Hi, trying to resurrect an old My Book Premium Edition II 2TB drive.
I powered up the drive and the circular Blue LED outer ring is steady ON and I can hear the disk spinning. I connected using USB/FW400/FW800 but none of the connections make the disk appear in Disk Utility ‘Show All Devices’ macOS 11.2.3 Big Sur. I recall that older OS X had to install a driver from an Install CD that I no longer have.
On macOS Big Sur I’ve installed the WD Drive Utilities app and it does ‘see’ my other WD Elements extern. USB drive.