I have a iPhone 3G, it fell down.. I changed the glass and back cover. Now the WiFi is not working..
I tried all firmware right from 3.1.2 till 4.2.1.
I tried some tricks on the internet.. like keeping it in the freezer for 10 minutes.. none worked. I used the iphone Configuration Utility by Apple. And it see's the WiFi hardware..
Please suggest as what could be done to fix it.. some told to re-heat the WiFi area on the board.

Please suggest anything that you may know on this issue.

Thanks all.