How to Unbrick TP-Link TL-WR740N WiFi Router Easily

A new version of the popular OpenWRT firmware for various WiFi devices has been released recently. This is why I thought of upgrading my TP-Link TL-WR740N router to the latest OpenWRT version (Chaos Calmer 15.05-rc2). But unfortunately doing so actually bricked my router. When a WiFi router is bricked, the only possible way to unbrick is to use a serial cable and solder it to some points on the router’s circuit board. But lucky for me, there is also a very easy method to unbrick the TL-WR740N router.

Here is how you can unbrick your TL-WR740N router in a few seconds without needing any serial or JTAG cable:

  1. Power off the WiFi router.
  2. Download the latest firmware for the router from the TP-Link website.
  3. Extract the firmware BIN file from the download ZIP archive. Rename the BIN file to wr740v4_tp_recovery.bin.Debrick TPLink WiFI Router
  4. Download and install TFTP server. It will ask for Firewall permissions which you should grant for it to work.
  5. Open Network settings in Windows control panel. Change the network adapter settings (the network adapter that is wired to your WiFi router) and set the static IP address to 192.168.0.66, subnet mask to 255.255.255.0 and default gateway to 192.168.0.1. Save the settings.Debrick TPLink WiFI Router
  6. Open TFTP server  and change the working directory to where the wr740v4_tp_recovery.bin is copied in step 3 above. Change the server interface to 192.168.0.66.Debrick TPLink WiFI Router
  7. Press the reset button (using a paper-clip or pin) of the router and power it on. Do not release the reset button for 4-5 seconds after powering it on. As soon as you release the button, TFTP server shall flash the firmware and start the router.
  8. That’s it. Now you have a unbricked working WiFi router without actually needing any serial cables.

This method works for many models of the TP-Link WiFi routers. The original credit of this hidden unbricking method goes to bkil (http://bkil.blogspot.com/2014/12/hidden-tftp-of-tp-link-routers.html).

12 thoughts on “How to Unbrick TP-Link TL-WR740N WiFi Router Easily

  1. Hi Trisha I have a TP-LINK TL-SG3424 and it is bricked. I have setup the tftp server and it downloads the firmware file. When I reboot the Switch it says that the format is unrecognized. The switch then connects to the tftp server again and re-downloads the file. The filename that it looks for is uImage.img. Have you got any thoughts on what I should try next?

    1. make sure that you are using the firmware file for the correct version of the device. uImage.img is compressed kernel and root filesystem image. The bootloader is asking for uImage so it can boot into the kernel and then the kernel will take over.

  2. Hi Trish,
    When I reboot/reset the router I do not see a connection request from the router in the log window. What could I have done wrong?

    1. If you have taken all the steps as described then perhaps there is hardware problem. Try using a different LAN cable or different PC. If all else fails, then perhaps bootloader is corrupt or device has other problems.

  3. doesnt work for me. i followed all the steps. My tp link wr740n router is dead and displays power LED and LAN4 led only. no other activity.

    1. In a bricked router LED’s do not light up. Your router may have hardware problem – most probably one or more capacitors have gone bad and are not able to supply stable voltage to the other components.

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