Samsung Galaxy S2 i9100 Won't do absolutely nothing.

[BrownieEm]

I have a certain problem with my Samsung Galaxy S2. It's a bit old now, It has about 4 years with me. A couple of days ago, I was charging my phone and it was a bit hot. And I recieved a call. I answered it, and the phone went black. I tried turning it on and, nothing. All it showed was a blue screen with a black circle on the top left corner. The phone hasn't gotten any bumps or has fallen out of my hands or anything of that nature. I decided to turn it off, take out the battery and not touch it for a day. I placed back the battery the next day and, this time, nothing shows up. Today, I decided to use it again, and connect it to my laptop, and the laptop detected it. I really don't know what to do. Is there a fix for this problem? I'd appreciate your help. Thanks.