I have a Lumia 520. Yesterday it was shutdown and if I try switch on, phone is not answering. I try a hard reset, but it is not solve my problem. Then I try Windows devices recovery tool and it solved the problem. But the phone 3 minutes after restart automatically. It do this continously. I do not know why. I try again use windows devices recovery tool but now it write can not recover my phone. I am not know what I do. Can you help me?