Milan Kragujević

Milan Kragujević

@milankragujevic on Mastodon

July 15th, 2018 / 1 minute read

How to restore TP-Link MR-3420 V5 to factory firmware

If you’ve upgraded your TP-Link MR-3420 V5 to OpenWRT firmware, you might find that you can no longer flash back the original system firmware. Trying to flash the official firmware from TP-Link results in a “soft brick” (all lights light up and then WAN lights up orange and the router reboots).

If you already have a soft-bricked router, re-flash OpenWRT using a TFTP server, like shown in my tutorial here.

Log in to OpenWRT with SSH (, user root, password empty or whatever you set) and execute the following commands:

wget -O code.bin
dd if=code.bin of=tplink.bin skip=257 bs=512
mtd -e firmware -r write /tmp/tplink.bin firmware

Your router will reboot and will be flashed with factory firmware.

In the SSH console your log should look something like this:

[email protected]:/tmp# wget -O code.
Downloading ''
Connecting to
Writing to 'code.bin'
code.bin             100% |*******************************|  7936k  0:00:00 ETA
Download completed (8126976 bytes)
[email protected]:/tmp# dd if=code.bin of=tplink.bin skip=257 bs=512
15616+0 records in
15616+0 records out
[email protected]:/tmp# mtd -e firmware -r write /tmp/tplink.bin firmware
Unlocking firmware ...
Erasing firmware ...

Writing from /tmp/tplink.bin to firmware ...  [w]

Rebooting ...

After the router reboots, it is very important to reset it to factory default settings, or else you might have problems after rebooting it.

Press and hold the WPS/Reset button until the router reboots, then open and follow the quick setup wizard.

If you encounter any problems, please comment below and I’ll try to help you.