My Samsung Galaxy S3 has this annoying habit that, whenever I try to do something like connect to a network, or open Candy Crush, after 20 seconds my phone will turn off, and on, and then keep turning off and on, the timing at which it turns off after turning on is variable: sometimes I have the option to enter my PIN, most of the time not.
Up until this point I solved it by plugging it in, and stop attempting to do anything with this phone that I cannot do on my old Nokia. The problem this time, is that my phone has entered a state of isolation: I cannot text, or receive texts, cannot call and the symbol which normally shows how good my connection is to my network has been replaced by a stop sign. How do I get rid of this?
Also, my battery occasionally drains: from full to 0 in under 2 minutes.
Placing my SIM into a different phone allowed me to text and call, so its nothing to do with that.