When I try to turn it on, it will go through the boot animation and then end with the Verizon logo. The screen turns off afterwards. If I leave it alone, it eventually reboots itself again.
I've had this happen a couple times in the past but it always recovered after a couple of reboots.
This is an unrooted phone. The only sideloaded app installed is SwiftKey Beta. It has that latest 4.4.2 update. The battery was ~50% when it rebooted the first time. It's set to use ART runtime. I've tried clearing the cache from the bootloader AND from fastboot. Neither helped. I really don't want to restore to factory defaults if I don't have to. Advice?
SOLVED: My solution in 3rd post.
TL;DR: Reflashed stock system partition. Turned on and plugged in overnight. Hard reboot via holding down power button for 7-10 seconds. YMMV