bricked iphone 5s

Please, Please, PPPLEASEEE!!! can anyone out there in our community give me an answer to how i fix my once brothers iphone that was bricked completely after my terror son decided to press buttons a little too much for the iphones tech specs speciality apple make iphone my brother has given me now because he thinks i can't fix it at all. I want to prove him wrong and fix what is now My iphone 5s Model A1457, as i have heard bricked iphones or many phones of any kind can be recovered but I don't have any clue as to how i fix this lifeless iphone. It would be great if anyone knows how i can, preferably free, on how i recover a dead non working iphone, which was in full working order before my son got his little fingers on all the buttons, bless him, he is only 4, lol. my brother said the iphone is all mine if i could ever find an answer to this problem and fix this bricked iphone and it'd be a shock on his face if ever i actually could fix something i've never fixed before...especially an iphone lol, i sooo wish someone can help me. The iphone has not been dropped, or wet, it simply malfunctioned and turned off and now will not turn on or charge or go into recovery mode at all but someone said it is a possibility this challenge can be fixed....hope you can help. Thankyou, jojo,xxx