: An unstable or insufficient power supply is a leading cause. Faulty Adapter
Do not ignore the reboots. Every time your DVR restarts, you lose 2-3 minutes of footage. Over a month, that could be hours of unrecorded activity. Run the diagnostic steps above today. Your security system—and your peace of mind—depends on it. hikvision dvr auto restart problem
The ribbon cable connecting the motherboard to the hard drive is fragile. If it is loose or partially disconnected, the DVR may detect a drive error and reboot to "recover" the storage. : An unstable or insufficient power supply is
: Many Hikvision units have a "Maintenance" setting that reboots the system weekly. Check Configuration > System > Maintenance to see if this is enabled . Over a month, that could be hours of unrecorded activity
: Some firmware versions (e.g., v3.4.100) and specific versions of the Hik-Connect app