Hi there
I installed Openwrt on my tp link tl-wr840n v5 router and for some reason wanted to recover original firmware
when I installed the original fr I bricked it
I used tftp and could upload original frimware

Connection received from 192.168.0.2 on port 1890 [03/06 15:54:59.704]
Read request for file <tp_recovery.bin>. Mode octet [03/06 15:54:59.704]
Using local port 60724 [03/06 15:54:59.704]
<tp_recovery.bin>: sent 7938 blks, 4063744 bytes in 7 s. 0 blk resent [03/06 15:55:06.261]
 

I couldn't find any solution yet