My BBB Rev 3 was put into service 3 weeks ago. Noticed that board would periodically hang and need reboot. The board then ceased to start up at all. Board emits a high-pitched whine with no LEDs (including power LED) lit or flashing. No signs of life except the whine. Disconnected all but the wall-wart (5V 2A switching). Still LEDs flashing or lit, Pressing reset and power produced no result. Checked power voltage on connector and voltage was perfect. Un-jacked power (at BBB connector) and re-jacked. Still no LEDs lit or flashing. Still generating the high-pitched whine.
This morning, after submitting an email to RMA, I decided to try powering from USB to bypass the regulator. As a baseline, I connected the 5v wall-wart. This time, the BBB booted perfectly. No whine and LEDs now happily flashing. Connected over ssh/ethernet and logged in successfully.
Has anyone else seen this intermittent failure?