Abstract: A wire harness including a plurality of wires surrounded by an outer tube wherein the outer surface thereof has an axial line drawn thereon. If the harness becomes twisted during handling and before installation, the line becomes helical and, since it is of contrasting color to that of the surface to which it is applied, it is readily visible to the installer. To correct the undesirable twisting, the wire harness is counter-rotated until the line becomes straight once again. The device can then be installed in the usual manner. If installation of a twisted wire harness is attempted, the additional distances which the branches must travel will make them too short to reach their intended connection points. A device for applying the line to the outer surface is also disclosed.

Abstract: A printed wiring board, on which an electronic parts are mounted and fixed by way soldering, is introduced into a heating furnace for heating at a temperature higher than or equal to a melting temperature of a solder. After sufficiently melting of solder, an impact force and/or a shearing force are applied. By this under a reduced connecting force, the electronic parts are removed from a printed wiring board. On the other hand, since the parts can be easily removed from the printed wiring board. Also, the parts and the printed circuit are separated for collecting useful substance and can improve resistance to enhance recycling efficiency.