- Restart your phone.
- Check that your SIM card is fully inserted. Do not use SIM cards that have been modified to fit the SIM slot.
- Your phone may be SIM locked, which prohibits using a SIM card from a different network operator.
- If possible, try your SIM card in another phone.
- My Lumia phone does not work or respond as expected
- Cellular data connection or MMS sending doesn't work on my Lumia 521 when using "Wi-Fi Calling"
- My Lumia stays at the spinning gears, how do I get it to stop?
- I cannot make a call on my Lumia phone
- I cannot share my Lumia’s internet connection with another device