Because of electronic assemblies’ miniaturization, new issues can arise. That is the case of small metal particles that are not visible with the naked eye and can cause malfunctioning in the electronics assemblies. In this study, several assemblies were analyzed to determine the material that was causing short among component leads; for that, visual microscopy, metallographic microscopy, SEM/EDX, XRF, and FTIR were used. The materials then were compared with others coming from the production line and raw materials, and not only their origins but also their contamination vectors were determined. The results were useful to determine the probability of causing any malfunctions according to the type of particle. Several recommendations were given and the implementation of a vacuum system to remove the metal particle from key areas of the assembly was implemented. The reduction of incidences was reduced as consequence of the recommendations.