Why isn't my front camera and head speaker not working?

I replaced my battery the other day and now when I try to call anyone, I can only hear on speaker. And I discovered yesterday that I couldn't use my front camera either. I've tried taking it apart and making sure that everything was put back into place properly and I wiped down the connectors with a qtip and nothing is working. (Im 18, my dad bought the kit for me to do it myself because he encourages ((a little too often with far too big tasks sometimes)) that we ((my siblings and I)) take charge and do stuff ourselves. Such as this.) I'm getting really frustrated and I don't have the money to take it into the store. Help!