A carrier adapted to receive a plurality of printhead dies includes a substructure having a fluid manifold defined therein and a substrate mounted on the substructure, wherein the substrate is adapted to support the printhead dies. The substructure includes a fluid port communicating with the fluid manifold and at least one flush port communicating with the fluid manifold separate from the fluid port, and the substrate has a plurality of fluid passages defined therein with each of the fluid passages communicating with the fluid manifold.