Samsung S4 mobile phone can't connect to WIFI.

If the wireless switch of Samsung mobile phone can't be turned on, this situation may be caused by system or hardware failure. Suggestion: Back up mobile phone data (phone book, SMS, multimedia files, etc. ) and restore the factory settings (enter Settings-Reset-Restore Factory Settings). If the wireless switch can be turned on, it is recommended to do the following: 1. Switch the phone and wireless device again. 2. It is suggested to forget the network and reconnect. Operation: Settings -WLAN Settings-Click on the name of the network to be deleted and don't let it go-Forget/delete the network. 3. Try to replace the static IP. 4. Whether it is too far away from the wireless router, which affects the received signal. 5. If conditions permit, will this happen when switching to another router or trying to connect wirelessly? 6. Back up mobile phone data (phone book, SMS, multimedia files, etc.). ) and restore the factory settings. 7. Test whether the system version has improved after the update. If the problem still exists, it is recommended to send the mobile phone to the nearest Samsung service center for testing.