This is what I've learned:
-some people can get the screen back by restoring firmware or performing a hard reset. It's worked for me but in just a few cases. If it works for you, then consider yourself lucky. Done.
-what is usually the case (and frustratingly so since you'll try EVERYTHING like I did) is that '''the battery has to completely discharge'''. Yep, put it away for a few days and then come back to it later. Avoid powering the unit on until everything is properly seated.
If you have a white screen, it does NOT mean the screen is defective; there has been hardware changes and the unit has to be drained of all possible charge to have a fresh boot - much like any computer.