well, that damage was there when I opened it up and took the foam pad off.

Most modern electronics is assembled largely without humans. Solder paste is automatically screened onto the board, and then the components are placed on the board by the appropriately named "pick and place" machine. Very cool to watch! The board then goes through the reflow machine that gradually heats up the board and melts the solder paste. It's just the final assembly of the board with the display and battery that requires some humans to be involved, and while humans can be trained to make very few mistakes, they do make mistakes.

Tests at the end of the production line catch most of the problems that might exist... some of which can be due to problems with the soldering process. There are always weird things like intermittent connections that can get through the end-of-line test and out to the customer.

Steve in Peoria