Restoring to original firmware
The router can be restored back to original firmware by manually flashing original firmware.
- visit TP-LINK download website
- find your router (TL-WR740N_V4)
- select version of your router's hardware from dropdown meni
- download .zip of latest firmware of your router
- prepare firmware
- upload firmware on router
- connect to the router through ssh
- change directory to /tmp
- flash firmware
Once you download right firmware zip and unziped,
you may see word "boot" in firmware binary name (wr740nv4_en_3_17_0_up_boot(150105).bin).
This have bootloader and we need to remove it:
cd /dir/with/boot-firmware/ cp wr740nv4_en_3_17_0_up_boot(150105).bin firmware-boot.bin dd if=firmware-boot.bin of=firmware.bin skip=257 bs=512
if you have modified firmware (from boot version) or if there is just .zip, or if you can't do:
cd /tmp wget http://link.to/firmware.bin
we need to download to computer and upload it in router
for GNU/Linux do:
scp firmware.bin root@10.<routerIP>:/tmp/fw.bin
this will ask you for router password from nodewatcher
At this point you are connected on router via ssh. Now move to /tmp directory and flash firmware it:
cd /tmp mtd -r write fw.bin firmware
Restoring default setting
Restoring settings that came with the firmware image:
- Turn off the router.
- Find the small QSS button. Turn on the router, when SYS light turns on, press QSS button for 3 seconds, so SYS light starts blinking rapidly.
- Give your computer a static ip 192.168.1.155 with mask 255.255.255.0 (http://www.howtogeek.com/howto/19249/how-to-assign-a-static-ip-address-in-xp-vista-or-windows-7/).
- Set up a telnet connection (pomoč: http://www.youtube.com/watch?v=uE6G2n5AyRw#t=0m17):
- Windows: star program Putty, choose "Connection type" telnet, enter IP: 192.168.1.1 in click Open.
- Mac OS X and Linux: telnet 192.168.1.1 command in terminal.
- run the following commands
firstboot sync reboot
- Turn off the router and turn it back on. You are on firmware default settings.
Restoring bricked router
The router can be connected to the computer serial cable using a serial cable.
Connection can be established with the following settings on GNU/Linux or OS X:
cu --parity=none -s 115200 -l /dev/(your serial device)
In case of issue, try
sudo chmod 777 /dev/(your serial device)
Before soldering try http://bkil.blogspot.hr/2014/12/tftp-secret-of-tl-wr740n-uncovered.html
The router can be upgraded/fixed with a TFTP method, although its use should be avoided if possible. A working serial cable is required.
- prepare your tftp tools
- get firmware from nodewatcher
- connect to the serial interface
- expect Autobooting in 1 seconds write tpl within a second
- set ip of the router and computer (has to have a static IP)
setenv ipaddr 192.168.1.1 setenv serverip 192.168.1.100
start tftp server on your computer and include the desired firmware in its path
run the following commands
ar7240> tftpboot 0x80000000 yourRightTPlinkFirmware.bin ar7240> erase 0x9f020000 +0x3c0000 ar7240> cp.b 0x80000000 0x9f020000 0x3c0000 ar7240> bootm 0x9f020000
router will reboot and start with the new firmware