Dropped 5c doesn't work but vibrator cycles

A friend brought me her 5c. She flipped it out of her sheets while making the bed, so I guess the impact was pretty intense. The phone does not function at all now. No screen, no vibrator, does not sync to iTunes. However, when plugged in (either to Mac or wall), the vibrator cycles twice every 5 seconds. It did not respond to a hard reset. I opened using the iSclack (great tool, BTW) and there is no visible damage. All connecters were intact, but I removed them and reattached them anyway with no success. Also tried a new battery with the same result.

Help!!

-Milo