Hey there, Mastermmm.
I'm really sorry to hear about the problems you're having with those drives. Do you have any data on them which you need to recover? Are you sure they've been properly formatted for Mac OS X?
I'd recommend that you check that link and follow all the suggestions, to see if they help you figure out what might be wrong here:
WD external hard drive is not powering on or is not recognized on a Mac system.
You could also try testing the drive for errors, even though it would be quite an unfortunate coincidence for 2 drives to be having issues at the same time:
How to test a drive for defects or problems on a Mac.
Please let me know how everything goes.
Boogieman_WD