I finally figured out the issue. The phone turns on completely fine and everything works when the flex cable for the touch digitizer and 3d touch is unplugged. I applied some isopropyl alcohol to the back of the screen, mostly around the areas where i could see components. After sitting for a while, I brushed it off and used a heat gun on it for about five minutes, and when i assembled the phone again everything was fully functional except the haptic feedback.