How to fix Wi-Fi on restored iPhone?

I jailbroke my iPhone 4s with evasi0n software about a month ago, for various reasons, and it was working fine for the first few days, but then it started refusing to connect to any Wi-Fi networks, and eventually didn't find anything at all. I started by resetting the network connections and the general phone settings, and when that didn't work I restored it fully. When that didn't work I did it again, and a third time. It still doesn't work and I was wondering if you could tell me if there was anything I could do, and if I could take it to an apple store or they would arrest me or something.

Well the only solution to this tends to be to go to Settings - restore - restore internet settings.

If it's not a untethered jailbreak you have to use the correct ispw to boot up your phone as well.