I have a Casio G'zone Commando 4GLTE. My phone will power off unless on charger. How can I tell if this is a battery or phone issue?
Take battery out and plug in charger. Should come back on. If it doesn't, could be the battery. Do you have a charging indicator on screen with the phone on or off, does it tell you it's charging? Think of it in terms of a car that you are testing the alternator (charger) or battery (battery) on.
