I would send it for checking... It reminds me of a weird problem I've had with my D3x.
A "fried" electronic of a lens fried the camera's AF module. Observable result were random moving of the focusing ramp of the lens (then any others), without acquisition of a target, and/or no focusing at all (still lens).
The AF module was changed three times before Nikon could find the origin of the problem, my 35/2AFD, as twice we tested the repair with this precise lens. Once repaired, the lens is in perfect working order, the camera too...
The camera was under warranty, but the lens was charged for a replacement of the whole electronics... Happily , and because I live in the capital where we have a Nikon "shop" it took less then a week's time for the whole thing !