Unable to set NVR to factory default

[KevinLK]

Hello, (safe me)

I have an issue with an NVR where I dont know that master password from (admin).
I have other regular admin accounts but I'm unable to set the recorder to factory default and resetting the password.
If i reset it now from the NVR all settings are lost but not the password.

Here are the things I have tried:

1. Unplug the power leave it for 10-15sec offline, press reset button see picture (red circle). for 30 seconds and more release it and nothing happends.

2. Tried to get master password from dahua recorder date and time.
3. Tried to set it back to default from web and NVR, this only resets the settings not the passwords.
4. Changing the password from another admin, cant change the admin password because i dont have to old password.

Thanks in advance.

Here are my specs:

Device type: DHI-NVR4104-P-4KS@
4 channel.
System Version: 3.215.0000000.1, build date 2017-09-02

 

[alastairstevenson]

1. Unplug the power leave it for 10-15sec offline, press reset button see picture (red circle). for 30 seconds and more release it and nothing happends.

Did you keep the reset button pressed while you powered it on for maybe 40 seconds or so?

 

[KevinLK]

Did you keep the reset button pressed while you powered it on for maybe 40 seconds or so?

Yes,