Suppose the listing said “recertified.” SMART says 12 hours. The first self-test passes. I'd save all three, because the test result answers a different question from how many hours that disk has spent spinning.
We keep drive-arrival records at TechFuelHQ. There’s a field for the hours from SMART and a separate one for the FARM log on Seagate drives that expose it. No FARM log? Leave it blank. Writing down zero would turn a reading you never took into a claim the disk was new.
If you've sent a used disk back, what tipped the decision? I'd be interested in cases where something changed between unpacking it and finishing the first long test. No serial numbers needed.