I was rooting my phone I got to the point where I accepted the 4.4 update it downloaded installed shut off and that was it. I have tried every button combination, It had plenty of charge, and just to make sure I plugged it into a wall charger for 20 minutes. Any suggestions? The screen doesn't come on at all. Thanks, Garrett.
hold power button for 1 min if you feel the phone vibrate that is good.
now try holding Volume Up + Power will it boot into the bootloader.
If yes great time to restore to stock
If No then your phone is hard bricked and you will have to get it replaced.
one easy way to find out if your phone is hard bricked is to plug it into the computer and see what drivers it tries to install
if it say qhsusb_dload then i know for a fact that your phone is Hard bricked.
If that is the case call your carrier or go to a local store and tell them that your phone was on 4.2.2 and you downloaded the 4.4 OTA and it rebooted to install it and now it won't turn on at all they should give you a brand new phone because it was the phones problem.
When you get your new phone please post here first with What Carrier Moto X you have and what android version it is on 4.2.2 / 4.2.2 Camera Update / 4.4. and i will help you get your phone rooted and up and running correctly
Good Luck My Friend and please don't be afraid to ask for help