Abstract: A portable automatic test system which is deployable as separate modular elements in a plurality of separate protected transit cases, which after removal of the case covers, are stacked one upon the other to form the final test system. All electrical connections between adjacent modular elements are by zero insertion force connectors or low insertion force connectors positioned between the top and bottom of the adjacent elements. Moreover, the electronic components of each element are readily available through a file drawer design allowing ready access to individual printed circuits boards therein. The system controller also functions in a dual role, serving also as a portable maintenance aid.