Disclaimer: I work for WD/HGST in Enterprise Support. Another problem we see a lot with 'refurb' purchases (especially SAS models) is that the drives can be OE

Disclaimer: I work for WD/HGST in Enterprise Support. Another problem we see a lot with 'refurb' purchases (especially SAS models) is that the drives can be OEM types made to order for use in a vendor's SAN/NAS enclosure; the OEMs often load up their own firmware and tweak the hardware design, so generic code may be incompatible and can't be installed. Buyers try these drives with their own hardware and when they don't work (at all or partially) they come to us for a firmware 'fix'. Warranty and support issues for OEM drives are handled by the company for whom the drives are made, and they may not cover second-hand drives purchased through certain channels. A customer the other day had around $8K of 'refurb' drives that wouldn't work in their storage enclosure and we had to refer them back to their auction-site based supplier.