TP-Link Archer C6U bricked

Dear Everyone,

Yesterday i bought a TP-Link Archer C6U and then installed the suggested image.
(https://openwrt.org/toh/hwdata/tp-link/tp-link_archer_c6u_v1_eu)
https://downloads.openwrt.org/releases/21.02.2/targets/ramips/mt7621/openwrt-21.02.2-ramips-mt7621-tplink_archer-c6u-v1-squashfs-factory.bin

I used the web gui for this, then the router reboot and bricked.

If I'll try to attach the pc to lan1 the lan1 is go down. If i use switch it stay up but i can't get ftfp recovery method. Someone can suggest me wasy to recover my router?

Thanks,
László

this is usually because of a firewall on the host running the tftp.

Yes usually but unfortunately its not the problem now. :frowning: Firewall turned off.
I watch the packets with wireshark and the router don't send anything.
But on intresting info:
If i don't press the reset button while starting the LAN1 interface auto turned off and no link on it.

if there's no traffic coming from the device, the next step would be serial console.

Can you suggest me a device for that? I don't have USB TTL now and there is so much option.