Abstract: A printed circuit having a protective coating of lacquer or the like thereover is tested by bringing a plurality of resiliently mounted measuring pins into engagement with certain measuring points on the printed circuit. The printed circuit is then subjected to ultrasonic vibrations to cause the contacting pins to be impacted into good electrical contact with the measuring points on the printed circuit. The pins are resiliently mounted for axial movement in opposed openings in a pair of spaced plates and the plate and pin assembly is capable of being moved toward and away from the printed circuit.