This problem first appeared mid 2011 and we started seeing a number of drives that were slow to initialise and again when attempts were made to read data the drive would either be incredibly slow or would hang the computer, on computers where affected drives were the main drive, the computer would not even start. Many people and other DR companies were misinterpreting this problem as weak heads or failed media.
We started our research by buying a number of faulty hard disks and closely examining the modules in the factory or firmware zone of the hard disk. We found that in drives with this problem one of the firmware modules contained a lot more data than on good working drives.
We set about examining this problem more closely and found that resetting the module to default values full access to the data was achieved and the drive was basically repaired but still with some bad sectors. Deeper analysis also reveals that the problem arises when one or more surfaces develop bad sectors and they get added to a Pending or Reallocation list. By examining the logs we can also determine which heads are likely to give problems when reading and so we are able to read the good surfaces first and return to the bad surface once the good ones are copied.
You can contact us for data recovery of your Western Digital hard disk or view more information about our hard disk recovery services.
The problems occur on all drives from desktop, laptop and all sizes of external hard disk. It also affects the Western Digital NAS series (red) drives. We have seen the problems on drives from 160 GB up to 4 TB ranges.