EDIT: It turned out one HD was dead, the other didn't work because the SATA cable was broken. I replaced the SATA cable, and it works. My late 2011 MacBook Pro stopped responding yesterday when I woke it up from sleep after getting off the plane. It has two hard disks - one 120 GB SSD disk which Mavericks runs from and a normal 1TB hard disk mounted in the optical drive bay, containing my homedir and all my files. I powered it off, rebooted, and it would not recognize my SSD disk - however I have a Lion install on the 1TB disk which i use for development, so it booted off the other disk. The SSD disk did not show up in Disk Utility nor using diskutil from the command line. This led me to believe that the SSD disk had failed. "No big deal" I thought, "I will buy a new SSD disk when i get my paycheck". However, this morning, the computer would not boot at all. I booted it off a USB stick with DiskWarrior, which didn't detect any hard drives. So, I opened up the MacBook to see if there was something obviously wrong, and there was; the optical bay adapter had broken where it is screwed to the chassis, raising it about 4 mm, enough to push both SATA cables out of their sockets on the logic board. I reconnected both drives and started the computer, thinking it would work. Nothing. Still no drives recognized either from the boot options or from Disk Warrior. Also, the 1TB conventional hard drive makes a subtle noise for a few seconds when i power on the machine, sort of like a robot guinea pig (wuii, wuii, wuii, wuii, ...) Powering on with either drive disconnected also doesn't work. So, here are my questions: Can hotplugging the internal drives of a macbook damage either the drives or the SATA controller? Can the SATA cables break from a slight amount of twisting and turning caused by a loose drive? And can I buy replacements? My plan is to get hold of an external USB SATA enclosure and see if the drives are dead. Any other suggestions for diagnostics? I hope you can help!