Mobile data signal horrible after repair

So I recently replaced my, battery and charging port on my phone and noticed right away that my mobile data signal was horrible, like at home I would have no data what so ever, out in most places I would have it but not as strong as it used to be, anytime I walked into a building it was gone. I got really fed up with it and put my old charging port back in, it barely charges the phone but the data signal is normal again. How can I fix this, is it a bad charging port?