network problem call not working mobile data not working

If your mobile data doesn't turn on at all, try these steps.

1. Reset your phone's network settings. Find the "Reset network settings" option in your phone's Settings app. After the reset, do a hard restart by holding the phone's power button and choosing "Restart" from the options menu.
2. Check your phone's network status. First, turn off its WiFi. Then, go to Settings > About Phone > Status Information > SIM card status. You should see the following settings: Mobile network state: Connected, and Service state: In service. If you don't see those settings, remove/reseat the SIM card from the slot on your phone's side. You can use the sharp end of a paper clip to reseat the card's tray.
3. If none of these work, contact your cellular carrier.