WD20EARS passes SMART test but inaccessible

My WD20EARS-00MVWB0 (firmware 51.0AB51)  suddenly disappeared from my drive list as I was in the process of moving some backup data off of it to another drive.  I went ahead and mounted it in an external enclosure for troubleshooting. 

It passes the SMART test and says health status = “Good” but fails the other Quick and Extended Data Lifeguard tests.  It’s making normal seeking sounds to my untrained ears.  In Disk Management it’s appearing as unallocated space, as if it were a fresh unformatted drive.

I’ve gone ahead and started the RMA process but if anyone has ideas on other options to try to recover some data, let me know.  Not the end of the world but would save me some time.

One single word for you mate: R E P L A C E.

Have you unplugged it, booted the PC, shut down, then plugged it back in ?

You using XP ?.. they need “alignment”.  It’ll work and then go flaky.