iFixit screen not working but original cracked one works.

So, my sister cracked her iPhone 6 the other week and I decided to be nice and order a kit to fix it for her. I got the kit today and followed all the steps to replace the screen from the official guide on the website. I thought it was all going smoothly until I tried to turn it on with the new screen, and nothing. The LCD pannel would turn on, but no apple logo would come up and then it would shut down a few seconds later. I tried a bunch of methods such as booting it into recovery mode and using iTunes to reset it, but that was to no avail... I then decided to put the old cracked display on and sure enough, it booted with no problems. I am really out of ideas on what to do besides possibly sending back the display I got from iFixit to see if it has any defects that would cause it to have this issue. Any help would be super appreciated!