1. Restart your phone and make sure that your phone is not in
Flight mode.  2. Check the signal strength on the phone screen,
and move to an area with better reception. If you continuously
experience low signal strength in a certain area, the mobile
network coverage may be insufficient there. With Netradar you
can check mobile operator coverage maps. The maps are available
at www.netradar.org.  3. Change network selection mode to
automatic. Select Settings > mobile+SIM and tap SIM settings.
Under Network selection, open a list and select automatic.   5.
Check that your SIM card is fully inserted. If possible, try
your SIM card in another phone and/or try another SIM card with
your phone.    • Note: Do not use SIM cards that have been
modified to fit the SIM slot. If a regular SIM card has been cut
to a smaller SIM format you will have to contact your operator
to order a replacement SIM.