My third Orange Pi Zero came last week, yesterday I plugged it and had heating issues... So I started reading, learning and testing....   Setup: OPiZ-1: 256 MB, no SPI flash - Has extension board plugged - for comparison OPiZ-2: 512 MB, with SPI flash OPiZ-3: 256 MB, with SPI flash (new one with problem)   Test conditions: All with (newish) Sandisk Ultra 16 GB Class 10 All new formatted (SD Formatter) and burned/validated (Etcher v1.0.0) with