Internet not working via cable on Macbook?

Question

macOS

You turn on the MacBook, the Internet through the cable works fine. Then after a while it cuts down and connects to WiFi and the Internet works fine through it. In the network settings, in the status it says: "The cable is disconnected." I tried to connect to another router and connect with a different cable, the story repeats itself. How to solve the problem? And even after a reboot, the Internet through the cable also works for a while, then it cuts out again.

Answer 1

I would recommend resetting the beech to factory settings, and then boot into recovery mode and check the network there. If it falls off there, the conclusion is that iron is to blame.
Then there are two options:
Network via usb (may be slow, depending on the version of usb), or replacing the motherboard of the macbook (depending on the model, it can be from 5 thousand to 100 thousand)
If the network will work without problems in recovery mode , this is a reason to reinstall the OS.