What to do if hard disk drive can't be recognized?
You can format the hard drive before using it.
If DVR or NVR can't recognize HDD, we can try methods below.
Install hard drive and put hard drive close to your ear to check if you can hear some noise
1) Open the cover of DVR/NVR. Uninstall and install HDD for several times.
Note: Before installing the hard drive disk, please power off the system if it is on.
2) Unplug and plug data and power cable of HDD.
4) Restore DVR or NVR to factory setting.
5) Try a spare DVR/NVR or HDD if you have.
6) Send your NVR version to the support, upgrade NVR and tell us the result.
if you can not hear some noise
1) Change an adapter of DVR/NVR with larger output.