Why the router may not work stably?

Question

WiFi

Good afternoon,
For a month now there has been a problem and it is not completely illogical and incomprehensible.
In general, there is a TP-LINK router, it worked perfectly, but for a month now the network began to disappear through the LAN periodically 2-3 times per hour. And then the same problem with wifi began.
The router was 2-3 years old. Changed to TP-LINK archer c2. Absolutely the same problem, but only with wifi. Through 2 walls no longer catches. The speed is cut very strongly. Through 1 wall at 80mb/s.
I thought the problem was in the channels and so on. But no .. I found a very old dlink dir-320 and .. It works just perfect, it catches everything gorgeous, the Internet is stable, the speed through 3 walls is cut to 60 mb / s.
I put TP-LINK in repeater mode (WPS), so it also started to catch chic, but the Internet became unstable again (as if dlink 320 could not withstand the load) and started to fall even through LAN.
The situation is extremely strange, has anyone come across this? Or similar? Why, in theory, could this be?

Answer 1

Scan Wi-Fi for neighbor networks. Determine busy channels. Find a free channel. Switch to a free channel.

Answer 2

I had a similar situation on an ASUS router. I found out that the chip inside the router was overheating, I stuck a radiator on it, everything worked. There must have been some sort of marriage. But then I switched to mikrotik. 5 years flight is normal. Covered in dust but working for glory.

Answer 3

Do not forget about interference from household and industrial equipment used in neighboring rooms, which is also often the cause of failures in Wi-Fi networks.
All these factors affect the operation of Wi-Fi, often leading to unexpected situations when there is a signal, and the network is almost non-existent.
conduct a radio survey (there are simple free programs)
https://solaris-it.ru/site-survey.html
check the general settings
https://solaris-it.ru/nastrojka-routera.html