Once you find a working firmware, immediately back it up. Use the DVR's "Export Log" or dd command via SSH to dump the flash memory. Store that .bin file in three places. In the security industry, a working firmware file for a v402r11 is as valuable as the hardware itself.
Need specific file links? Because firmware changes weekly and search engines delist illegal hosting sites, visit the OpenIPC or CCTV Forum wiki and search for "v402r11 approved firmware list" for live, verified mirrors. v402r11 h264 h265 dvr nvr firmware download work
In the world of professional video surveillance, few model identifiers cause as much simultaneous excitement and frustration as v402r11 . This cryptic string of characters represents a hardware platform found in countless cost-effective DVRs (Digital Video Recorders) and NVRs (Network Video Recorders). These devices support both H.264 and H.265 compression standards, but they are notoriously picky about firmware. Once you find a working firmware, immediately back it up