Here's a fascinating video made by a programmer from the US who decided to make an iPhone 6S practically from scratch. After thinking about this project for 9 months, he "dove in with both feet." He traveled to Shenzhen, China and went shopping in the bustling back alley markets of Huaqiangbei to find all of the many parts, having to return numerous times to exchange pieces that didn't work or to get even more parts.
This project took him months, and it's a lot of fun to watch the process. He does have some help, from a friend of his who takes him around and translates when needed, to a cell phone repair shop that de-bubbles the screen and digitizer subassembly to a cell phone repair school that helps him with some of the parts he needs.
He calls his video Strange Parts, and refers to it as "Adventures from the technological fringe." The amazing chaos of the city itself is worth the watch. A must-see for anyone interested in DIY and travel adventures.