An apparatus and method for multi-point detection in a power source equipment (PSE) device is provided. During multi-point detection, a series of at least four currents is sequentially applied to a link port of the PSE device. Each current is applied during a different measurement interval. A voltage measurement sample is obtained for each of the measurement intervals. A difference in voltage between alternating voltage samples is determined and used by a detection module to determine whether a valid power device is coupled to the link port of the PSE.