Repair of an Canon EF 24-105 lens back to projects

This canon lens could not focus anymore. The problem was in the electronic circuit board. Some water came in the lens and on the circuit board. The previous owner probably left the camera powered on so that the printed circuit board corroded. The lens was taken apart completely before discovering this small error. Anyway, some nice pictures of the inside are shown here.

The USM motor is clearly visible, a solid rind with carvings in it, and on top a piezo material which generates standing waves in the material. These standing waves move through the ring, and the 'feet' of the ring 'walk' over the stator surface. Great device with no moving components, and it must me much cheaper than a 'normal' motor drive (apart from the fact that the electronics are a little more complex)