External WD won't connect

[apostolosdt]

I have an external WD 4TB where I store music and videos connected to an iMac 2017 running Ventura. When I tried to backup it on another similar WD, it suddenly disconnected and when re-connected, it worked erratically until it stopped being recognized. Funny thing is the DriveDx sees it working at 100% health with no errors.

I know such 4TB disks are prone to errors, from my previous experience. My question is this: any way of saving its contents before I format it? Perhaps any software to extract some precious docs? Thanks!

 

[Mike Boreham]

I have an external WD 4TB where I store music and videos connected to an iMac 2017 running Ventura. When I tried to backup it on another similar WD, it suddenly disconnected and when re-connected, it worked erratically until it stopped being recognized. Funny thing is the DriveDx sees it working at 100% health with no errors.

I know such 4TB disks are prone to errors, from my previous experience. My question is this: any way of saving its contents before I format it? Perhaps any software to extract some precious docs? Thanks!

If it contains really important non-backed up data, I would not try anything myself, but take it to a specialist recovery company.

If you are prepared to risk making things worse, a few ideas:
- DriveDx is seeing it, but it is not mounting….does Disk Utility see it? Unmounted obviously. Click “show all devices” option in DU. If DU does show it unmounted, can you mount it from DU?
- If DU is seeing it you should be able to run First Aid on it. DU unmounts for FA so being unmounted shouldn’t matter.
- You could disassemble the drive to extract the HD and connect it via another means…put in an enclosure or toaster connector. If the 4TB drive is a portable RAID device with 2 x 2TB 2.5 inch drives this won’t work.
- If it is a 3.5” drive with an external power supply, do you have a second identical drive with another power supply you could swap over?

 

[bogdanw]

Is it HFS+, APFS or ExFAT?
For the HFS+ and APFS, try "Repair a storage device in Disk Utility on Mac" https://support.apple.com/guide/disk-utility/repair-a-storage-device-dskutl1040/22.0/mac/13.0
For ExFAT, repair it from Windows.

 

[apostolosdt]

If it contains really important non-backed up data, I would not try anything myself, but take it to a specialist recovery company.

If you are prepared to risk making things worse, a few ideas:
- DriveDx is seeing it, but it is not mounting….does Disk Utility see it? Unmounted obviously. Click “show all devices” option in DU. If DU does show it unmounted, can you mount it from DU?
- If DU is seeing it you should be able to run First Aid on it. DU unmounts for FA so being unmounted shouldn’t matter.
- You could disassemble the drive to extract the HD and connect it via another means…put in an enclosure or toaster connector. If the 4TB drive is a portable RAID device with 2 x 2TB 2.5 inch drives this won’t work.
- If it is a 3.5” drive with an external power supply, do you have a second identical drive with another power supply you could swap over?

Thanks! DU does see it, unmounted; it's APFS and DU cannot mount it ("enter error 49218"). First Aids failed, too. It cannot be disassembled as it's an enclosed standard 2.5" disk.

No external power supply either. But---"idea"---that might be the problem. Insufficient power during heavy use. And as it contains no crucial material, I think I will format it right away.

 

[Mike Boreham]

Thanks! DU does see it, unmounted; it's APFS and DU cannot mount it ("enter error 49218"). First Aids failed, too. It cannot be disassembled as it's an enclosed standard 2.5" disk.

No external power supply either. But---"idea"---that might be the problem. Insufficient power during heavy use. And as it contains no crucial material, I think I will format it right away.

Yes, if bus powered 2.5", power might be the problem. You mentioned it happened when you tried to back it up to a similar drive...so maybe two bus powered drives near the power available limit at the same time was the problem. Is the drive OK if used on its own? It sounds like you have had the drive for a while and it has gone bad so maybe something is amiss, in which case formatting it might not solve it, so I would treat it with caution (well backed up) going forward.

I am not familiar with the drive but I used some Seagate 4TB portable bus powered drives for a while and these definitely were packaged 2 x 2TB Raid 0 drives. There were sometimes power issues with these and some of this type were supplied with a branched USB cable which could plug into two ports. All drives can be disassembled with varying degrees of difficulty and sometimes not reversibly!

 

[apostolosdt]

Thank you all for your help. Eventually, I formatted but I learnt my lesson---never running two ext volumes when not wire-powered!