My phone started doing this today. It was on this morning, no problems. I got a notice saying it was low on space, so I deleted a few apps (all stuff that I had downloaded, nothing that could cause a problem). Then I opened my Kindle app and began deleting books off the device. I did that for 3 books, everything was fine, then it froze as I was deleting the 4th book, and then entered the endless restart loop. I removed the battery, thinking that would help, but it didn't. So I removed it for a longer period of time, but still nothing. I'm just caught in the loop, but I don't have enough expertise to know what to do next.