Soldering
Soldering is where a circuit becomes permanent, and every step and fault in this trainer is shown in a real photograph. The first three tabs walk the jobs: making a joint on a board, wiring onto the pads of your build's modules, and recovering parts from a dead board. The rest build judgment. Study what each fault looks like, check your kit, and then take the Diagnose drill, which shows you unlabeled photos and asks you to name the fault.
What are you looking at?
The through-hole steps and most fault photos are from the Adafruit Guide to Excellent Soldering; used with permission. The wire-to-pad photographs are our own bench. Iron temperatures cross-checked against Hakko.