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. These high-speed, high-capacity communication networks are increasingly replacing copper cables, offering superior performance and. This guide offers practical steps to troubleshoot fiber optic cable issues, covering common problems, key tools, and preventive measures to ensure stable performance. The most common problems usually fall into four categories: Physical Layer: Transmission Performance: Equipment and Module Failures:. Good troubleshooting is a sequence, not a scattershot of tests.