How do you identify the root cause of bearing failure from visual examination?

Fatigue spalling shows pitting on raceways, indicating normal end-of-life or overload. Abrasive wear shows polished surfaces from contamination - check sealing and filtration. Corrosion shows rust and etching from moisture ingress. Electrical erosion shows fluting or pitting from stray currents in motor bearings. Overheating shows discoloration (blue/brown) from lubrication failure or misalignment. Brinelling shows indentations from static overload or vibration during transport. Each pattern suggests specific corrective actions.