General Industrial Troubleshooting — real-world interview & field troubleshooting questions with clear, practical answers. Tap any question to open its answer. Showing the first 70 questions free. The complete 150-question set is available as a PDF below. 1. Machine Start-up, Interlocks and General Faults Q1 The machine does not start when the Start button is pressed. How would you troubleshoot it? Answer Check incoming power, control voltage, emergency stop status, safety interlocks, overload relay and PLC permissives. Verify that the Start command reaches the control system; correct the failed interlock, wiring, fuse or device and then test the complete start sequence. Q2 The machine starts but stops immediately. What checks should you make? Answer Look for overload, low pressure, safety feedback loss, motor current rise, missing sensor confirmation or a PLC fault. Read the active alarm and sequence status before resetting, then remove the actual cause instead of repea...