Why does my phone say No Service?

[WPCentral Question]

my phone says no service

My phone since yesterday it says GSM MODE and now I cannot receive nor make calls..

Please assist

 

[charlatan1978]

Re: my phone says no service

I would probably look to reseat the SIM card.
Had you done anything to the phone before it happened? e.g. upgraded it to Win10
You could also check with your phone operator to see if there are any signal issues in your area.