Test rigs
Three fixtures do most of the repetitive work. They are built, not bought, because a fixture that matches your boards beats a general instrument you fight with. Each has failed in its own way and been rebuilt at least once; the log notes those too.
RIG-1 · rail sweep jig
A bed-of-pins jig that reads every rail at once and sweeps the input supply up and down while logging. It catches rail-order and brown-out problems that a handheld meter misses because the meter only looks at one rail at a time. Current is logged per rail so a soak trace is a file, not a memory.
RIG-2 · pogo fixture P4
The fourth revision of the pogo-pin fixture, matched to the current connector pitch. P1 through P3 are retired; P4 is the one with proper strain relief so a cable tug does not lift a pin mid-measurement. Boards sit in it for the peripheral walk so the same probe points are used every time.
RIG-3 · boot capture box
Rebuilt 2026-09-11 after the level shifter on the old one died and silently inverted a line, which cost an afternoon of chasing a board fault that was in the rig. The new box isolates the capture side and buffers the console so boot-catcher reads it cleanly. Lesson logged: suspect the rig before the board when only one board "changes behaviour".