@Tesla59 

1. Download stock firmware from tplink website for your device and unpack it. For a example next link   https://www.tp-link.com/en/support/download/tl-wr840n/v2/#Firmware
2. Perform command: dd if=orig.bin of=tplink.bin skip=257 bs=512 to create firmware for tftp
3. Use tftp mode to flash tp_recovery.bin
4. or watch this video to creat stripped firmware https://www.youtube.com/watch?v=HNg1CZGZ9N4&list=WL&index=34&t=6s

@Tesla59 

Hello i also have similar model

TL-WR840N<W> BR v:4.0   ISP customized firmware support 

We bought them for our ISP and installed the customized bin, everytime we reset the router it reboots with our ISP configuration, but now we have a problem

we need to change the customized data so we have created a new firmware.bin customized with new WIFI etc.. credentials..

we tried loading into the routers using the .bat files on the manuals  it finishes the process after 5 minutes. but after reseting the routers they allways come with initial customized data from our ISP. and not with the new backup data we tried loading..

so i tried to flash the original firmware via tftpd after loading sucess all lights are now flashing like a christmas tree.

so i kindly request for the correct  tp_recovery.bin  for the TP-LINK TL-WR840N<W> BR V:4.0

@PortalNET 

Hi there

Which customised firmware did you use for your router?!!! OpenWRT?!!!  Use the latest version 19.07.2

if You want to return to TP-Link Original firmware,You should be aware that Original firmware contains with uboot (TL-WR840Nv4_BR_WISP_0.9.1_3.16_up_boot[180920-rel55953].bin) and needs to be stripped

You can use this command to make one

dd if="TL-WR840Nv4_oficial-da-tp-link.bin" of="tlwr840n-v4-stock.bin" bs=512 skip=1

Returning to Factory Firmware
To return to the factory version, it is necessary to modify the official firmware so that its header is deleted.

Download the official firmware from the TP-link page (taking care to download it in the right language, some models are country specific so you need to download the corresponding one).

     Now use the command below:

dd if = "TL-WR840Nv4_oficial-da-tp-link.bin" of = "tlwr840n-v4-stock.bin" bs = 512 skip = 1

The file tlwr840n-v4-stock.bin will be created, using the command above.
 Repeat the firmware burning process via the TFTP server, renaming the file tlwr840n-v4-stock.bin to tp_recovery.bin.
If the original firmware is burned without the above procedure, the device will end up being bricked.

Let me know

@PortalNET 

http://www.mediafire.com/folder/zijo3fin2pbko/TL-WR840N_W_V4

I just stripped the original firmware with this command 

dd if="TL-WR840Nv4_oficial-da-tp-link.bin" of="tlwr840n-v4-stock.bin" bs=512 skip=1

let me know when you're done successfully

I work on the web of best crossbow broadheads for deer & i have a office work which are devided into different peoples but our room is same ......If I use this device to spread connection to others then how,s the experience ? & also tell me about its frequency....

@David.1983 hello sir

would you pls stripping this firmware for me ? I already installed ur modified firmware but i need it in english version

http://www.mediafire.com/file/l4hgh02d2am9b53/TL-WR840N(EU)_V4_170421.zip/file

@Benghazinho 

Did you flash BR Version?!!! Did it work? if your answer is YES just let me know