Chosen Solution
After being thrown in a pool with my 2 month old 32gb 5S, I completely disassembled to dry/clean it. :( It is currently drying in a sealed container of dessicant. However, while disassembling, at one point I picked up and turned over the back half, and this little triangular(ish) metal piece fell out. I have checked countless disassembly and reassembly guides, pictures, and videos, and I cannot spot it anywhere. Can someone please help me??? http://i.imgur.com/oJgxrjs.jpg
This is the washer under the screw hole on the top end of the logic board
Step 31!!! There are three small pictures, click each one and enlarge! I had NO idea where this thing went! iPhone 5s Logic Board Replacement