What kind of damage to the telephoto lens can't be repaired?

it is irreparable that the lens is completely broken and the lens has a lot of corrosion. A good telephoto lens can't be repaired in the following situations: the lens of the lens is completely broken, the lens is corroded a lot, the shell is deformed, and the circuit fault occurs inside the lens. A long focal length lens refers to a photographic lens that is longer than the focal length of a standard lens. Long focal length lenses are divided into ordinary telephoto lenses and ultra telephoto lenses.