Tp-Link WR840 - Bricked

Installing and Using OpenWrt
1

Hi.

I bricked my router today, after a wrong flash (don´t know what happened).
Does anyone have the serial scheme and instructions for this router?

Thanks.
Juliano

2

Try TFTP recovery:

3

I also have same router TL-WR840N V4 and it got bricked and I followed instructions to recover and did the following,

  1. downloaded the dd application and "firmware upgrade" (for TL-WR840N V4 from TP-Link website)
  2. used command to skip header from firmware upgrade { dd if=original.bin of=tp_recovery.bin bs=512 skip=1}
  3. downloaded tftp64 and uploaded tp_recovery.bin to my router and it worked.
    Now WLAN MAC address has become FF:FF:FF:FF:FF:FF which is causing trouble as I try to connect my phone to this router.
    my question is can I just change my WLAN MAC Address of my router to the original as printed on the ticket.
4

You want to set the Mac address on the router having the stock firmware ? Try this: https://www.tp-link.com/us/support/faq/68/

5

I want to change the WiFi MAC Address of my router and there is no option in the configuration page to change the WLAN MAC Address

6

check the uboot-envtools package

and https://openwrt.org/docs/techref/bootloader/uboot.config

7

any simple solution? like writing MAC address in firmware bin file (editing via hex editor etc) then uploading to router via tftp

8

that is the simple solution, assuming it's actually set wrong (or unset) in the uboot environment.

9

Unfortunately, I am not that much familiar with the commands used in u-boot environment that's why asking for a simpler solution like editing bin file before uploading to router

10

trust me, editing a bin sure ain't easier than using a couple of commands on the cli prompt.

11

OK, I am going to try, by the way, thank you so much for your precious time. I hope I will always get help from experts like you.

12

Can you please guide me step by step (like downloading relevant tools/utilities, accessing u-boot and also download link as I am unable to find, by the way I am using Windows 10)

13

that's what's in

15

after spending hours and trying to understand what the article says, I uploaded latest tftp recovery.bin (openWrt of course) to my router, searched for updates (http://192.168.1.1/cgi-bin/luci/admin/system/opkg) and finally installed uboot-envtools and fwtool.
accesed router's root in putty and tried to run commands as article suggests, but unfortunately no "/etc/fw_env.config" found
error: can not parse config file /etc/fw_env.config
when I try to run
"opkg install uboot-envtools" command, it says its installed and up to date
when try to run
"vi /etc/fw_env.config" command, putty gets stuck on
root@OpenWrt:~# vi /etc/fw_env.config

~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~

  • /etc/fw_env.config 1/1 100%
    and I have to close putty after a long wait
16

it's an editor, you can wait forever for it to terminate :slight_smile:

next time, press < esc > : q Enter(key)

https://www.cs.drexel.edu/~kschmidt/Ref/vi_reference.html

you need to populate the fw_env.config with the configuration matching your device.

https://elinux.org/U-boot_environment_variables_in_linux

2 Likes
17

Or

:q!

That's everything you need to know about vi or vim.

18

:rofl: :joy: :rofl:

You made my day

19 
root@OpenWrt:~# opkg install uboot-envtools
Package uboot-envtools (2018.03-3.1) installed in root is up to date.

root@OpenWrt:~# opkg install fwtool
Package fwtool (2) installed in root is up to date.

root@OpenWrt:~# cat /proc/mtd
dev:    size   erasesize  name
mtd0: 00020000 00010000 "boot"
mtd1: 007a0000 00010000 "firmware"
mtd2: 0017f777 00010000 "kernel"
mtd3: 00620888 00010000 "rootfs"
mtd4: 003d0000 00010000 "rootfs_data"
mtd5: 00010000 00010000 "config"
mtd6: 00030000 00010000 "factory"
root@OpenWrt:~#

**No "uboot"**
**No "uboot_env"**
**what should I do?**