Black screen on startup only when plugged in wall adapter

It Sounds like you've knocked something else loose, or have the incorrect replacement part. Try your old battery if it works right away, you might have the wrong part. look over all your connectors and verify they are all connected fully, and I would even unplug each and reconnect every connector . Also, double check to see if you have the correct battery part number. Also get a magnifying glass and flashlight and carefully look over all the inside area of the phones internal connections. You can also sit the open device in a well lit area and take a close up photo of the inside area from a different phone then look over the photo by zooming in 150, 200, or 300 x take several photos from side angles that might reveal a loose connector or bad part.