Check Fiber Cables : Look for visible damage, sharp bends, or loose connectors. Clean Connectors : Use lint-free wipes and isopropyl alcohol to remove dust or oil. This document presents a troubleshooting guide for fiber optic cables once deployed and in regular use. It also includes a list of common fault location items. This saves time and prevents needless part swaps. Symptom: intermittent errors, high insertion loss, or a noisy link. Fiber optic troubleshooting is an essential skill for network administrators, technicians, and engineers responsible for maintaining and repairing fiber optic systems.