A pallet truck has a power unit including a main casing for housing drive apparatus and a platform onto which an operator may step and ride while controlling the truck. The closed subsystem typically includes multiple parts that ensure that content protection keys and protected content are never revealed outside the closed subsystem. Imagery collected from calibration beads can be used to determine core size and stability and TDIflow speed synchronization. A resistor is formed in the second interlayer insulation layer in the second region of the substrate. The connecting sections are cut off, and the carrier strip is removed.