geoffclements :
USAFRet :
And where did this 18 volts come from?
Most probably, just the external enclosure is fried.
But you won't know until you take it apart and try just the drive on its own, as an internal drive.
The 18 volts came from the power supply to a laptop that was connected to the drive by mistake!
OK...
And you've verified that this does not work when plugged in with the right power supply?
As said, it is likely the enclosure is fried.
Have you taken the drive out, and see if it works as an internal drive?