I have a BeagleBoneBlack rev C. powered via cape pins (the cape is a custom board which takes 12v power and converts it to 5v to power the beaglebone). It consistently boots up ok (never experienced an ethernet PHY issues that others report).
The board runs a simple python script that exposes a TCP server and allows sampling GPIO pins.
Everything works fine for hours, until after ~50 hours (not consistent, it takes between 40 and 50 hours to reproduce) the board freezes - stops responding via network, LEDs stop blinking. After a repower the board gets back to normal for another ~40 hours. During these tests the board sits in a closed box.
When the cape is connected to another power supply and sits on my desk, there is no problem whatsoever - it keeps running for at least a week without issues.
Did anyone encounter a similar issue? Or has any leads on how to investigate this?