Can't add Seagate drive to TS-2.0TGL/R5

[Tanoshimi]

I have two TS-2.0TGL/R5. I bought them used.  One has 4 working drives, and is fine.  The other had two working drives and two that didn't work.  I purchased a Seagate 500GB drive (same size as the ones that work).  When I put it in, and reboot the system, I get the error that no drive is recognized there, so I can't format it.  Could this be because the drive may already be formatted for NTFS?  The other drive that doesn't work is recognized as an unformatted drive, but all attempts to format it fail. 

 

Any suggestions on how to get the new Seagate drive to be recognized, formatted, and used?

Any reasons why the other drive is recognized, but not formattable?  Bad drive?

 

-Chris Joy