WIFI stopped working

[Morq]

Aight so I'm using wifi on my l820 quite often and so far it worked fine - until some time ago when it started acting dodgy - at times it connected, sometimes it didnt.
Since yesterday it seems I cannot connect to any wifi at all, I always get error message saying that "Your phone couldn't connect to Wi-Fi network xx because there was no response from the network". The thing is everything else works and I never had any issues with connecting anything to it before (its my own network i set up in my home).

Turning wifi on/off doesnt work, reseting phone did not help either. So far tried 3 networks that worked before with same result. Anyone has any idea what can cause this?

 

[Narr]

I've been having this since Monday, I reset my phone on Saturday and had no trouble connecting to WiFi over the weekend and downloading the apps and settings once again. I tried to connect to Virgin WiFi on the Tube Monday and I got the same error; I managed to get around it (temporarily) by switching on Flight Mode, turning off and then trying WiFi again. It works for a while and then will stop making new connections.

 

[Morq]

My wifi router had "channel" option set to "Auto". Changing it to anything and then back to "Auto" fixed the issue (at least for my home network).
This is ******ed to say at least.

 

[Morq]

And.. after a day wifi stopped working again.
Stopped to connect on lumia820 and 710. Works perfectly on ancient ipod3g which wasnt touched for weeks.