iPhone 4 Dock Connector
Definitely agree on the moisture sensor. I had to replace mine because it got real wet a few months ago. I was able to keep it working for a while, but then the mic eventually died.
The logic board removal was questionable for me. I felt like I didn't have to, but it made it much easier to properly reinstall the speaker enclosure.
I had two different little pieces of plastic on my replacement on the mic that I needed to peel off. You may have left some on. Not the easiest to check, but a possibility.