A self-test electronic assembly performs self-testing, such as diagnostic or run-in testing of components and circuits, based upon internally stored test procedures. The results of self-testing are stored internally to the device, providing valuable information regarding the self-test electronic assembly, both during the manufacturing process, and preferably for ongoing in-situ operation. A test system is preferably linked to one or more self-test electronic assemblies, and provides loopback circuitry for each installed self-test electronic assembly, whereby the self-test electronic assemblies can further test components, circuitry, and security encoding and decoding operation. The preferred test rack also provides efficient and consistent monitoring and quality control over the self-testing of self-test electronic assemblies. During in-situ operation, the self-test electronic assemblies preferably monitor operating parameters, and continue to periodically perform self-testing, while storing the information within the device, and preferably transmitting the information to an external location.