Why does wifi drop out when connected to any Ethernet port on a Kinetic Giga router?

Question

WiFi

Hey!
I have routers of this brand at work, at home and with relatives.
The latter had problems since the summer.
We stick the cable from the computer into any port of the router and wifi immediately disappears.
On the router itself, the wireless diode starts blinking randomly.
Previously, these problems did not arise. The router was configured 3 years ago.
Reboots do not help, reset too.
I also noticed that with a computer via a cable with a router it has a long network initialization.

Answer 1

since summer

Possibly the aftermath of a thunderstorm?
Try another power supply, this is the very first thing to do.
Open the router, see if any capacitors are swollen.
Feel the processor to see if it's overheating. You may need to add a fan for cooling.
Well, if the above measures did not help in any way, then 99% that you yourself will not be able to fix this problem, then only give it to a repair specialist. Or a trash can.

Answer 2

This happens if the router "arrived" after a thunderstorm. There are two options, in the first case, the LAN port may burn out, then there will be no link at all. And the second option - the LAN port closes, it turns out like a loop, and when the cable is connected, chaotic data transfer begins. And since wifi is in a bridge with lan, this interferes with the work of wifi itself. You can try to separate lan and wifi networks so that they do not interfere with each other. Or programmatically disable the faulty lan port (if there is one)
If you want details, you can read for example https://habr.com/en/post/303062/