This sounds like one of two sanarios that could have happened:
1. The ribbon cable connecting the drive to the motherboard has been damaged.
2. When it was dropped the battery contacted it or another piece of metal in the device shorting it
I know the second one is a long shot but as phones and tablets don't have a hard disk it's not possible for a head crash.
I would say it's more likely that the cable connecting the drive to the motherboard is damaged as a result of catching on something or from shock