Unbrick and restore firmware TP Link WR841N V8 to stock firmware

Step 1: Download stock firmware from TPLINK website, renamed file 841n.bin
Step 2. Copy 841n.bin to Linux OS (Ubuntu or Fedora). 
Using following command to remove boot part. After this command, we have file named firmware.bin

dd if=841n.bin of=firmware.bin skip=257 bs=512

Step 3: . Install TFTPD Server (TFTPUtil_GUI_Version_1.4.5_Binary_Installer.exe) from https://sourceforge.net/projects/tftputil/files/TFTPUtil/TFTPUtil%20Version%201.4.5/

Copy firmware.bin to TFTPUtil folder (C:\Program Files\TFTPUtil\)
Turn of firewall of Windows OS.
Set static IP of Windows : 192.168.1.2
Subnet mask: 255.255.255.0
Turn ON router.
Plug Network Cable to LAN port of Router (dont connect to WAN Port).
Config TFTPUtil to using IP address : 192.168.1.2

Step 4: Connect Serial USB adapter to Router, and Windows PC. We need connect TX, RX, GND pin and plug power cord to Router (dont connect VCC to Router pin ).

Step 5: Using following parameter to connect Serial 

Baund Rate : 115200
Data bit : 8
Stop bit : 1
Parity: None
Flow control: None

Step 6: When Screen display "Autobooting in 1 seconds". Press tpl to enable command line interface of Router.

Set ip for Router and TFTP Server using following command:
setenv ipaddr 192.168.1.10
setenv serverip 192.168.1.2

Step7:

Load firmware to RAM from address 0x81000000 (you can check by printenv command) using command
tftpboot 0x81000000 firmware.bin

Erase flash from 0x9f020000 address using command:

erase 0x9f020000 +0x3c0000

where 0x3c0000 is the size of firmware.bin (0x3c0000 byte ) in hexadecimal

Copy firmware from RAM to flash using command :

cp.b 0x81000000 0x9f020000 0x3c0000

where 0x9f020000 is address in flash which router read to boot firmware.

Enter following command to boot firmware and Voila, router is boot complete to firmware stock.

bootm 0x9f020000


Nhân đây mình cũng nhận sửa lại các router TPLINK mà các bạn up nhầm, hoặc lỗi firmware. Liên hệ với mình nhé.