No display, just a double vibration?

[Jbeaumont1991]

I have recently replaced the LCD on my iPhone 5 after accidentally dropping it from a height. Now, after carrying out the replacement procedure extremely carefully with a new LCD, I am met with a LCD that doesn't work at all and the double vibration you'd usually get when plugging in to charge your phone every three/five seconds.

I wondered if anybody knows why the phone is vibrating like this, is it a signal that something is broken inside the phone? I initially thought it was because I had tried to test if the LCD was working without closing the phone back together completely.

Any advice/input would be greatly appreciated,
Thank you.