Cameras & Flashlight Stopped Working After Camera Replacement

It sounds like you either incorrectly connected the replacement camera or it is defective. Even when ordering from a solid vendor like iFixit, you can still get the occasional dud. Small parts are notorious for poor quality. I can't speak for iFixit but I doubt they test every single part they get from their suppliers.

So try to re-install the replacement camera one last time, then go back to the old, cracked one. If it is clear that the replacement camera does not work, call iFixit and have it replaced under warranty.