ESP32 Rainbow QA - A tale of three boards We’ve shipped a few hundred ESP32 Rainbow boards-most are perfect - but a few failed QA. Here’s how we tracked down and fixed three real-world faults: no sound from lifted headphone jack pads, USB not enumerating due to a mis-seated ESD IC pin, and a flaky touch keyboard from poor ESP32 module joints. A bit of microscope work and reflow brought two boards back to life (one’s now a donor), and it’s a great reminder why we do final assembly and full QA here in Scotland. 02 January 2026