I had the same problem on My iPhone 5s and as it is jailbroken I could do a little bit of investigation. Here is what I have found:
I power on the iPhone, bong bong noise comes. I go to the CrashReporter folder and there are a lot of log files. In one of those log files, I saw the following:
Jul 12 03:45:43 SpringBoard[210] <Error>: *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'cannot hide defunct contexts without a mainWindow -> screen=1 (connected=0) requester='''defunctScreen''''
*** First throw call stack:
(0x1824f6950 0x18e9fc1fc 0x1824f6810 0x18302edb4 0x10006f304 0x1001ca0e0 0x10008599c 0x1000918bc 0x18692d8f0 0x1824b6890 0x1824b67f0 0x1824b4a14 0x1823f56d0 0x1880d9c0c 0x185526fdc 0x100021da0 0x18efefaa0)
Apparently, as indicated earlier, the issue is that there are no screens attached.
I hope this helped you! :)