First you have to locate the damaged location of the fiber optics cable. This can be done either by using a Visual Fault Locator (VFL) or an Optical Time Domain Reflectometer (OTDR).
Based on the location of the fiber cable damage as indicated either or both VFL and OTDR you can decide on a what type of repair required.
The repair might required a fusion splicing between cables, a pigtail assembly, replacement of faulty adapters, macrobending in splicing tray or faulty patchcord due to rodents.
I have been in the field of fiber optics since early 1990s. I gained fiber optics skills and knowledge via my working experience as end-user, main contractor and sub-contractor and finally as an optical fiber enterpreneur.