a、 Please check whether the hard disk capacity is more than 3TB, generally recommend hard drive below 3TB, Seagate brand with best compatibility.
b、 Please check whether the hard disk is damaged, or the hard drive data cable and the power cord is connected well.
c、Check whether there is a disk error, if it is a logical error, please delete the partition information after the hard drive attached to the computer or take the hard drive back to maintain and linked back to the host service, taht can be normal. If it is physically damaged, replace the hard drive.
d、 Whether disk cartridge is good contacted.