BBB Rev C Random Power Downs

Hello. I got my BBB before XMas, but havent played with it much. Now its started to randomly turn off. I have ran it off the 5v circular plug, as well as off USB. Its still just dying. Seems to only do it if I have items plugged in. When I unplug everything, it ran 24/7 for about a month. Ive tried having a power source (batteries) and USB (plugged into a wall adapter). Still kicks off, so its not say a kernel panic where USB stops working or something, unless its not kicking over to the other source..

Any ideas? Havent seen anything thats standing out, just occasional ethernet phy errors that come and go..

I noticed the same thing with mine - it would randomly reboot if I had it both connected to USB to my computer for connectivity and also a 5v (2A) power supply. I had just assumed it was a loose connection to the 5v jack that was causing the 5v to blip if I bumped things, causing a reboot. In my situation I didn’t need the 5v connected as it is running fine off the USB-provided power so I just am running it off the USB for now. Maybe it wasn’t a faulty 5v power, but I never went back as I had other things that made this issue not worth persuing at the time.