No Wifi after iPhone 3.1 upgrade

I have the same exact problem the ipod connect for about a year then i switched to 4.0 and it worked for a while after that too, then i camped outside one night and when i came in it would just say no wifi

It is a hardware physical defect with the soldering process during the assembly of the logic board as far as I can tell. I noticed when I upgraded to 3.13 my phone started getting really hot when it was on WiFi, it never did that on 3.1.2. Then after about a week into the upgrade it quit working completely.

My theory is that the chip over heats due to bad software temperature instructions and then gets too hot and because the WiFi chip is glued on in the initial production process the overheating causes the connections to become weak on the Marvell 88W8686 chip and they eventually give out. It is possible the glue melts underneath the chip connections and the WiFi chip becomes disconnected from the PCB and stops working. At first mine was not showing the WiFi icon even though it was connected, then the connections got worse day by day, then it totally died out. This would be consistent with glue gradually melting under the chip when overheating when I was using it on WiFi. I really don't know crap about electronics but this seems like a logical cause for the chip connection failure which is definitely is because I was able to fix the connection on mine in about ten minutes with a soldering iron. So it is positively the WiFi chip connection that is the problem. Here is how I did it...

http://www.snackyserve.com/iphone3g_wififixed/index.html

How can so many people have this problem and yet Apple doesn't feel the need to get it fixed properly? I've tried all the 'solutions' they suggested on their website, without success. My iphone 3GS can't find any wifi networks, anywhere although it's worked fine for years. Even if I type in my network name, it won't find it. I have 3.1.3. I wonder though if the following info might tie in with other folk having the same problem... . I was abroad last week, turned data roaming off and my iphone picked up wifi without problem. As soon as I returned home to the UK my wifi had gone. I've restored, reset, rebooted, switched everything off, contacted my ISP... in short, done everything that everyone has recommended. Zilch. Come on Apple, please get this sorted asap.

Try resetting your router it worked for me. Turn router off press the reset button then turn back on. Pass it on.

Thanks for the suggestion. Had already tried that but tried it again, no luck. The phone's not finding any wifi anywhere, not just at home.