Hey bud. Sorry you are having the issues. You have done a lot. And no need in just replacing more parts. I am in now ay trying to divert you from this site. It is a great site. But I am rather, offering you another avenue for help that specializes in the 4th gen. If you are not a member already, please sign up and post your question. Very, very knowledgeable people there.
https://www.z28.com/