If you have a Foscam FI9821W that failed after you attempted to update the firmware, then you've come to the right place. Mine died a few months back and I finally got around to fixing it, but discovered that the resources were scattered all over the internet in a variety of different languages. So I'll save you a few hours of head scratching and hopefully help you bring that camera back to life.
These cameras are now well out of warranty, and since you're not going to be able to get them repaired/replaced, there is no worry of violating your warranty. You've really got nothing to lose, and maybe you'll learn something along the way, so just follow the instructions below and don't get too intimidated.
FI9821W (These instructions and files are for Version 1 of the camera. While this process may work for V2 and others, they will use a different firmware so you'll have to find those yourself.)
USB to TTL Cable - If you already own something similar, it may work. It just needs a Ground, Transmit and Receive wire. If you're not an electronics geed, this one is only $6 on Amazon and comes with free prime shipping. https://smile.amazon.com/gp/product/B008AGDTA4/re...
(Optional) Some wire leads. I had some of breadboard leads laying around that worked perfectly. The terminals on the camera are tiny, and if you don't want to solder, a decent set of leads can actually just be pushed in and should work fine. Here are a ton more than you need on Amazon for $5: https://smile.amazon.com/Breadboard-Jumper-Wire-75...
Software: (Most of this is available in the attached FI9821W Recover.zip but I included external mirrors, just in case.)
The drivers for your USB to TTL adapter: http://leftbraintinkering.blogspot.com/2013/05/us... or https://www.dropbox.com/s/knu0gvzm3rwv20h/Profili...
Putty (Or the terminal emulator of your choice): https://the.earth.li/~sgtatham/putty/latest/x86/p... or https://www.dropbox.com/sh/lsrqv6j34gqe7gb/AAB5Igo...
The 126.96.36.199 firmware image: https://www.dropbox.com/s/crclzf36n45nzw8/flash_FI...
DNS and MAC Publisher: https://www.dropbox.com/s/40lmtqfn93q87mb/DDNS%26M...
The 188.8.131.52 app image (Optional): https://www.dropbox.com/s/8rwkm62s1nfxoxy/FI9821W_app_ver184.108.40.206.bin?dl=1
Foscam Web Components (Optional): https://www.dropbox.com/s/keeyk7r1fmx0zyz/FoscamWebComponents.zip?dl=1
Step 1: Crack Open the Camera
Unplug everything, turn it over and remove the two rubber feet, this works best with a knife. Cut through the two front stickers and remove all of the screws. The bottom simply lifts off.
Step 2: Attach Your Leads to the Camera
There are 4 holes in the motherboard, if you have the connector facing you and the plugs away, from left to right the terminals are: Cam Receive/TTL Transmit, Cam Transmit/TTL Receive, Ground and 3.3v which you will NOT use. If you're using the cable I recommended above, Green is Transmit, White is receive and Black is ground. I was able to use male/male breadboard jumper wires and plug them directly into the board with a little bending. But if you're using bare wires, you might need to solder them. They are tiny though, so I'd recommend making or buying some breadboard wires.
Step 3: Install the Serial Drivers
Before plugging in the USB cable, you'll need to install the Prolific Drivers. Just extract them, right click on ser2pl.inf and install. These will work on Windows 7 - Windows 10. Depending on your version of windows, you'll likely have to accept some permissions. Now when you plug in the USB device it should be detected. You can right click on This PC in explorer, select manage and go to Device Manager. You can expand on ports and you should see the Prolific USB to Serial Comm Port with a number after it. Note the COM number. If you see a yellow exclamation mark, just right click on the device, update driver, browse my computer, let me pick form a list, have disk, browse for the ser2pl.inf file you downloaded and click open.
Step 4: Talk to the Camera
Any terminal emulator software will work, but I like Putty. Just download it and run it, you don't have to install it but you can if you want. Choose connection type Serial, Speed set to 115000 and enter the COM# from your device manager you found the the previous step. (WARNING, when you camera powers on, it may try to spin which could result in it rolling off your desk, hitting the floor, tearing off your cable and destroying your camera. Be careful and make sure this doesn't happen by holding it in your hand or just placing it carefully on your work space.) Click open to start the connection and then plug in the Ethernet and finally the power cable (2nd WARNING to make sure your camera doesn't fall of your desk!). If all is connected correctly, you'll see text streaming across your screen. If not, go back and check all of your connections.
Step 5: Find an IP Address
Wait for the text to stop streaming, congratulations. You have a successful terminal connection to your device and everything else from here is just software. By default the camera has an address that you probably won't be able to reach. To work on it, you'll need to assign a static IP address. If you don't know what this is, we'll just keep it simple. Click Start > CMD and type in IPCONFIG at the prompt. You should see something like 192.168.0.49 as your IPv4 address. Note this down, you'll just need any free address on your network, that means that as long as the first the Octets (numbers) are the same, it will work. Try to ping something like 192.168.0.30 if it comes back with "Destination host unreachable' then you've got an acceptable address. Don't close the DOS box yet.
Step 6: Set the IP Address and See If You're Done
Set the address in your camera by typing "/etc/init.d/S80network e ifconfig eth0 192.168.0.30 netmask 255.255.255.0 broadcast 192.168.0.255" If it works, you can go back to the DOS box and press the up arrow key and it automatically type in ping 192.168.0.30 for you again, press enter and now you should see a reply. You can try going to 192.168.0.30:88 in your web browswer and you might see the camera. If so, you can just install the latest firmware via the last step and you're done. But I wasn't so lucky so if you're like me, continue on.
Step 7: Install the TFTPD Server on Your Computer
Choose whatever folder you're using to store the files (I just used my download folder) and set the server interface if you have more than one network card. This tiny server will host your files so that your camera can pull them.
Step 8: Boot the Camera Into Safe Mode
Power up the camera again being careful not to let it spin off your desk again and press ESC right away to stop it from trying to boot the main OS. Now you should be at a hilinux prompt.
printenv (Will show you all of your system environment variables)
setenv ipaddr 192.168.0.30 (Set's the camera's IP address)
setenv serverip 192.168.0.49 (Set's the IP address where your camera can find the TFTPD server)
ping 192.168.0.49 (Will attempt to ping your computer over the network and hopefully come back with 'host 192.168.0.49 is alive')
Step 9: Erase and Reflash the Camera
Now it's time for the real work.
protect off all (Disables memory protection erase 0x34000000 +0x1000000 (Watch your spacing, it has to be exactly the same to work. It should take a few seconds to erase all of the memory from 0x34 to 0x1)
tftp 0x34000000 flash_FI9821W_220.127.116.11_18.104.22.168.bin (This should start transferring the file from your computer to the camera. TFTP should show you progress as well.
reset (reboots your camera)
Step 10: Access the Camera Via Your Web Browser
The camera is going to grab a new address from DHCP so you can use the ifconfig command to see what that address is, or you can use the Foscam IP CAM tool to scan for it. Once you find the new address type it into your web browser http://192.168.0.51:88 (88 is the web port for these cameras) Now you should see the standard interface. The username is admin and there is no password. Click Login and you should see the Device information screen.
Step 11: Reset the DDNS and MAC
Now you need to reset the DDNS and Mac to get it all back to normal. Run the DDNS&MAC Publisher.exe file. Look at the bottom cover of your camera for this information. Enter in your DDNS username, something like bk5837 and enter the same for your DDNS password. Enter in your MAC as numbers and letters only, something like 00626E4751BC. Then enter in your camera's IP address and port 88. Press Set DDNS first, and it should say 'Process OK' then Set MAC and get another 'Process OK.' Refresh your web browser and you should see the right camera ID.
Step 12: Retry the 14 Firmware Update
At this point everything should be working, but firmware 14 is the last one for this camera and it does have some fixes so I'd recommend you do the update. Just go to System > Choose file > Select the FI9821W_app_ver22.214.171.124.14.bin file and click System Upgrade. Wait for the reboot and you should be all set. You can assign a static IP address so you can keep track of the camera now.
Step 13: Watch Your Camera
Bonus, if you can't see the camera in Chrome, just install Foscam Web Components and IE Tab in Chrome. Then you can pull of the camera's page in Chrome via the IE Tab extension and your camera should work. Also, IP Cam Viewer for Android and IOS gives you full PTZ control of the camera or you can use the Foscam app.