Correct me if I’m wrong, but manufacturer warranties are not transferrable, so when you bought it secondhand, the warranty didn’t convey to you.
My experience with WD and Seagate has been that they request proof of purchase, which, for me, was my original invoice.
Not sure what you mean.
WD RMA seems to require proof of purchase and serial number.
Perhaps going outside of these “normal” channels for RMA might get you around these requirements, but it seems unlikely they’d accept RMA for any drive without proof of purchase. Maybe in some cases, but in suspect those would be the exception, not the rule.
That said, who is to say how long a drive sat on a stock shelf before initial sale? An unregistered drive could be secondhand, or just wasn’t sold until recently.
I simply meant that I wouldn’t assume a used drive includes a manufacturer warranty. I’d work with the reseller to replace the drive, not the manufacturer.