As we discussed above, remove dirt, dust and oil from fingerprints with pen-style cleaners or alcohol wipes. Identify cable damage using a VFL tester. Identifying and resolving issues in fiber optic. Fiber optic networks are celebrated for their speed and reliability, but even the best systems can encounter problems. This guide will walk you through diagnosing and resolving common. Connector-related problems are one of the most common issues in terminal boxes. Loose connectors, misalignment, and dirty connectors can result in signal loss, increased reflectance, and degraded performance. Power. Problems within a fiber link can occur due to a wide variety of reasons. Or it could be caused by the quality of the connector itself, such as poor end-face geometry that doesn't pass the. Dust caps can't help an already compromised connection. They're easy to use — simply.