A precision alignment system for the alignment of modular frames of an electronic sign including a plurality of precision alignment mechanisms which are mounted to the outer panels of the modular frames and an alignment fixture having a plurality of configurable jig towers. The configurable jig towers include moveable components which are used to precisionally align the outer contact surfaces of contact blocks in the precision alignment mechanisms for subsequent intimate contact between other like outer contact surfaces of contact blocks in the precision alignment mechanisms of horizontally and vertically adjacent modular frames.