why my phone is not working?

[WPCentral Question]

in February 2014 i bought lumia 520 mobile phone and it was worked well for a year and then it got repaired for 1 time because of software problem and then it was stopped working as it was no opening any apps and getting switched off automatically ,,..i gave it for repair in Nokia store but it is not getting repaired ...please help me to sort out this problem

 

[jmshub]

We may be able to help, but we'll need more information. What is happening? Is it not launching any apps at all, or is certain apps not working? The standard first step if you're phone is misbehaving is to perform a hard reset. Be advised that you can lose data if you are not backing things up.

The procedure for doing so is here: Reset my Windows Phone 8.1 | Windows Phone How-to (United States)