iPhone SE won't turn on

I changed the LCD on that SE a while ago (like 2 months), because my friend somehow applied too much pressure on the screen and broke it (everything else visually seems okay. Since then it worked perfect with the new display. Yesterday his battery drained completely and when he came home he plugged in the phone to the charger and left the phone. When he came back he noticed that the phone is turned off and hot (so I’m assuming it’s charging) but it gives no sign of life. I tried to plug it in computer to see if itunes recognize it, disconnecting the battery and plugging it in to charger also while holding down power button, disconnecting everything except battery and charging connector etc. I pretty much tried everything I could and the phone still isn’t turning on.