Dahua DHI-HCVR5104-S2 serial number is empty 00000..., cannot stop autoboot with UART

damianalex

n3wb
Dec 29, 2025
2
0
Poland
Hi all,
After some power failure my Dahua lost settings. I set all over again, but I noticed that P2P stop working. The reason is that serial number is now empty (00000000000), as you can see in pictures.

I found similar topic on forum, so i I try connect UART to my recorder, to set SN.

I soldered wires TX, RX and GND to junction described "232", as you can see in pictures, set com baudrate to 115200.

When device is booting up I get log, which says "Hit any key to stop autoboot: " and count from 3 to 0.
When counting I try to send via UART <CR> "Enter key", space key and any other, but nothing works, device is still going to normal boot.
I know that TX of my interface is working, because when i loop TX and RX I get echo of my sent messages.

I tried with Putty, RealTerm, Hercules etc. I tried with 5V and 3.3V. Also try change TX and RX, also tried connect TX to 4th pin in junction "232" but this is nonsense, because i think it is just power supply (DMM shows 5V)

I also tried with keyboard connected to USB of device, but still canot stop autoboot.

Full log also attached.

Have you any ideas?

Thanks in advance for helping me,
Damian
 

Attachments

  • empty_SN.jpg
    empty_SN.jpg
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  • mainboard.jpg
    mainboard.jpg
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  • uart_cable.jpg
    uart_cable.jpg
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  • junction_232.jpg
    junction_232.jpg
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  • port_settings.PNG
    port_settings.PNG
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  • stop_autoboot.PNG
    stop_autoboot.PNG
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  • log.txt
    log.txt
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