There are normally 2 types of abnormal HDD sounds: “click” and “tick” sound. They all suggest the HDD has problems but these 2 sounds are caused differently.
Note that a healthy HDD will also have slight ticking sound when writing/reading. It is normal and this sound can only be distinguished in a very quiet environment. A bad head noise will be loud and the difference can be found easily.
* Clicking sound: bad head, cannot read SA and user data, the sound is from the head banging against limiter. Why?
1. HDD is too old.
2. HDD design flaw
3. HDD dropped
4. HDD flooded or burnt.
* Ticking sound: HDD is not on parking ramp but stuck on platter. After power on, platter is not spinning and HDD is giving ticking sound, sometimes accompanied by PCB beeping sound. Why?
1. Sudden power loss, head is not back to parking ramp.
2. HDD is awaken from Sleep status, platter is not reaching normal rotation speed but head is leaving parking ramp and stuck on platter.
* How to recover data from a clicking HDD?
A clicking HDD requires head change operation, the data recovery process is done in 4 steps：
1. Open HDD in a clean room/on a clean bench and change change. It will take more than 10 minutes to finish depending on technician skills and experience.
2. Check firmware and tweak. The HDD is manufactured firstly hardware assembly, then the program (firmware) matching and tweaking. After head change, technician will match firmware with hardware, this process can take minutes to hours depending on HDD brands.
3. Disk imaging. Technician will image the whole HDD after data is accessible. This is the most time consuming part of data recovery. It can take hours to days to finish depending on HDD conditions. A very bad conditioned HDD can take one month to image whole disk.
4. Data extraction and sorting. Extract the data from disk image, this can take several hours depending on data size.
The first step and second step are the key to reflect the technological gap between the data recovery companies. How engineers process them determines the success rate of data recovery. The third step can reflect the gap between the company’s data recovery hardware and equipment, which can decide the data recovery time.