The invention relates to a method for positioning electrodes in an electrode array comprising a plurality of electrodes for central nervous system monitoring from the forehead of a subject. The crushing hammer comprises at least two alternative fastening elements with which it can be fastened to a boom of a work machine. A bank layer separates a pixel in the group of the plural pseudo-pixels from a pixel in the group of pixels in the effective display region, and shields light leaked from a space between pixels located adjacently each other within the effective display region. A quick change adapter having a female drive can be connected to the male square drive such that the tool handle can be used with a wide variety of tools including taps and extractors, sockets, screwdriver bits and the like. One or more of the field replaceable units connect to the system through a midplane, located within the subchassis.