Help samsung galaxy mini 2 won't start

[cpper]

Hi
Today I was on whatsapp on my samsung galaxy mini 2.I discovered than the wifi was not working anymore so i turned it off and on,but it turned off automatically.So i restarted the phone,long pressing the power button.
But the phone didnt start anymore.What happend ? I tried to plug the battery off and on,but still not opening...
The charger was plugged in when this happened...

Any idea ?
Sorry for my english but i'm freaked out

 

[El Presidente]

Did you notice if the phone was hot at all when it turned off?

Have you tried another battery?

 

[cpper]

it wasn't hot,I havent tried yet another battery.Anyway,the battery was fully charged when i restarted the phone.