One of the most common calls we get is when someone has knocked their external hard drive off of their desk or counter. I have heard cats knocking the hard drives off, kids and users tripping over external hard drive cables. If an external hard drive falls 3 to 5 feet there is a good chance it might become damaged. This is for sure if it was running at the time.
When a hard drive has a physical shock, the heads can impact upon the platters and cause damage to the data. Sometimes the damage can be with the USB enclosure and not the hard drive. It is always a good idea to take your hard drive out of the case and slave it onto another machine to see if the BIOS can recognize it.
Call 727-345-9665 if you need help with your external hard drive. We also have software and tips for external hard drive repair here.