Dahua DHI-HCVR4116HS-S3 – UART / Flash chip help (reset issue)”

rimohad

n3wb
Aug 31, 2025
1
0
Bulgaria
Hello everyone,

I have a Dahua DVR DHI-HCVR4116HS-S3 that I am trying to recover.
Unfortunately, it is stuck and I cannot access it anymore, so I am trying with UART / TTL and possibly flashing with CH341A + SOIC clip.

What I have tried so far:

Found header pins (likely UART) and measured voltages:
• GND = 0V
• VCC = 3.3V
• One pin ~2.3V (possible TX)
• One pin 5V (ignored, not used)

Tried USB-TTL (CH340/CH343) at 115200 8N1 but no console output.

Installed CH341A programmer drivers (for backup plan with SPI flash).


What I need help with:

Exact pinout of the UART header on this model, or confirmation of TX/RX pins.

The exact flash chip number used on this DVR (so I can prepare for dump/flash with CH341A).

Any advice if Dahua has locked/disabled UART on this series.


I also have other Dahua devices, but if I can’t get support for this DVR, I may switch to Hikvision or another brand.

Thanks a lot in advance to anyone who has worked with this board!