: On your recorder, navigate to Main Menu > Info > Version .
If you mix old analog H.264 cameras with new 4MP/8MP H.265 IP cameras, the V402R11 firmware is the only unified kernel that manages both streams without crashing. v402r11 h264 h265 dvr nvr firmware download high quality
| Problem | Likely Cause | Solution | | :--- | :--- | :--- | | "Update file mismatch" | Wrong board version | Download firmware specific to your PCB number (e.g., V4.02.R11.5 vs .4) | | Camera shows "H.265 Not Supported" after update | Main stream settings reset to H.265+ | Manually set encoding to H.264 or standard H.265 (not H.265+) | | DVR freezes at boot logo | Corrupted partition | Enter bootloader (hold Reset + Power). Use TFTP recovery or serial console. | | Lost admin password | Firmware reset credentials | Use default passwords: 12345, admin, or 888888. If not, use OEM password reset tool. | : On your recorder, navigate to Main Menu > Info > Version
This firmware is provided for archival and maintenance purposes. We are not responsible for hardware damage resulting from incorrect installation or incompatible hardware flashing. Always verify the specific board number before proceeding. Use TFTP recovery or serial console