iPhone SE won't display after lightning connector replacement.

So I was wondering if I could get some advice. I opened up and replaced the lightning connector on the iPhone, but after testing it the headphone jack wasn't working. So I decided to open the iPhone again to see if there was a problem with which I installed the connector I found none. The problem is now the screen won't turn on and I have no idea if the connector got messed up or the screen is broken. I connected the iPhone to my laptop and iTunes detects the iPhone and even it's name, but I haven't been able to get any other response. I am stumped as to what the problem could be has anyone else had a similar issue?

P.S. I noticed that the cable battery cable seems to have some 'styrofoam' looking part in it and I don't know if it's relevant.