My Master's thesis was about the ATLAS Diamond Beam Monitor (DBM). It is a telescope tracker made up of diamond and Silicon pixel detectors, designed for luminosity and beam background measurements. Unfortunately, shortly after initial commissioning in 2015, 11 of the 24 detector modules broke down. It was my task as Master student to recommission the DBM after some safety measures had been taken. The recommissioning, as well as investigating some of the reasons why the DBM lost so many models is documented in this thesis.