I have just got a Google Nexus 4 and power it up, but the phone's lock screen displays "No SIM card" error message. It seems no way to use the device. How can I get it working?
Because there is no SIM installed. As part of the setup process, you will have to insert a micro SIM card into it.
* A SIM card is used to identify a unique subscriber on the network and its tray is located on the left side of the phone under the volume button.
* Power it off and use a thin pin into a small hole which is just above the tray door for ejecting the slot. And slide the micro SIM card gently inside it.
* Finally push it gently back into your phone.