Hi I had my wifi working fine before until I burnt the new latest debian os , now with this new os I get board overheating and wifi displaying existing network but not able to connect to any of them??? How can I resolve this??? Thanks
You can try to install Wicd after the installation reboot your BPI and it should work fine 
If you need help with the installation you can ask me but there is a good instructions from the Ubuntusers-Wiki
Good luck 
greetings, root_Padi
Make cooling radiators, temperature is not more than 50-60% ))) 
I did similar things to mine. I also put a 5v fan in the top to cool the board and removed the sides to keep it cooler.