No signal error is coming

I have this problem and after looking for awnsers i cant find something that repairs this problem and i changed some network ic (i dont know what they call it) and my problem solved but before doing that restart your phone and check. Remove and reinsert the SIM card and check. Switch between different network modes and control. Check with any other SIM card working, and that your SIM card or your network operator may be having problems and after that you need to bring your phone to repairers to check.