sm86, you're a genius!
Same exact thing happened with my phone. It just displayed the charging screen with the lightning bolt after many hours of charging. I tried the reboot trick. Nothing happened after I booted into Windows. I unplugged the USB cord, let it die (took 5 seconds), plugged it back in, and the Apple logo appeared. What a welcome site.
Thanks for saving me and others time and money with your excellent DIY instructions!