After Ligthning Connector Change, reception is down to -110 dbm. HELP!

Hey.

I changed my iPhone 5s' ligthning connector a few weeks back, everything went smooth, and it works - no problems here.

But when i went to turn the phone back on, the signal was suddenly getting more and more vague, and it's now down to around -110 dbm (translated: unimaginable bad).

Sometimes i hit good spots, when i'm out and about, but 80% of the time the signal is unacceptable.

I would suggest that this a hardware problem, of course because of the fact that, before the ligthning connector repair, there was no such problem - and then after, BOOM, it just suddenly was there.

I hope someone can give me a little piece of advice, or lead me the right direction of what i should do.

Kind Regards

Christoffer