Toshiba ex-internal drive (now external) not being recognized

My Acer Windows 10 notebook had a 1 tb Toshiba internal hard drive. A few months ago I replaced that hard drive with an SSD. I now use that hard drive to periodically clone the SSD back to the hard drive for a full backup. During that process, the hard drive is connected to the Acer by a cable from the hard drive to a USB port. All has been fine until last night when the clone process didn't complete. I then found that the plugged-in hard drive didn't appear in File Explorer (it had been drive E). When connected to the USB port, I can feel the disk operating but it's still not being recognized as being connected.

Ideas?

mwr said:

Ideas?

Could be several reasons, please post a screenshot of Disk Management to help in diagnosis.
Disk Management - How to Post a Screenshot of

Hmm, how can I do that when the hard drive isn't recognized by my computer.

mwr said:

Hmm, how can I do that when the hard drive isn't recognized by my computer.

If it is at all functional a hard drive will still appear in Disk Management even if it's not seen in File Explorer.

Only partitions that have been assigned a drive letter can be seen in Explorer. There are many possible reasons for a partition not having a letter, ranging from the partition being intact and just lost its letter assignment to the partition table being corrupt and all partitions have been lost. A screenshot of disk management will show which of those (or other) possibilities may have happened.

Thanks! Here it is. It looks like it's Disk 2.

Thanks. I can see that Disk 2 used to be a system disk as it still has an EFI partition. The rest of the disk space is shown as Unallocated which means that your interrupted 'cloning' (what did you use for that?) seems to have deleted the partition and not got as far as creating another one. Whatever may have been on this drive before is now probably lost.

What do you want to achieve? Would you like a drive with a letter so you can copy files/folder to it? To make yourself a partition with a drive letter so you can see it in Explorer, in Disk Management right-click on the unallocated space of Disk 2 and select 'New simple volume'. Then follow the instructions.

I installed the free version of HD Sentinel and it said the following about that drive:
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There are 2360 bad sectors on the disk surface. The contents of these sectors were moved to the spare area. Based on the number of remapping operations, the bad sectors may form continuous areas. It is recommended to examine the log of the disk regularly. All new problems found will be logged there. It is recommended to backup immediately to prevent data loss.
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Looks like I need to get another drive for the cloned backup. Probably a duplicate of the internal SSD.

- - - Updated - - -

I did a full format on that drive (6 1/2 hours on a USB2 connection), then ran HD Sentinel and got exactly the same result. Anyone have an idea how a hard drive could get so bad after being seemingly fine?

Disk is physically broken. I would discard it.

Indeed, the old HDD has died. Something that has been well used for 3-4 years is not a good choice as a backup drive. The reason does not matter. Such things are random and the chances of death increase with age.

Hi folks

@mwr

How did you connect it as an external drive -- enclosure / sata-->usb connector etc -- these drives need power supply usually if using as external drive -- standard USB connector won't normally have enough "juice" -- another option try a powered hub.

HDD's believe it or not rarely break these days (some do but if they were going to break you usually start getting all sorts of warnings first).

Cheers
jimbo