On Fri, 15 Jan 2016 06:48:18 +1100, "Rod Speed"
wrote:

So what clicks when the drive breaks?

That's mostly the drive moving the heads to a known spot to recalibrate
the position of the head arm.

You kids may not remember the Commodore disk drive that always banged
its head against the wall to learn its position. Users learned how to
bend things back into place after too many head bangings.

Oh, for the good old days !