This might be your issue. It was with mine.
https://groups.google.com/d/msg/beagleboard/Ya2qE4repSY/q8_WkLcH5TwJ
On Tuesday, January 14, 2014 1:35:59 PM UTC-8, Steve Rayner wrote:
I've connected the Beaglebone Black via USB cable. I'm using Windows7 and
I've installed the USB driver. I can
Mine has a similar issue, right out of the box. Certain (most?) microUSB
cables are loose in the socket, which causes the system to reset if it's
bumped into or moved around. It's not enough of an annoyance for me to RMA
the unit, though.
Jon
On Wednesday, December 11, 2013 4:46:51 AM