Beaglebone Black No Lock on DAC

I flashed Volumio on an SD card, everything ok, placed it in my BeagleBone Black and boot from it. Open Volumio on my computer and configure it to connect to my NAS, everything works ok, then when I connect it to my Twisted Pair Audio DAC, Bufallo IIIse, thru the Amanero USB port, and boot the beaglebone black, the DAC Locks while booting, but it looses Lock right after the boot, why??? Volumio still runs, I can see it from my IPAD or computer, I can browse the NAS, but if there is No Lock, there will be No Music??? What did I do wrong? or is there anything I should do? or is my beaglebone damage, for any reason? Help!!! Anyone…

Alex