I talked about data recovery of deleted or corrupted files, but what if the hard disk itself isn’t even picking up on the computer? No amount of software can fix that. This can be a number of things.
The other day I fixed an external hard drive in this condition. The owner thought it was dead and that they had lost all their priceless files.
It turned out to only be a bad USB control board. Many external hard drives are actually just internal hard drives with a case and a little adapter going between the SATA connections and a USB connection. If this part fails, the hard drive won’t work at all – despite the actual hard drive inside the case still being fully functional. Usually this part is a fairly inexpensive (in this case it was $20) if you want to get the drive operational again. Otherwise, simply disassembling the drive and installing it internally into a PC using the SATA connections will work just fine to either just recover the files or make use of the drive for extra storage in your PC.
In other cases the control board on the drive itself could be bad. In this case you can usually source an identical control board and replace it. This is a safe repair as it’s not actually opening up the drive itself, and if successful would give you a working drive again.
Worse, the heads inside the drive could be bad. Usually this is caused by physical shock to the drive such as dropping it, although in older drives the heads do eventually fail. Assuming the plates are still good you can still recover the files, but you would have to disassemble the drive itself and transplant the plates to an identical drive. This is generally just for data recovery, ruins both drives, requires a special platter tool in hard drives that have more than one platter, and needs to be done inside a clean room (a room with no airborne dust) to have the best chance of success. This is one of those things that can run you $600+ at a specialist data recovery center, and that I have never personally attempted because I don’t have a platter tool or access to a clean room.
Worst case is the plates themselves are bad. This can be from a really bad drive failure, a lot of physical shock to the drive, or a failed attempt at transplanting the plates. In this case you’re out of luck and your data is lost.
In most cases listening to the drive can give you an idea of what might be wrong with it. I don’t charge anything just to take a look at it.