Region : Romania

Model : TL-WR741ND

Hardware Version : V4

Firmware Version :

ISP : RDS

Hello all! I'm new on this forum, after a lot of research I decided to sign up and post here my issu.

I have a TL-WR741ND v4 router and yesterday after upgrading the firmvare, downloaded from the official website, through the WEB interface, it finished and after it rebooted the power on (first) led was lightning (continuosly) and the others are blinking every 1-2 seconds.
I tried to reset it, 30-30-30 but after I push the reset button for like 3-4 seconds the last led (the one with the locked sign) lights up and keeps lightning (continuosly) and the others stop blinking, after I plug back the power cord happens the same.
Tried to access it via the WEB interface and it's not working, tried via the LAN cable which was connected to my PC, tried to telnet it but no luck. Everything I would try to do when I power it all the lights/leds blink, except the power sign/led.
What can I do in this situation, did anyone have this problem til now?

Thank you in advance.