Tangled cords can make signals weak. Here are steps for safe handling: Keep connectors clean and dry. Untangle cables to. Fiber optic patch cords are often treated as low-risk consumables, yet a large percentage of optical link failures originate at the patch cord level. It also includes a list of common fault location items. Maintenance personnel can refer to this document for step-by-step troubleshooting when dealing with faults arising from the following. When it comes to testing fiber optic cables, a Visual Fault Locator (VFL) is an essential tool in your toolkit. It's a cost-effective and. Fiber optic troubleshooting is an essential skill for network administrators, technicians, and engineers responsible for maintaining and repairing fiber optic systems. What Makes Fiber Optic Technology.