In a recent forum discussion that went on a tangent about the risks of running DIY data recovery programs without properly diagnosing a hard drive, one data recovery specialist had the understanding that if a drive detected and was able to read data, the heads must be working. Although the conclusion was wrong, his reasoning that because all the heads share one armature, they are co-dependent. In some cases, where the head pre-amp is the point of failure, this can be true. Depending on the brand or model of hard drive, some drives will do a quick head test and if they don’t all pass the test, the drive will spin down into a kernel mode.
Green – sectors read, Yellow – sectors that could not be read, White – sectors not yet read
The graphic above is a visual representation of the sectors cloned on a data recovery project, after the heads have been changed. The drive has 4 read/write heads, of which one is not reading at all. With the original heads, all heads had some read errors, with the fourth head not reading at all. After the head change, three heads read 99% while the fourth head still does not read. In this case, the drive fully detects and reads, but will show CRC errors when attempting to read any sectors associated with the fourth head.
It is our experience that before we get such drives in for lab recovery, the end user or their service technician try everything they can, including running data recovery and sector repair programs in hopes to get their data recovered. Not only are they unsuccessful, but they only cause further damage…especially with the sector repair programs, such as SpinRite and HDD Regenerator. It is for this reason that many projects arrive unrecoverable or end up being more complex and expensive data recovery projects.
So, what do we suggest? We suggest that if you have encountered a data loss situation, give us a call at 866-750-3169 and we can discuss your best course of action. The options will vary depending on the described condition of the drive, as well as the value of the data. In many cases, we will suggest that the damaged hard drive be sent to our lab for a free assessment and quote. If the cost to recover the data is too high or the project is deemed unrecoverable by our lab, you can seek a second opinion by another lab or proceed to try to recover the data on your own.