Can not flash OpenWrt to router tp-link mr3420 v5

I have a tp-link mr3420 v5
I am trying to flash openwrt via tftp as mentioned in this link

but there is no response at all..
what to do?

@teken, welcome to the community!

  • Can you provide more details?
  • For example, is there any activity on the TFTP server?

thanks for replay,
there is no activity on TFTP server at all, I sniffed the network via wireshark and no network traffic
I am tryed to flash to another router kind at the same TFTP server and succssed!!