Một giải pháp của một Anh Tây và nhiều người test thành công NGuyên văn: Wifi problem after unlock/default efs/imei? Solution here To all that are facing problems using wifi after any procedure, (unlock, repair imei or reset efs defaults) and your wifi is not fully turn it on.. or it justcant connect to any network... Tested in Note3 sm-n900 and S4 i337(m).. 1. Root your device with any method you like... (cfroot, kingo, etc) 2. Install root explorer 3.0 (or any newer version available) 3. Open root explorer and locate EFS folder (dont forget to mount as R/W) and Delete it (it maybe will say error, just try again) you know it is done when you press power button to turn off (it will power off without select power off option)