audits. A diagnostic by printing technology — thermal transfer, continuous inkjet and laser — with the settings and consumables that actually control quality.
Troubleshoot →Gearbox Noise and Vibration: What the Sound Is Telling You
A gearbox that whines, growls, knocks or hums each has a different likely cause. How to read the noise, what vibration analysis adds, and when noise means 'monitor' versus 'stop now'.
Troubleshoot →Induction Sealer Not Sealing or Weak Seals: Troubleshooting Cap Liners
No seal, partial seal or burnt foil on an induction sealer is usually liner, power-to-speed, or head-height — rarely the sealer itself. A quick diagnostic by symptom.
Troubleshoot →Motor Losing Steps or Position Error: Diagnosing Stepper and Servo Drift
A axis that gradually drifts out of position or a stepper that loses steps is usually torque margin, acceleration, or resonance — not a dead motor. How to tell mechanical from electrical from tuning.
Troubleshoot →Labels Wrinkling, Flagging or Bubbling: Applicator Troubleshooting
Cosmetic label defects come from a mismatch between label material, adhesive, surface energy and application geometry. A defect-to-cause map that fixes it without endless trial and error.
Troubleshoot →Conveyor Belt Mistracking (Running Off to One Side): Causes and Correction
A belt that drifts sideways causes edge wear, spillage and jams. Mistracking is a geometry and tension problem — chasing it with belt replacements wastes money. The systematic correction order.
Troubleshoot →Machine Vision False Reject Rate Too High: Causes and How to Reduce It
A vision system rejecting good parts is usually a lighting-stability, threshold, or handling-variation problem — not the algorithm. A structured way to cut false rejects without missing real defects.
Troubleshoot →Pneumatic Cylinder Slow, Weak or Jerky: Diagnosis and Fixes
A cylinder that lost speed or force is usually leaking air, starved of flow, or suffering seal/lubrication wear. How to isolate supply, valve, cylinder and load in minutes.
Troubleshoot →PLC Communication Loss (Profinet/EtherCAT/Modbus): Systematic Troubleshooting
Intermittent fieldbus dropouts are usually physical layer, addressing, or noise — rarely the CPU. A layer-by-layer method that finds the fault fast instead of swapping cards blindly.
Troubleshoot →Servo Motor Overheating / Overload Alarm: Why It Happens and How to Solve It
A servo overheating or throwing an overload (OL) alarm is a duty-cycle, tuning, or mechanical problem far more often than a failed motor. How to read the real cause from current and cycle data.
Troubleshoot →Photoelectric Sensor False Triggering or Missed Detection: Root Causes and Fixes
Intermittent sensing on a production line is usually ambient light, reflectivity, or alignment — not a dead sensor. A diagnostic checklist for diffuse, retroreflective and through-beam types.
Troubleshoot →VFD Overcurrent (OC) Fault: Causes, Diagnosis and How to Fix
A VFD tripping on overcurrent (OC/OC1/OC2/OC3) usually points to acceleration, short-circuit, or load problems. Step-by-step diagnosis by when the fault occurs, plus the parameters to check.
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