If you have this drive and are having trouble detecting it, you may find our step by step troubleshooting guide for WD drives helpful.

This drive arrived at our offices but was not showing up in finder or on a PC. It did however show in disk Utility, but it would not mount.

Once we opened this drive, we found that it contained a WD20NMVW-11AV3S4, which had a USB bridge directly on the Printed Circuit Board.

We were able to attach the drive to our system, and read the firware from the drive. There was only 1 Service Area defect that had been reassigned, but that would indicate that this drive was starting to have issues with the firmware.

These drives contain 8 Read/Write Heads, and all of them seemed to pass the tests that we carried out on them, so the hardware issue was within the firmware itself, or on the platters of the drive (bad sectors), not the heads.

Once we ascertained the issue with the firmware, it was temporarily repaired and the data was recovered by ensuring that the drive bypassed the computer and connected directly to our system so that the drive was not trying to read the Master File Table all at once which can cause this issue.

Bad sectors were found on the platters of the drive in the Master File Table which would explain the issue that this Western Digital hard drive had with being recognized. Along with the fixes we made to the firmware enabled us to access the data.

The drive was encrypted using FileVault which was decrypted by using the password supplied by the client.

Around 95% of the requested data was recovered from the drive. Client was very happy.