1TB My 4 year old Book Essential dead corroded tracks on Circuit Board

Cranked up the computer a couple of mornings ago and noticed the 1TB wasn’t listed.
Checked the usual suspects, USB cable, power voltage etc.
All diagnostics confirmed the 4yr old 1TB had flat lined -----------

Opening the unit I discovered 2 circuit boards drive the internals,
both had been effected by corrosion, apparently introduced during
manufacture of the circuit boards.
The first WD drive to actually fail in over 25 years.
Disappointing : yes.
Would it stop me from purchasing another WD drive : certainly not.

This is most unfortunate. Do you have a backup of the data stored within the unit?

Yes: Fortunately I used the 1TB as a secondary back up. (Archival file)

Both private and current work files are kept up on several USBs.