My 21 month old XR with very little use, started a Boot Loop after charging. I've tried everything including DFU but the damned thing won't even turn on. A local authorized dealer got the phone to boot and removed all the OS but could not re install any software at all. It just produces a message to contact APPLE. They initially sent me to the dealer. Don't know what else to try with this relatively new perfect shape XR. Any suggestions aside from using it for target practice would be appreciated.