I was using Facebook then suddenly the phone switched off even though the battery was almost full, i put it on charge. It charged & switched on i opened Facebook again and the phone searched for wifi but it couldn't detect anything it was only showing the name of the data provider & hidden wlan (i checked with my e71 at that time & it was showing 3 networks). then i switched it off after that i switched it on again but it started restarting on its own & wouldn't switch on so i gave it to Nokia care & they changed the battery. Since then no wifi.