Not possible to know without opening it physically and doing a thorough inspection. But I suspect the culprit to be the lens motor or the gear coupling for that motor. Usually some foreign object might got in there, or a piece was diffracted and only recently showed up as an issue.
I don't believe anyone "repairs", in the sense of fixing a part and reusing it. But It can definitely be replaced, and with a bit of internal cleanup the camera should be as good as new.
But until then, I recommend you do not operate it to avoid exacerbating the problem or creating new ones.
