Abstract: An automated electronics circuit test cassette assembly is provided for mating with a test platform. The platform comprises a platform common signal interface and a vacuum manifold having a combined registration and vacuum port coupler. The cassette assembly includes a cassette common signal interface providing electrical communication with the platform common signal interface and an alignment bushing providing combined registration and vacuum communication with the vacuum port coupler. A pattern of test probes mimic a test pattern on a printed circuit assembly (PCA), extending upwards from a probe support substrate and optionally downward from a clamshell probe substrate. The PCA is supported by a PCA support substrate floating above the test probe support substrate. The clamshell test substrate provides a vacuum seal above the PCA support substrate.