3.0TB USB Drive for ReadyNAS Pro Backup

Turns out my Hitachi USB drive failed suddenly after many months of hitch free Frontview backups. The ReadyNAS Pro recognized this drive as USB2. I replaced the USB drive with a new Seagate Expansion 3TB USB 2.0 drive. The ReadyNAS Pro recognizes this drive as USB3. Frontview backups are now working flawlessly again.

For extra security, I'd like to backup to a 2nd external 3TB drive. I'd like to store this drive offsite and swap with my Seagate drive for Frontview backups.

Convinced that my Hitachi USB drive was salvageable, I broke open the case and stripped out the bare Hitachi drive. After testing the drive on my PC, I confirmed that it was working. Looks like the power supply on the USB drive died.

After formatting the drive (GPT and NTFS), I installed the bare drive in a new Thermaltake (ST0020U) Max5G USB 3.0 hard drive enclosure. After testing once more on my WIN7 machine, I plugged this into the ReadyNAS Pro USB port.

For some reason, the USB drive is not recognized in either the front or back USB ports. It's as if there's no USB drive plugged in at all. Remember, the same drive (when installed in the Hitachi USB enclosure) worked perfectly fine before the power supply failed.

I'm mystified as to what's gone wrong. Any suggestions on getting my Hitachi 3TB USB drive recognized by the ReadyNAS PRO?

Thanks,
Herb...