My iPhone won't turn on after a battery replacement.

I replaced my battery because my phone kept randomly dying and the charge wouldn't last long. After prying the battery up from the left side by my volume buttons, I connected the new battery sensor and re-connected my LCD sensors. I then turned the phone on just to make sure that it was working properly. The screen turned on so I turned it back off and place the metal covers or brackets over my LCD sensors and over the battery sensor. I put the screws by the charging port back in and when I tried to turn it on the screen remained black. Then when I tried turning it on by applying pressure to the power button or plugging it into power, the sensors by my front camera and earpiece seemed to heat up. They remained warm until it was unplugged or pressure wasn't applied to the power button. I think took apart the pieces by my front camera and earpiece and nothing seem to be blatantly wrong with them. iTunes still recognizes my device when I plug it into my computer. None of the LCD sensors seem to be damaged in any way. Please help I don't know what else to troubleshoot.