How to check the X820
Check X820 via Desktop computer (Recommend)
Because X820 can be as the mobile hard disk. so please connect your X820 with you desktop computer or laptop with . then open the 'Computer Management', check if found new disk.
Please try formatting the hard drive if it still cannot be recognized.
Or run the following command to check it:
lsblk fdisk -l
Check X820 via Raspberrypi board
Please connect the Raspberry Pi and X820 motherboard correctly, you may refer to it here.
NOTE: Please use a good power supply, otherwise you may encounter some unpredictable problems!!Important!!!