I am trying to revert TL-WA901ND v5 back to factory firmware in openwrt. It it giving me error check error. I found that I need to remove 32byte & have it in .trx. I tried that but it still doesn't work still getting the same error. The firmware I got was from TP link.
I was originally trying to setup client bridge from wifi, but failed thus I want to revert back.
Please help. Thanks.
ok 
I have the file to revert back
but this file only work for V5 version
be careful
you should have WinSCP enter to the access point to /tmp
and put the file tplink.bin
and open ssh and type this
mtd -r write /tmp/tplink.bin firmware
the link
https://mega.nz/#!4t9H2b6Q!iV7HULQaqLMIdu7xaEgnm_ASNwzRNUsLsNrHqoynXg8