If you've ever run into a problem with an external hard drive, you've probably tried to run a variety of checks against it and likely decided at some point that plugging it in internally would be easier to run some checks. SMART helps monitor drives and allows you to run some basic tests against them (when not mounted). So you can run SMART commands over USB! So before you go grab that screwdriver, give this site a read and try to run some checks against the drive over USB.
SMARTmontools over USB
