If you have a failed Hitachi hard drive, you may be interested in our Hitachi Data Recovery Services. We have been receiving Hitachi HTS5450 hard drives for data recovery since 2010. The majority of them appear to show a similar failing symptom, resulting in access to the data becoming more and more difficult.
After experience recovering several of these hard drives we have discovered that the problem appears to be trouble reading from the disc media. This may initially have been caused by the internal read and write heads writing bad data or the disc media itself suffering some mis-alignment or deteriorated magnetic coating.
Whatever the cause, the rework to overcome this can be a slow and very deliberate process. Anyone with one of these hard drives should make sure to back up regularly and any signs of slow or difficult access, you may want to think about replacing the drive.
If you have a failing 5450 drive, then it is important that you don’t try to fix or repair the drive in any way. It will make things much worse. First try to copy off important files. If that doesn’t work then it may already need a professional recovery process.