I'm hoping someone can shed some light on an issue I'm experiencing with the hard drive mentioned in the subject line. Apologies in advance for the long post—just trying to include all the relevant details.

I purchased this drive 20 days ago to use as an internal backup disk for my desktop. I initially formatted it as NTFS and copied about 7 TB of backup data to it. After successfully transferring the data, I powered off the desktop and didn't use it for 3–4 days.

To my surprise, when I turned the system back on, the drive no longer appeared in Windows. I tried swapping the power and data connectors with ones from known working drives, but the drive still wasn't spinning.

I then connected it to an external enclosure. This time, Windows Disk Management recognized the device, but it was listed as "Unknown" and "Not Initialized." Attempting to initialize it resulted in a Windows error.

At that point, I requested an RMA from the seller and packaged the drive to return it. However, a couple of days later, I realized there were some important files on the drive that I hadn't backed up elsewhere. So, I decided to try it again in the external enclosure—and surprisingly, it started spinning and was recognized by Windows. I began copying the files, but after several hours the copy process failed, and the drive stopped spinning again.

I disconnected the drive, waited a few hours, and tried once more—but this time, it wouldn’t spin at all. I left it alone for another couple of days, tried again, and it started spinning once more.

So my question is: what could cause this behavior? Why would the drive require such a long rest—days, not just hours—before it would start spinning again?

Thanks in advance to anyone who might have some insight or suggestions!

attach serial port and post log, that may be informative...

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Adatmentés - Data recovery

Thanks for the reply.
So, when I attach the disk with the USB enclosure, in Windows Event Viewer, the only thing I see is the event with error
"The IO operation at logical block address 0x800c000 for Disk 7 (PDO name: \Device\000001c5) failed due to a hardware error."

sorry, i wasn't clear enough it seems.
the drive has a serial port beside the sata connector (4 pins), there are topics dealing with how to connect an usb-serial adapter to this port, and check what the drive spits out through it in hyper terminal or other terminal emulator program. You need an adapter capable of 1.8V signal levels. Grab the log in the terminal prog and post it here.
pepe

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Adatmentés - Data recovery

Examine the drive's FARM log with SeaChest or smartmontools. Maybe there will be a clue.

https://forums.servethehome.com/index.php?threads/seagate-farm-new-monitoring-options.46879/

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A backup a day keeps DR away.

@pepe, thanks again! I’ll see if I can get my hands on an adapter to retrieve the logs.

@fzabkar, I appreciate the tips. At the moment, it looks like I’m in the “2-day window” — the drive isn’t being recognized by Windows, and although SeaChest lists it, trying to access any info results in an error.

I’ll give it a couple of days to see if it spins up again, as I mentioned in my original post.