An optical scanner scans a first portion of a print of a body part such as a finger in a first area of an optical surface. A WTRU may set a transmit power for each of a plurality of channels mapped to multiple CCs. The lubricator is adapted to be remotely operable from a surface of the well to control fluid communication between the passageway located above the lubricator and a formation located beneath the lubricator. Over time, each chip in the stack becomes the spare chip.