Abstract: The test device is an electrolytic apparatus for the simultaneous non-destructive testing of the integrity of pluralities of circuit boards for continuity and anti-continuity or short circuits, including such circuit boards as employ multi-layer or multi-level interconnection wiring, whether it be printed wiring or screen printed or thermally deposited circuits. Transient electro-deposition of one ion from an alkali halide water solution temporarily modifies the optical reflectivity of exposed circuit terminals or metal parts of the circuit boards under test in a characteristic and easily recognized manner according to the continuity status of the associated circuit paths.