Hi,
Since you already tried installing just the new drive, I would suggest trying to connect it directly to a windows machine, delete any partitions / volumes and then try partitioning and format, not quick format, on the windows machine. If you get that far, without errors or problems, try deleting the partitions and volumes again and reinstall this single drive in your NAS. I think you may have a bad drive, but most manufactures will ask you to run their diagnostic software to confirm before doing an RMA. If the drive is bad try returning it to the vendor asap as they will give you another new drive, it's refurb with the manufacturer. Good luck.