Why did my Lumia 520 restart when I was on call?

[Windows Central Question]

my lumia 520 get restart automatically when i was make call?

 

[Harrie-S]

my lumia 520 get restart automatically when i was make call?

What could have happened is that you battery is a little bit loose, in the housing, and was disconnected for a moment and triggering a restart.
You could try to shake your phone to see if you can create it again.
If so put some paper between your phone and housing to secure the battery "position" so it can not "move" anymore.