S4 mini won't turn on or charge

A

AC Question

I was just on what's app texting, locked the screen and went and did something for a few minutes came back tried turning it on nothing. I tried holding the volume - home and power buttons simultaneously still nothing, switched to a fully charged battery and it still wouldn't power up, tried powering it up while it was connected to the charger still nothing. Basically I ran out of ideas could someone please tell me what has happened to my phone?

P.S Never really dropped from me and it never fell in water.