Best way to avoid prematurely retiring your Pi when making external connections Even seasoned hardware engineers can make mistakes, this is is an easy step to significantly reduce the probability. If I am fitting a header to a Pi this is my preference, even if using a board. As its easier to debug connections and pin positions. The headers have a little flex along the length. invert the Pi PCB and arrange so the header is mated along its length to the PCB. Suggest solder opposite corners then inspect to esnure the header is flat against the PCB. Then solder at ~opposite thirds and check its flat against the PCB again. If required you can reflow the joints and apply pressure to ensure header is mated along its length against the PCB. If its not, it will not mate correctly and probaly result in a dry joint or damage. Don't overheat the joints if re-flowing a soldered joint. Let it cool and come back if you have to. When soldering, a little non corrosive rosin flux is always helpful. The X's below are where I start XO OO OO OO OO OO OX OO OO OO OO OO OO XO OO OO OO OO OO OX