Ten real diagnostic scenarios — bearing failures, misalignment, excessive vibration, pump cavitation, gearbox failures, seal leaks, fatigue cracking, thermal distortion, hydraulic and pneumatic faults — each worked from symptoms through measurement, diagnosis, and resolution.
Replacing a failed bearing and hoping the vibration doesn't come back is a technician's move, not an engineer's. This module is built around the opposite discipline: measure first, form a hypothesis consistent with the measurement, then test that hypothesis with a targeted change. It draws directly on the machine elements (Module 5), power transmission (Module 6), fluid mechanics (Module 7), and reliability (Module 13) material earlier in this program — troubleshooting is that same knowledge applied under pressure, against a real fault someone is waiting on.
Every scenario below was chosen because it has at least two plausible causes that look identical from the outside — a failed bearing that could be bad lubrication or misalignment, a leaking seal that could be a bad component or upstream cavitation — and each requires a specific measurement, not an assumption, to tell apart.