I got myself a T12 clone station recently. I’ve only had a junk iron that plugs into a wall socket and heats up to full blast whatever temperature with the big giant tip. Not very useful for more precise work.

I had this damaged Arduino Pro Micro clone sitting in my box of random stuff. At some point in time I had decided cut out out 4 pin headers for some reason. Damaged the corresponding traces in the process.

The repair worked! It was the MOSI, MISO, CLK, and RESET pins on the board. These pins can be used to have this board flash another Arduino board.