Dahua ADT DVR Password Reset

[rdagger 0]

I have a Dahua DVR5108C (branded by ADT). I’m trying to reset the password because I don’t know the current admin password. The current displayed date is 02-21-2000. I contacted Dahua and they gave me two passwords based on the date but neither worked. They said ADT probably modifies the firmware. I had no luck when I called ADT (I no longer use their service). The unit refuses telnet connections on port 23. I tried several 6 digit combinations including 000000 with no luck. I tried removing the battery but it didn’t work. Any ideas?