TL;DR HDD is dying, need a solution to transfer the data to another drive
In march 2021, I bought a 8TB Seagate Barracuda Compute on amazon, the drive was delivery in a shitty state (not even boxed) but functional.
Yesterday the drive is now giving the last breath, sometimes pc pc can only go past post if the drive isn’t installed, had to buy an SSD (Samsung 870 QVO) that will only be delivered in December
Now I’m just waiting to get the SSD so I can (hopefully) transfer everything from the HDD to the SSD
https://www.gnu.org/software/ddrescue/
…Or restore from your backup. You do have a backup, right?
Oh you don’t? Well, your new plan to purchase multiple drives and not just one drive is so that you’ll fix that you don’t have a backup, right?
Does it show up on the system? If you want to diy it I’d give ddrescue a shot and see if it can get most of the data. DDrescue is made for failing drives and can restart, and try to get bad parts of the drive later on.
Data recovery is not really something you should DIY unless you are fine with losing the data. Chances are high you will make professional recovery more expensive or outright impossible by tinkering yourself.
Your best bet is to make a disk image. For this the HDD will be read like a vinyl record from beginning to end. For a file copy the read head usually has to seek around a lot to read all the file (fragments) bit by bit.
You’ve changed the sata cables and tried a different port yes?