I recently brought a new iPod 4th gen for myself so I was going to give my brother my old one, I was clearing it off and he asked me if I would jailbreak it for him also so I entered it into dfu mode and plugged it into the computer which then said it was an unknown device and wasnt recognized in itunes either I plugged it out and held the sleep button but the screen remained black and then I tried charging it from a wall charger overnight but the screen is still black. What should I do?