The invention relates to testing apparatus, such as the type known as a burn-in test socket for integrated circuit "chips", where the chips are essentially planar electronic devices having a plurality of chip leads or traces, laterally projecting therefrom, for electrical interconnection to complementary traces on a planar electronic device, such as a mother board, upon which the socket may be mounted, during testing. The socket comprises a frame member for mounting to the planar electronic device, where the frame member includes electrical means for engaging chip leads and applying electrical current thereto during testing. A second element of the socket is a two-piece, adjustable cover member consisting of first and second members floatably mounted together by plural compression springs, where the first and second members are axially movable relative to one another. Specifically, the first member includes a force generating surface to apply a uniform force on the chip leads in contact with said complementary traces, while the second member, overlying the first member, includes at least a pair of latching members adapted to secure the cover member to the frame member during chip testing.