The drive was frozen, making a faint, repetitive clicking sound. I tried to power it down but the power button did nothing, no matter how long I held it down. I unplugged the drive and plugged it back in and now I can’t connect to the drive on any of my devices–Mac OS Powerbook or the Xbox 360.
Tried swapping cables, using different ethernet ports on my router, and unplugged and plugged it back in several times. No idea what to do next other than go to a data recovery service. Any new ideas would be greatly appreciated.