Thanks for your reply.
The best advice for being able to repair your Hitachi hard drive with a software utility is to consider investing in Disk Warrior 4.3.
I have used this software for over 5 years and it has honestly worked for me (and I am not exaggerating) at a 95% success rate in my clients and my own hard drive repairs.
Disk Warrior is an excellent resource for resolving directory corruption and damaged volume issues yield errors in Disk Utility such as "Invalid Node Structure" and "Catalog-B tree" errors which are very common errors with Mac OS Extended (Journaled) formatted hard drives.
Disk Warrior 4.3 can not only repair damaged directories, but also rebuild the damaged or corrupted directory or volume, making it functional again, without loss of your data on the hard drive.
So this is my recommendation, and I definitely suggest you take a serious look at this product in order to help resolve the issue with your Hitachi external hard drive.Review Disk Warrior 4.3
Let me know if this helps.
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