What does it mean when a MacBook Polycarbonate Unibody (A1342) power LED blinks once and stays solid? The LED turns on normally; blinks ON, and then OFF, and then back ON again, and stays solid. There's nothing but a black screen. I tried looking up POST error codes for Intel Macs, but I guess Apple took the support page down, or there was a loading glitch on that page. Any help?