I have a retina ipad mini that has been working great until today. I just got a brand new 15" rMPB and plugged the iPad in, and it keeps beeping. When iTunes is open, it shows the iPad connecting and disconnecting repeatedly. I am using an official apple lightning cord, and have tested multiple known good cords, but still get the beeping. I thought it could be my computer, but when my iPhone 5s is plugged in, everything works as it should. I just wiped/restored the iPad and it is still having the same issue. Does anyone have any idea what is going on? Any help is much appreciated!