My wife's NT 16GB without n2a does that every couple of weeks. I just let it sit for 5-30 minutes, then plug it in and most of the time it comes right on. When it doesn't, I just repeat and eventually it comes on. Never takes more than a couple of hours.
Just flashed an AOKP CM 10.1 with 10 finger multi touch to my internal and it is awesome.
Posted from my 16GB Nook Tablet running Jelly Bean AOKP CM 10.1 with 10 finger multi touch over WiFi tether on my LG spectrum on Rooted unlocked bootloader OTA ICS.
Thanks go to the huge list of people it took to make all of this work.
LG Spectrum -- Rooted and running CM10.1 official M2 thanks to TDM (and too many others to list).
B&N Nook Tablet 16GB -- running CM10.1 with 10 finger multitouch