The D4-320 has been tested with multiple hard drives, multiple USB-C cables, and multiple computers. After insertion, the hard drives spin and the indicators light up, but the computer still cannot recognize them. What should I do?

Applicable Models

D4-320

Focus on checking whether the hard drives are properly installed — manually push the hard drive tray inward to ensure it is fully and securely seated.
If unsure about the correct installation, visit the official quick installation guide to view the hard drive installation instructions for the corresponding model: https://support.terra-master.com/quickguide/