Check the displayed on your DVR's monitor screen.
The primary software-based bypass for the AHB-8204 HNN motherboard relies on a dynamic time-based algorithm. The system generates a temporary backdoor password unique to the exact day, month, and year displayed on the monitor. dvr model ahb-8204 hnn super password
If your DVR’s firmware date (visible in the system info menu, if you can get to it) is , the nnadmin super password may be disabled. In these cases, you have two options: Check the displayed on your DVR's monitor screen