Hello, this may seem a bit odd. It started when I was helping my brother with an upgrade, and during the process of shuffling around the hard drives in his desktop, we found one that had apparently failed at some point, but he hadn't noticed because it didn't have anything he needed on it. We pulled it as part of the upgrade, but with the intention of going back to figure out what was up with the drive, what was on it, and if it was something that we'd be willing to use after some fixing up.
Anyways, the drive itself is a 2TB Seagate Barracuda, model no ST2000DM001. Step one of seeing what's up with it was to fire it up in an external drive bay linked to the windows 10 PC via e-sata. After turning on the drive, I opened Windows Explorer and the drive was listed under devices and drives, but without the bar indicating how full it is. When I tried right clicking it to check property information, the click stalled as an hourglass. Opening Disk Management opened the window, but it's interior remained blank and unresponsive until I turned off the drive at which point it immediately started working.
So, with what I've learned so far, what are my options for trying to diagnose this drive and see if it's fixable?

Could you give us terminal output?
ps Most likely you can't fix hard drive.

What noises does the harddisk make?
Can you measure the voltages on the various pins?
Can you provide a photo of the PCB?
Could you try to attach it to a Linux PC and run dmesg to get a little more information about it?

Give the model, it's most likely a failure related to the media cache or auto-reallocation functions. It's very common with these and will cause the drive to get stuck busy despite recognizing normally in BIOS. Using a tool like PC-3000 or MRT it should be pretty easy to disable either and get the drive functional enough to extract the data.

Most likely it'll also have some areas of bad sectors as that's usually what triggers this issue to begin with.

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