After years of faithful service I now can't use my WD Pocket Passport. I have it plugged in to the USB port in the back of the case and a scanner in the other USB port. I've switched them, switched cables, no joy.
If I have the HD plugged in to the computer and to the power strip then try to boot the boot sequence hangs, resumes correctly as soon as I unplug the USB cable (from the HD).
If I plug the USB cable into the HD while the computer is on it immediately shuts down!
The same cable works correctly for my camera, ebook reader and mp3 player.
Does it work when you connect it to another system? You've determined that the USB cable is fine, but what about the WD Pocket Passport itself?