On Tue, 04 Sep 2018 19:23:48 -0500, Charlie Hoffpauir
wrote:

On Wed, 05 Sep 2018 00:19:26 +0100 (BST), "rp"
wrote:

By swapping the drive over you also reseated the SATA connector I
presume. Maybe that was loose and causing errors.

Thanks, I never considered that. It's one of those locking connectors,
but I guess it could still be loose or have some corrosion.

If that was the issue, you'd be able to see it in the Event logs. Use
Event Viewer to check it out.