I've had this 3DS since the day it came out (March 2011), and I've never encountered this problem before.
I've been able to connect it to all three of the routers that we've used since 2011 (two crashed, and this third one's doing fine), and I've never had any problems.
However, back in June, the wireless on the 3DS started acting up.
When I moved back home from college in May, I deleted my dorm's wifi settings and put back my home wifi settings. I've always been connected fine, and I was connected for about two weeks after I got home.
Suddenly, in June, everything stopped working. I couldn't figure out how to get the internet back (I've deleted and redone the settings several times, and I've turned the router on and off again, as well as turning the system on and off again). Sometimes I'll connect to the internet, but I'll have 1.5 hours of internet time on a good day, and less than five minutes on a bad day. Most days I just have no internet at all.
When I search for available connections, the three bars saying "Yeah, this signal's strong!" show up, but the name of my home router doesn't show up at all. It's just blank, and I can't connect to it, even with the proper security code.
If I reset the router, I can connect to it, and it shows up as my home wifi name on the system. The security code goes through, the connection test is successful, and they tell me to go on my merry way.
Then about five minutes later, the internet will drop off and I won't be able to get it back, no matter how many times I reset the router.
This just started happening in June. I've never had this problem before, and it's really starting to bug me. I keep wanting to go visit peoples' towns in Animal Crossing, or have them visit mine, and I simply can't sustain an internet connection long enough to do so. It always says "No access point in range," when there is an access point in range.
My phone, my iPad, and my computer all connect flawlessly to this particular router, as do the other phones/computers in the house. I am literally at my wit's end with this.
Is there anything else I can try?