Why is the wifi router not working?

Question

network hardware

Hello.
There was a following problem.
There is a linksys cisco router.
Everything used to work fine, but at some point it started to act up.
The symptoms are as follows:
Normal Internet is fine.
WIFI - without turning on protection - everything is fine.
WIFI when you turn on WPA protection (WPA2, etc. at different frequencies) does not work. Tried from laptop and phone. The router itself sees, tries to connect and that's it. Constantly trying to authenticate on the phone when connected, it says that the signal is weak, but when you stop trying to connect, the signal is excellent. It is not possible to log into the router from the laptop, although it says that it has connected, albeit without Internet access. What to do?

Answer 1

reflash.

Answer 2

Look at the logs.