I found that the BBB just sometimes just not boot, then I would re-flash the system run again. I then found that if the ethernet is connected and I boot from SD card the internal flashing algo start. One can check it with ‘ps ax’, the whole sequence of events can be seen … first a dd with dev/nul, then the creation of the flash etc, this is WITHOUT the boot button connected. It does however also works as advertised , with no ethernet connected, then one has to keep the boot button in, with power on to get in the flashing eMMC mode.
I personally think this is not suppose to be so, it should ONLY flash the eMMC if the BOOT is pressed during power up…
This render a non boot BBB is you switch the power off within one hour, as the eMMC is then not fully programmed, and one cannot see the leds is now toggling the flashing sequence, as it always toggle, the only way I could detect it was to look at the processes, and see the dd etc
I am using the BBB supplied angstrom, with the latest image before the angstrom site went down for ‘THREE WEEKS’ !!!