Unable to erase or mount external hard drive used for Time Machine

[vitolanzafame]

Hi all,

I'm using a 1TB ssd external hard drive (on my mbpro retina 2013 Catalina) and have been happily backing up to time machine with it for over a year.
Yesterday however, it is no longer recognised in Finder.

In disk utility however, it IS recognised, but is greyed out. It say's it's unmounted, but I'm unable to mount it or erase it, or do anything with it. I ran first aid and it found an 'incorrect block count' for a file, but it was unable to repair it.

I've been trawling forums for hours and tried various 'fixes' including restarting the mac, turning off time machine, using terminal to try and mount it, etc.

I read somewhere that Time Machine can cause errors relating to 'snapshots' which i don't really understand. Does this ring any bells with anyone, or anyone have any other possible solutions?

Any help very much appreciated.

Vito

 

[BrianBaughn]

How is it connected (housing/cable) and can you connect it some other way to check?

 

[Madhatter32]

Sounds like a corrupted external hard drive. This happened to me a few years ago. I ended up wiping the drive, running a repair with Disk Utility, and making a fresh TM. This obviously will not help you if you need the old TM snapshots.

 

[vitolanzafame]

How is it connected (housing/cable) and can you connect it some other way to check?

its connected with a usb cable - A male to A male. Only option for connection. I don't have any other cables to check but I don't think the cable is faulty as the drive is lighting up and is partially visible in Disk Utility. And when i try and action things in disk utility the light starts blinking as it does when its doing something .

 

[vitolanzafame]

Sounds like a corrupted external hard drive. This happened to me a few years ago. I ended up wiping the drive, running a repair with Disk Utility, and making a fresh TM. This obviously will not help you if you need the old TM snapshots.

Yes - this is what i'm also thinking.
I am happy to wipe the disk, but I can't!
Disk Utility won't let me erase it.
Does anyone know another way to erase the disk?

 

[Madhatter32]

Yes - this is what i'm also thinking.
I am happy to wipe the disk, but I can't!
Disk Utility won't let me erase it.
Does anyone know another way to erase the disk?

I also have an older Intel based Mac. So, I booted into recovery mode by pressing Command-R at startup. I then went to disk utility while in recovery mode and wiped the drive. For some reason, for me at least, disk utility in recovery mode was able to mount the drive even when it could not while using the disk utility in the normal boot mode. It's worth a shot.

 

[BrianBaughn]

its connected with a usb cable - A male to A male. Only option for connection. I don't have any other cables to check but I don't think the cable is faulty as the drive is lighting up and is partially visible in Disk Utility. And when i try and action things in disk utility the light starts blinking as it does when its doing something .

You didn't say what kind of enclosure it is. Is it a sealed unit or can you take the SSD out?

The enclosure's electronics could certainly malfunction in a way as to make the SSD inaccessible or corrupt the drive in that way. You could pop it into another enclosure or use a SATA to USB3 cable to see which it is.