|Sometimes when a FiberInspector Pro is plugged into a fiber, the core of the fiber images is covered in a white light.
You may have plugged in your FiberInspector Pro into a live fiber. The FiberInspector Pro has a safety filter that blocks harmful light being emitted from an energized fiber. When you see the light, it is coming from an 850 nm source. Higher wavelength sources will not be displayed on the FiberInspector Pro. When you see this light and wish to inspect the fiber, you will have to disconnect the fiber from the source on the other end and continue.