I followed the procedure at https://kb.ettus.com/E320_Getting_Started_Guide#Autoboot to put my USRP E320s into autoboot mode. That procedure worked, but when testing it on one unit, it stopped autobooting after about 10 power cycles. Subsequent power cycles did not fix the problem, but pressing the power button did cause it to boot. After that, it autobooted again, but again stopped autobooting after a small number of cycles. I tried the same procedure with 3 other USRP E320s. I periodically power cycled them and after 4 cycles, one of the 3 didn't boot, even after pushing the power button. So I've seen two failure modes with booting, one which is recoverable by pressing the power button and one which is not. I'm not sure if they are different symptoms of the same underlying problem or if they are two separate bugs, but I'm hoping there is a workaround for this issue. After speaking with colleagues from a partner company who also use E320s, they say 10% autoboot failure is consistent with what they've seen from E320s as well, so this is not an isolated issue with the two or three USRP E320s.
