WD My Book drive won't boot

First, my hard drive what mount and unmount while in use and I realized it was the bad cable that came with the unit.  When I jiggled it, it would throw off the drive.  I used my own chord and it began working for a few weeks.  Now, it doesn’t mount.  I hear it spin when I put the cable in, but then it dies.  I have tried multiple cables.  My usb drives both work.  I have tried turning off my computer and turning it on and resetting the connection.  The drive does not appear in Disc Utility and it does not appear on the System Profiler when I have it plugged in.  I have not installed any new software in my computer during the time it went from functioning to not functioning.  Any suggestions.  I’m using this as my Time Machine and am now thinking I made a big mistake.

I have the same problem- we took it to the mac store & when connected to their laptops it caused them to restart (it failed to mount) . Mine purrs & the fails to mount. All my photos are on this . What do I do to recover them & other things?