A visual fault identifier or visual fault locator (VFI / VFL) is a visible red laser designed to inject visible light energy into a fiber. Sharp bends, breaks, faulty connectors and other faults will “leak” red light allowing technicians to visually spot the defects. However, like any piece of technology, these cables can sometimes experience issues that can hinder their performance or render them entirely useless. An optical cable going bad might show symptoms like sound distortions, loose connections, visible damages, and the absence of a red indicator light. Mishandling, such as improper plugging, poor storage, and dirty connectors, can damage optical cables.
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