I have two WD Passport drives, one a 500gb and a 320gb. Just recently they have stopped showing up on my file manager’s when I plug one or the other into a usb port. I have tried to access them using PDExplorer, XPlorer (both commercial file mangers that used to recognize them) as well as Windows Explorer. None of the three show either of these drives, but do show and recognize a different brand external h.d. I sometimes use. I ran the WD diagnostic software, which did recognize them, and they passed the quick test.
How can I get my file managers to see them again?