SXT R R11e-LTE6 powered but not reachable and not connected

Hi guys,

I have a problem with this router, the lte led was off and the admin panel was unreachable, I made the “Loading the backup RouterBOOT loader” found at https://wiki.mikrotik.com/wiki/Manual:Reset.
after this I could reach the admin panel but I couldn’t connect to the internet. I tried the simcard in another router and it works fine.
Now, after a while, I can’t reach the admin panel again. I tried the same procedure but nothing. I also tried to keep pressed the reset button, waiting for the led to flash as describer in the “Resetting the RouterOS configuration” but no led started flashing after one minute.
I am hopeless at the moment, would you have any suggestion?

Luca