The Dahua unbricking procedure is another carefully kept Dahua secret, because you wouldn't want satisfied customers, would you?
Here's the deal.
There's a simple serial interface on many devices called TFTP that's used to load files when the rest of the firmware may not be working. Dahua uses this on their NVRs, and it appears they include it on their cameras as well. I've found the connectors on the 2100 and the 3300C that appear to be the right ones, but haven't tested it, because of the risk of bricking the camera.
Unfortunately, this is not for the technically timid, and it's not a sure thing even for the hardware hackers.
Here's the basic procedure used for NVRs, some of which have a serial port on the chassis:www.dahuasecurity.com/download/TFTP%20upgrade%20instructor.pdf
This doesn't work on the cameras, as the serial connector pins are pinged during the boot, but you can't see what's going on with a terminal program. It's possible they do it like Hik, where it automatically does the upload during boot if everthing's connected.
To try this, here's what you'd need:
- The full set of files, unzipped into the directory of your choice.
- A tftp server. Here are 2 good choices:http://tftpd32.jounin.net/
- Free open source server; I use this to upgrade firmware on my corporate switches.http://www.solarwinds.com/products/freetools/free_tftp_server.aspx
- people like it; requires registration to download.
The NVR procedure calls for the ncom program, but it appears not to use it on the cameras. I use teraterm on Win7 as a general comm program.
- A serial port on your PC. Most modern PCs don't have serial ports, so you'd need a USB to serial adapter. There are lots of them out there, like this one:http://www.newegg.com/Product/Product.aspx?Item=N82E16812188102
- A serial cable that can be connected to the small pins on the board. I cut a serial cable and used some tiny clip leads to connect to the pins.
On the 3300C, they look like this, and on the 2100, they're smaller. I've verified the 3300C connector is talking to the serial port, but haven't on the 2100 yet:http://maxicon.com/cctv/dahua/hfw3300c/dahua_hfw3300c_teardown_05-a1.jpg
So, if I had a bricked camera, here's what I'd do.
- Connect the serial cable to the pins on the internal serial connector.
- Run TFTP and set up the TFTP server root directory to the location of the upgrade files
- Power up the camera and see if it starts downloading files from the TFTP server.
- If it does, wait until it's complete, then reboot and see if it's better.
- If it doesn't, there's something missing from the procedure.
Here's the Hik version of the procedure, which is automatic:http://www.hikvisioneurope.com/portal/index.php?dir=Technical%20Materials/Special%20Tools/TFTP-Auto-Update/&file=Quick%20Guide%20-%20TFTP%20Automatic%20Update%20tool.pdf
and the Hik TFTP files, which may not work for Dahua - hard to say.http://www.hikvisioneurope.com/portal/index.php?dir=Technical%20Materials/Special%20Tools/TFTP-Auto-Update/
Sorry there's nothing more solid than this. This is one of the reasons I've quit buying Dahua.