Dahua NVR4108HS-8P-4KS password reset - already tried nearly everything

K

konne

n3wb
Jan 20, 2025
7
2
NZ
Hi,

thanks for that great forum and I tried already everything that I found in that forum.
I like to password reset this device and I have no access to the recovery email.

1. try to use K1 switch hold during power on, later, long, short,...
2. password per day calculated on the visible day in the CCTV
3. removed the batterie and tried the password 000000000000 and 668648
4. searched on the board for J1 or any other thing to connect the pins to reset.
5. reach out to the dahua support, they just told that this device does not have an easy switch to hard reset

If anybody know how to connect rs232 to that board I have would also have soldering equipment to do it.

Thanks for any ideas / help.
 
I forgot to attach the pictures.
 

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konne said:
Hi,

thanks for that great forum and I tried already everything that I found in that forum.
I like to password reset this device and I have no access to the recovery email.

1. try to use K1 switch hold during power on, later, long, short,...
2. password per day calculated on the visible day in the CCTV
3. removed the batterie and tried the password 000000000000 and 668648
4. searched on the board for J1 or any other thing to connect the pins to reset.
5. reach out to the dahua support, they just told that this device does not have an easy switch to hard reset

If anybody know how to connect rs232 to that board I have would also have soldering equipment to do it.

Thanks for any ideas / help.
Click to expand...
Hi mate, from what I can see your serial port connection is j6, BLACK is GND, RED is TX, GREEN is RX. Don't take my word for it though, I've seen some weird pinouts on Dahua boards, so check the pins with a multimeter. Connect the serial to the computer with USB UART if you don't have a serial port and start your telnet client. I personally use SecureCRT, but you can use PuTTY or any other one. Port configuration as on the picture. Start the NVR, you should get some output in the terminal window (if not re-check the connections, make sure GND, RX and TX are connected where they should be). Press Ctrl+C to stop the boot and enter the command eracfg. Restart the NVR and you should be ready to go. The command deletes all the setting for cameras, users, passwords etc, essentially it's a factory reset. Hope that helps, I struggled quite a lot before finding the information how to do it.
 

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So I don't know, I would personally put the battery back in, The try a reset again. Looking at the picture if the Reset button was there it looks like the C39 cap is there and NVR could reset. Problem is they can be tricky but the battery needs to be there. Make sure to solder the battery back in right direction..

Might need to try a few times.

First I would try after a boot up after adding the battery back. Press and hold the reset button for 15 seconds, Using a stopwatch might be important as the times need to be just right.. Again holding the button for 15 seconds, remove power while holding the button, keep holding for 15 seconds after power is removed and add power back while still holding the button. Then 15 seconds after should hear a beep.. Even if you don't hear the beep after 15 seconds of returning power keep holding the switch. However if the Beep comes after the system has come online then the reset failed.

Try again.

Second. if you tried and know that the button was pressed the whole time from start to finish then try same method but 10 seconds rather then 15..

Third, If that fails 2 tries. Then could try with system off.. Press and hold button for 10 seconds or 15 try them both. But same idea just starting from no power.. Press and hold let say 10 seconds. Then power on still holding the button and keep holding the button. You are looking for a Reset beep that should happen before the normal I am online Beep happens. You will know the system has reset because it will be asking for you to setup the NVR..
 
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baggins73 said:
Hi mate, from what I can see your serial port connection is j6, BLACK is GND, RED is TX, GREEN is RX. Don't take my word for it though, I've seen some weird pinouts on Dahua boards, so check the pins with a multimeter. Connect the serial to the computer with USB UART if you don't have a serial port and start your telnet client. I personally use SecureCRT, but you can use PuTTY or any other one. Port configuration as on the picture. Start the NVR, you should get some output in the terminal window (if not re-check the connections, make sure GND, RX and TX are connected where they should be). Press Ctrl+C to stop the boot and enter the command eracfg. Restart the NVR and you should be ready to go. The command deletes all the setting for cameras, users, passwords etc, essentially it's a factory reset. Hope that helps, I struggled quite a lot before finding the information how to do it.
Click to expand...
Hi, thanks for your suggestion
I tried it, but I had no success. I did not received any data on the terminal.
 
Revo2Maxx said:
So I don't know, I would personally put the battery back in, The try a reset again. Looking at the picture if the Reset button was there it looks like the C39 cap is there and NVR could reset. Problem is they can be tricky but the battery needs to be there. Make sure to solder the battery back in right direction..

Might need to try a few times.

First I would try after a boot up after adding the battery back. Press and hold the reset button for 15 seconds, Using a stopwatch might be important as the times need to be just right.. Again holding the button for 15 seconds, remove power while holding the button, keep holding for 15 seconds after power is removed and add power back while still holding the button. Then 15 seconds after should hear a beep.. Even if you don't hear the beep after 15 seconds of returning power keep holding the switch. However if the Beep comes after the system has come online then the reset failed.

Try again.

Second. if you tried and know that the button was pressed the whole time from start to finish then try same method but 10 seconds rather then 15..

Third, If that fails 2 tries. Then could try with system off.. Press and hold button for 10 seconds or 15 try them both. But same idea just starting from no power.. Press and hold let say 10 seconds. Then power on still holding the button and keep holding the button. You are looking for a Reset beep that should happen before the normal I am online Beep happens. You will know the system has reset because it will be asking for you to setup the NVR..
Click to expand...
thanks for this details, I tried it really often with stopwatch and all your methods, no success
 
Confirmed the pinout of the serial interface, make sure you are connecting to the correct port number of the uart (check in device manager). If no output change RX and TX and try again. It works 100%, sometimes the serial adapter plays up. Hope you sort it out.
 

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baggins73 said:
Confirmed the pinout of the serial interface, make sure you are connecting to the correct port number of the uart (check in device manager). If no output change RX and TX and try again. It works 100%, sometimes the serial adapter plays up. Hope you sort it out.
Click to expand...
Hi, i already changed rx and tx and I can confirm that I had the right port number.
I will try it again, the port is just annoying small to solder / connect on
Did they maybe a longer time ago use a different baud rate or was it always 115200 / 8 / N / 1
 
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