A method and apparatus are provided for implementing very high density signal probing of a printed circuit board having a pad pattern connected to signals of interest. A metal plate includes a plurality of through holes arranged in a predefined pattern that corresponds to the pad pattern on the printed circuit board. At least one signal module is inserted within a selected one of the through holes of the metal plate. Each signal module defines a coaxial connector for electrical mating engagement with a coaxial cable connector and has an embedded resistor. At least one power/ground module is inserted within a selected one of the through holes. Each power/ground module contains a high dielectric constant material between an outer conductor and a center conductor defining a capacitor. The capacitor provides a low impedance path between the metal plate and a power or ground pad of the printed circuit board.