Our debugging journey at VCFe began right at powering up the board the first time, when something got real hot real fast. Fair enough, and easy to spot. There was a mixup of VCC and GND at U29, a 74HCT244. Embarassing, but not that critical, as U29 is only used to connect the joystick ports to Port A of the VIA. We can live without them for now. The mixup likely happened when I transferred the IO-board schematics from KiCad 6 to 7 while updating the symbols from the current library, which happened to be different than the old ones.