My third Orange Pi Zero came last week, yesterday I plugged it and had heating issues... So I started reading, learning and testing....
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)
All with (newish) Sandisk Ultra 16 GB Class 10
All new formatted (SD Formatter) and burned/validated (Etcher v1.0.0) with
Just a heads up, I think the bigger issue between the revision 1.1 and 1.4 is that they removed the "U5" buck AVCC/RTC 3.3V converter, Instead in its place they put a "R9" 0 ohm resistor from the GPIO 3.3v regulator "u55". As such it makes sense that they removed the "Q11" gpio voltage enable switch, since now that switch must always be on.
In testing the voltages, the Rev 1.1 GPIO VCC is 3.37v, whereas the AVCC/RTC Vcc is 3.27v.
For Rev1.4 though, the GPIO/AVCC/RTC Vcc is actually 3.4