How it works
A mechanical disk makes some normal movement sounds, so an isolated click does not prove failure. Repeated new tapping, failed detection or unreadable files is more concerning, particularly when behaviour changes from the drive's usual pattern. Bad sectors describe areas that cannot be read or written reliably. Increasing error counts or repeated read retries add useful evidence, but sound and health counters do not identify the same problem in every model.
A disk struggling to read can become slower because it retries operations. Repeated full scans, benchmarks or repair attempts may consume the remaining opportunity to retrieve important files. An external disk can also behave abnormally with inadequate power or a poor connection. That possibility should be checked appropriately, without assuming that changing a cable will repair damaged mechanical components. Never open the sealed drive to inspect the heads.
Practical checks
Stop unnecessary writes and decide how valuable the unbacked data is before further testing. If access remains stable, preserve important readable files using an appropriate plan. For irreplaceable data or obvious mechanical distress, seek specialist recovery guidance instead of repeatedly restarting the disk. Record the model, symptoms and any existing diagnostic codes. Replacing a failing drive solves the hardware risk, but restoring data still requires a usable backup or successful recovery.