Installed new battery but phone doesn't turn on now

iPhone SE 1st generation worked fine before but battery drained quickly, so I ordered a new battery from ifixit. I installed it with ifixit tools and followed all the instructions, but now the phone doesn't turn on. I charged it for hours, but that didn't work. It doesn't connect to my computer (or itunes) when I connect it with a USB either. I took it apart again 2x and put it back together, all connections seem solid! Charged again, still no sign of life. Please help, I need my phone!