This typical hard drive clicking noise means that the System Area (SA) cannot be read. It could be simple or complex to fix.
The System Area is located on the magnetic platters of your hard drive. It is typically on the outside cylinder for a 3.5? hard drive and on the inside cylinder for a 2.5?. This is a very complex area. It is knows as well as Maintenance track, Negative cylinder, Reserved cylinder, Calibration or Initilization area or even Disk ware.
The reason of hard drive making clicking noise because we know the SA cannot be read. You can have 4 main reasons (and a possible combination of them) for this to happen:
Heads are dead
Preamplificator is dead
SA corrupted or scratched
Firmware on the PCB
Whatever you do, you will need to repair the hard drive first.
For heads and preamplificator…well you only have a choice which is to swap the head of your drive. This is where it gets expensive in terms of data recovery services. Head swapping should be done in a white room, but if you are skilled enough you can try it in a clean environnement if you don't plan to spend money anyway on your data. Head issue is very common if you dropped your external
hard drive.
If the SA is scratched you might have a shot through a live pcb swap. It will basically bypass the reading of the SA and you have a cheap shot at getting your data back.
It all depends on what data you need to recover. If it's critical data then I would recommend Gilware.com for data recovery.