This fantastic machine has been used heavily by me since the end of 2013, and it was updated right through 11.0.1 with no problems. But now it’s apparently not charging or dead. It’s been plugged in for two days, I tried cleaning the lightning port contacts, I swapped chargers and cords, and all I get is this on screen: I tried holding down power and home button, no change. Is there anything else I could try? Thanks!