Please help me! RB711-5Hn-u.Fl does not work the LAN port after a storm. On a radio channel to a point I am connected without problems. Tried to reset by closing the contacts on the Board - did not help. The LAN never started. green indicator blinks only at the beginning, orange does not light up at all. Made a video, can you tell me what to do with it? Throw it in the trash?
https://youtu.be/MDBDVJwX9MU
What was connected on that ethernet port during the storm?
Did you try to netinstall and see if it works?
Was connected switch, but he remained alive. Netinstall does not see an access point since with it in General there is no physical communication - Windows writes: “the network cable is not connected”. The cable is whole, the connector is whole, the power supply is whole.
On how many I understood, it is necessary to solder the processor AR7241-AH1A? In some sources it is written that it helps for LAN recovery after a thunderstorm.
Take a look here on how we perform netinstall on a device https://wiki.mikrotik.com/wiki/Manual:Netinstall
I’m doing it this way. Perhaps you misunderstood me. The computer does not physically understand that there is a device at the other end of the cable. Are you sure that with this connection netinstall will see the access point?

It’s damaged, probably over-voltage or static on cable… usually rx path is dead and so it’s ready for trash bin…
As there is no external ethernet phy, you would have to replace the CPU chip to fix it…
I agree with you r00t. However it worths trying to netinstall his device…
I found the processors on Aliexpress:
https://s.click.aliexpress.com/e/3h1zfSyY
Tell me it will fit? Costs only $3
How can you be sure its the processor???
r00t is right, LAN is controlled directly by CPU. There is a D1001 suppressor assembly between the connector and the processor. Maybe she’s the problem.
Since you are sure let us know if it works after the replacement…
I’m not sure on this and asking for your help on this forum. Maybe someone faced with a similar problem. I don’t think thunderstorms are only in Russia ) maybe someone already perephial processors? Or restored LAN differently-write here, please, I with pleasure will read your comments
yes, I have replaced some chips on RBs before, usually it fixed the issue unless there was some other serious damage to board tracks. I can say that there are no other “gotchas” like on some other boards, if you replace CPU on RB711, it should work again. But you need hot air rework station, tools and flux/solder paste and some experience to do it properly. If you know what you are doing, it’s 15 minutes of work to fix it…
Yes, the tracks are intact, the processor was most likely put out of action by a slight static voltage. Soldering station and soldering experience I have, but no processor. I will order it on Aliexpress at the link I sent above. It may take about a month, but if I succeed - I will write about it.If still someone has experience of restoration of LAN-write, please.