Beaglebone black is not booting..........

Hi friends,

This is Vikas here …I am facing problem with my beaglebone black its not booting but all the three USER LEDs 1,2 and 3 are contineously ON when i connect it to my laptop.
plz help me to make working my BBB. and in case if lossed my data from angstrom how do i get it recovered from BBB.