Apple Logo Fizzles and Screen Goes Black

Hi there! I'm troubleshooting a 5C that was dropped on the ground while in it's rubber protective case. Cosmetically, the phone is in pristine condition and hadn't suffered any obvious physical damage.

Symptoms: The phone seemed unresponsive to a depressed power button and the display was black.

Attempted fix: I lifted the screen and reseated the battery connector. After another depression of the power button, the Apple logo appeared but soon fizzled out and the display returned to it's black state. I was able to verify power to the phone as the backlight was on and the vibrator motor was functional and responsive to it's switch. The home button also appeared to be functional.

The logical next step (for me) was to swap the screen assembly. However, after replacement I still have the same results. Here's a video link of the current symptoms. The Apple also has two vertical blue lines through it.

https://www.dropbox.com/s/fwrhswg85gcuor...

I have reseated all connectors to the logic board and hadn't found any loose components or connectors. Any thoughts as to what I should try next? Thanks!