[ Wade Dunham wrote: . . . but he reports that after a couple of minutes, it shuts down & restarts intermittently. Prior to shipping, it stayed on 24/7. ] It's possible that , during shipping, the DC-to-DC Board may have dislodged slightly from its connector. Correcting the problem entails removing the core from the acrylic enclosure and reseating the DC-to-DC board. There is an Apple manual, document 073-0545, which details how to get to this power component inside your core. D-B