Editor’s note: The bad sector is a very common problem for hard disk drives. All hard drives tend to develop a different amount of bad sectors during their lifetime. The bad sector gives people big headaches both in daily lives and forensic investigations. What’s more, when the bad sectors become more and more, sometimes they may affect the working condition of the head, results that the head gets stuck on the sectors, or even make the head damaged. Today, our forensic experts will introduce a real case solved for our customer by SalvationDATA.

What are the bad sectors?

A sector is the basic data storage unit on a hard drive. When a sector fails to respond to read/write requests, it will be marked as a bad sector by the drive firmware or the OS. There are two types of bad sectors, hard bad sectors are caused by physical damages while soft bad sectors are caused by logical corruptions.

No matter it is a hard or soft bad sector, once a bad sector is detected, the hard drive will redirect the logical address to another spare physical sector. So the file that originally included the bad sector will become corrupted. In the worst situation, after a hard drive has developed so many bad sectors, the entire hard drive may become inaccessible. And the valuable digital data on the drive will be lost to us.

Now let’s see the real case about too many sectors result in the damaged head, under this situation, our forensic experts help to get the data back.

Background: our customer feedback to us about his damaged hard disk, which cannot be recognized by the computer, but many important data stored in the disk, so he asks help for us and entrusts the damaged disk. Also, In this article, we would like to introduce the patented technology integrated into our computer forensic product DRS (Data Recovery System).

Step 1:

After received his damaged disk, the first thing that comes to our mind is that make a pre-diagnostic for the disk, after connecting the disk with our DRS, it shows the screenshot below:


Step 2:

Then after check the disk running noise, our forensic experts conclude that the disk head may have been stuck, under this situation, we have to open the hard disk to check the internal condition. After that we take the hard disk to Clean Room and try to open the disk, as expected, the head does not return to the seat, result that the disk cannot be read.


Step 3:

We put the disk dead to return to seat by professional tool, then try to make a full image for the disk by expert mode in DRS, hope it can be working, However, when we make image until about 100GB data (totally 750GB), the head get stuck again, we explain to the customer that the head may have some problem and advise to replace the head to try again, after get the agreement from customer, we start to replace the new head.

Image 1

Step 4:

After successfully replace the head, we once again make a full image by expert mode in DRS. Equipped with a new head, the disk seems to work well and the process of the image is smoothly going.

Image 2


Finally, we get back the customer required data, and make a clone of the original target disk, perfectly solved the customer problem. If you are interested in our products, Come and check out our website for more information. You can also go to our resource page to download our forensic products for free. We welcome you to contact us and claim your free product trial!