1) It maybe that the system is unable to start due to insufficient power supply. - Please change another working power supply to connect the system to try.

2) If you installed an internal hard disk in the system, the hard disk has bad sectors may also cause this problem. - Please disassemble the rear cover of the DVR / NVR system and unplug the date wire and power wire of the hard drive to try.

3) If neither of the above steps work, it sounds like the DVR /NVR system is experiencing a firmware crash. This sometimes occurs if the power is disconnected without performing a proper shutdown through the menu. Manually applying a firmware update should help it to function normally.

Please provide us the model number of your system, on the outside of the DVR / NVR, there should be two labels featuring the model number and device ID of your DVR / NVR. If you could please respond with these details, we should be able to provide you with a link to the firmware update and some directions on how to proceed.

If possible, pictures of these labels would be ideal to ensure we locate the appropriate firmware for you.

Please let us know if you have any questions:

Support Email address:  service@zositech.com

Our Facebook:  https://www.facebook.com/ZosiTechnology/

Support center: support@zositechhelp.zendesk.com