There are a few reasons why your iPhone might say "No Service" and have "SOS" at the top of your screen. Here are a few possibilities:
- You are in a location with poor cellular reception. If you are in a rural area or a building with thick walls, you may not be able to get a good signal. Try moving to a different location to see if you can get a better signal.
- Your SIM card is not inserted properly. Make sure that your SIM card is properly inserted into your iPhone. If it is not, your iPhone will not be able to connect to a cellular network.
- Your iPhone is in Airplane Mode. Airplane Mode turns off all wireless connections on your iPhone, including cellular data. Make sure that Airplane Mode is turned off.
- Your iPhone is locked. If your iPhone is locked, you will not be able to make or receive calls. Unlock your iPhone and try again.
- Your iPhone has a software issue. If you have tried all of the above and you are still seeing "No Service" and "SOS," your iPhone may have a software issue. You can try restarting your iPhone or updating to the latest version of iOS. If that does not work, you may need to take your iPhone to an Apple Store for service.
I hope this helps!