Flashing lights on THREE WD drives... why?

I am all of a sudden having issues with three WD drives, all are My Books (two Essential Editions, one Home Edition). The Essential Editions have light rings on the front and the Home Edition has the vertical light.  The problem is that the lights on all three flash when connnected to power and are not recognized by Mac, nor do the drives start spinning. After trying every fix I could think of, I talked to WD technical support, which suggested the same things I had already done, and concluded “there seems to be a problem.”  Well, yes, I knew that.  So I come here to see if anyone can figure out this puzzle.

Not sure what all information will be pertinent, so I will give it all.  I have been moving to a new Mac.  One of these drives I used on the new Mac to transfer data.  The other two were not ever connected to it but worked fine on the old Mac.

When I tried plugging one drive in this morning, I got the flashing light and Mac wouldn’t recognize drive.  Same on the others, including the one that had been used before on this computer.

I tried changing power cords… the lights continued to flash, but at a slower speed.  Not sure what that means.

I tried changing computers, same deal… not recognized.

I have one other My Book that works fine.  I tried its power cord on the non-responsive drives and no change.

We have had no power surges or similar problems that I know of.

So, I have switched power cords and computers, I have tried various outlets.  Nothing seems to matter.

These couldn’t have just magically all failed at the same time, right?

If they have not failed, how can I get them to work?  If they have failed, what the heck could have caused it?

Am I missing something I can try?  Any advice out there?  Thank you!

By any chance are those drives the exact same capacity connected simultaneously?