Refurbished hard drive, a story...

Last month, we had received clients hard drive for recovery.
At the first point of view it was just another common Western Digital drive from the Dragon family WD30EZRX.
What was a little different compared to standard hard drives, was the label on the front of the drive, which made it easy to see that it was a "refurbished" hard drive. Refurbished hard drives have come to us before, but the situation was more specific this time.

This hard drive was carefully tested using a diagnostic tools, and after detailed analysis, we found that the problem of reading the data originated from defective heads.

By further visual inspection, our engineer noticed that one of the platters at the beginning of the outer edge, at a specific angle of light, gives a visually different outline due to the reflection of a light.  

 

 

Platters were placed on our platter stand 3.5" for more detailed examination.

 

 

 

This same pattern of a damage is followed by the second and third platters, in fact all in this series at the identical position have protrusions or damage.

We were not quiet clear how such damage could occur, practically on a perfectly flat, clean, polished surface showing a small protrusion (2mm).
The damage starts at the very edge of the boards, from the outside, but we cannot know how far this damage extends. This kind of damage to the boards according to our experience are not consequence of head damage..

 

 

The mystery remains. What caused the damage?

Is it a factory fault, a consequence of the impact, or perhaps a refurbished policy drive?

 

 

DATA RECOVERY PROCESS

 

Heads damaged, heads replaced, fingers crossed for luck.

 

 

 

The method we used to clone the disk is from the back to the inside.
From higher sectors to zero. We read the healthy sectors until we got to the first unreadable sections. And at this stage we had to skip sequentially as long as the wounded disk and tool allowed reading of the data.

At the end, we were able to get the file structure, tree, the MFT table was available.
As a final result we have recovered over 60% of usable files.
Impressive.