Auxiliary port issue S4

[AC Question]

I bought this phone from my brother in mint condition and very cheap. He bought it from one of his friends and claims the auxiliary port has not worked since he obtained the phone. OK so I order a new auxiliary port off of the interest receive it and install it. Fair enough and easy enough except the auxiliary port still will not work. Before you suggest trying several plug ins, of course I have Anyways I used this as an excuse to buy a nice pair of bluetooth headphones, but I would still like the option for obvious reasons. Any help? Is it a software or hardware issue? Is this common? Any information is welcome.