Beaglebone Black won't power on

I was working with the BBB board and suddenly it powered off and never came up again whether through USB or the power cord . i was working with very simple project that consists of a switch button and a LED which i guess we are all familiar with.
when i try to connect the BBB through USB or power cord the power led just flashes one time and go off again. what should i do ? is my board dead ?

how are you powering this LED ?

through the 3.3 v pin from the BBB

I have a same problem.
but, it happened to my BBB because one of my wires has a connection to the below of my BBB. and I think is dead! :frowning:

for the record same as you in my BBB power led just flashes one time and go off again .