This is a very common problem, and is often a symptom of bad sectors and/or a failing drive.
Sometimes drives with these symptoms aren’t too bad, but other times the damage causing the symptom can be severe.
The drive or computer has been in a fire or subjected to smoke and/or heat-damage from a fire.
We’ve recovered data from hundreds of deleted or formatted drives over the years!
It’s quite common for us to see external hard drives and flash drives that have damaged USB ports.
After the installation of hardware, software, or both, your system isn’t running correctly, and you are not able to access your important files.
A liquid spill or submersion in liquid has rendered your hard drive or SSD inoperable.
You can’t find a file or group of files that you know should be on the hard drive.
Your drive has suffered some kind of electrical damage (power surge, blackout, lightning, etc.)
The drive or computer was dropped, knocked down, tipped over, punched, thrown, smashed, or had something fall on it.