Jailbroken apple tv 2 Unt. on 5.3 wont start

i was going through it, then all of a sudden it froze, then tried to boot up again but never did. i tried to unplug it and in again. Doesnt do anything after the apple logo, the screen stays black with the white lights flashing. luckily i have another unt. jb apple tv 2. but rerally wanna get this fixed. any suggestions?