Why can't I find my phone? It won't ring

If you have Find My iPhone enabled on the device, log into www.icloud.com on the computer, select the device. You will be able to not only locate the device on the map, you can also click on Play Sound. You should hear it as well.

The phone has to be charged and in an area where a wifi or-cellular network is operating and you must have data on it if it fails to meet any of these conditions u may not find your fone ...