A CAT scan for your board — a soldering check-up, no firmware needed. I'll connect over USB, look at every pin the way a multimeter would, ask the radio to identify itself, scan the I2C header, then reboot the board and see whether its firmware comes up.
Supports ESP32-S3 boards only for now — Nuggets, Nibbles, the Pusheen puck and the DEF CON badge. The ESP32-S2 USB Nugget and the ESP8266 Wi-Fi Nugget aren't supported yet.
What the vet can see: rest levels with only the chip's own pull resistors, whether neighbouring module pins are shorted, whether the LoRa radio answers over SPI, I2C pull-ups and devices, the flash and PSRAM fitted, and how the board boots. What it can't: LEDs lighting, microphones, anything that needs firmware timing. Nothing is written to flash.