A mounting arrangement for a telecommunications system, the system including a panel and a frame. A projection and a corresponding opening are respectively formed on opposing bordering surfaces of the cutting line between the first and second bearing cage sections, and are configured to fix the bordering surfaces to each other in three directions upon meshing of the projection with the opening. When two types of connector bores are formed, a color indicator may be engaged with a feature of the core portion that is located in proximity to a connector bore of the first type, and then the overlay portion is formed over the indicator. A feedback corrective process is performed on a second set of semiconductor wafers based upon the lifetime tracking trench features. A phase difference between the read clock signal and the write clock signal is detected when writing data blocks to the storage medium in a seamless formation. The memory divides the operational state of the drive unit into plural stages by using the operation amount and the revolution speed as parameters.